Daily Safe : Radiation Safety Handling

Alpha particles ( a ) are relatively slow and heavy.
They have a low penetrating power - you can stop them with just a sheet of paper.
Alpha particles can not penetrate your skin. Due to the low penetrating power of Alpha particles, they are generally not a cause for concern, unless you ingest some material that emits Alpha radiation.
For the most part, materials that emit Alpha particles, also emit some Beta or Gamma radiation.

Beta particles ( b ) are fast, and light.
Beta particles have a medium penetrating power - they are stopped by a thin sheet of aluminum (such as aluminum foil) or plastic. Beta particles can penetrate deeply into your skin.

Gamma rays ( g ) have a high penetrating power - it takes a thick sheet of metal such as lead, or concrete to reduce them significantly.

Preparation

• Clearly label containers, equipment, and areas for the handling of radioisotopes with radioactive labeling tape. The labeling tape can be obtained from your institution stockroom or through an appropriate vendor. Minimize radioactive material work-space.
• Use absorbent material (benchcoat) and trays to confine spills and reduce the spread of potential contamination.
• Wear protective clothing. The minimum requirements include a laboratory coat, safety glasses and close-toed shoes. Wear disposable gloves, either single or double pair, depending on the radionuclide you are working with. Choose gloves that are appropriate for the chemical and other hazards in your experiment. If you are unsure about the type of protective glove to use call the Radiation Protection Office (RPO) at 495-2060.
• Traps to collect radioactivity may be necessary (as required under some permits) (e.g.: vacuum line traps). If a trap is not available, contact the RPO.
• Dedicate equipment such as pipettes and glassware to radioactivity work and avoid cross contamination.
• Plan your experiment so that mixed waste (i.e. hazardous chemical or biologically active combined with radioactivity) is not generated. If this cannot be avoided contact the Radiation Protection Office (RPO) for further assistance.

Equipment / SuppliesEquipment / Supplies

•     A Liquid Scintillation Counter for low energy beta radiation.
•     Portable Survey Meter with appropriate probe(s).
•     Disposable latex or plastic gloves.
•     Luxel Dosimeter (and finger ring, if assigned).
•     Lab coat, safety glasses, and close-toed shoes.
•     Containers for radioactive waste.
•     Pipettes dedicated to the use of your radionuclide.
•     Safety glasses (to protect from splash and shield from beta radiation).

Work Practices Work Practices

• Change your gloves often. Assume gloves are contaminated until proven otherwise. Do not leave the laboratory or touch things outside of the work space with potentially contaminated gloves. Remove gloves carefully from the inside out. Ensure that gloves are disposed of properly and wash hands immediately.
• Do not eat, drink, smoke, chew gum, or touch exposed areas of skin while working in a room where radioisotopes are handled. Be careful not to rub your eyes, scratch exposed areas of skin, or touch your hair when working with radioactive material.
• Use automatic or remote pipetting devices. NEVER pipette by mouth.
• Allow sufficient time for frozen stock solutions to thaw before attempting to withdraw an aliquot. If you are working with 35S-methionine, Cysteine, and Translabel® refer to the related worksheet for 35S volatility.
• Handle volatile compounds, which have the potential for vapor or gas release (such as Na125I or 35S-Methionine or Cysteine) in a functioning hood.
• Handle and dispose of spin (centrifuge) columns with care. Place used columns in a sealed container (capped tube or Ziploc® bag) prior to discarding into the radioactive waste.

Post-Work

• Promptly dispose of radioactive waste properly. Make a reasonable estimate of the amount of
• radioactivity in the waste and record on a radioactive waste tag.
• Lock-up and secure your radioactive stock solutions immediately after use.
• Survey yourself and work area for contamination with an appropriate survey meter. Decontaminate if necessary. Remove protective clothing and wash hands thoroughly with warm water and soap before leaving the laboratory.
• Note the results of your survey on your personal survey record of the work area. This is required if you are working with more than 1 mCi.
• Sink disposal must be done according to the approved guidelines. Do not exceed the posted daily limit for the radionuclide, unless otherwise authorized by the Radiation Safety Committee (RSC) in the permit.
• Participate in the bioassay program as requested by the Radiation Protection Office.

Basic Principles of Radiation Measurement : type of detector

Radiation entering the detector will ionize the gas and produce positive ions and negative ions (electrons). The number of ions to be generated is proportional to the energy of the radiation and inversely proportional to the gas ionization power. Gas ionization power range from 25 eV s.d. 40 eV. The ions produced inside the detector will contribute to the formation of an electrical pulse or electric current.

Primary ions produced by radiation will move towards the appropriate electrodes. The movement of ions will cause pulses or electric current. The movement of these ions above can take place between two electrodes when there are enough electric field. When the electric field the higher the kinetic energy of the ions will be even greater to be able to hold another ionization.

The ions produced by the primary ion is referred to as secondary ions. If the electric field between two electrodes the higher the number of ions produced by a radiation would be very much and called the 'avalanche'.

There are three types of detector gas field working on different areas which rooms ionization detector, proportional detectors, and detector Geiger Mueller (GM).

Room Ionization detectors (Ionization chamber)

As shown in the above gas characteristic curve, the number of ions produced in this area is relatively small so that a high pulse, when applying pulse measurement models, very low. Therefore, typically, measurements using ionization detectors applying current way. When you will use this detector pulse by pulse amplifier is needed is excellent. The advantage this detector is able to distinguish between the energy entering and working voltage required is not too high.

Proportional Detector

Compared with the above ionization region, the number of ions produced in the region is more so proportionately higher pulse will be higher. The detector is more often used for measurements by the pulse.

Seen on the characteristic curves above that the number of ions produced is proportional to the energy of the radiation, so that the detector is able to differentiate radiation energy. However, that is a loss, or a high number of ion pulses produced is strongly influenced by the working voltage and power voltage for this detector must be very stable.

Detector Geiger Mueller (GM)

The number of ions produced in this area very much, reaching a value of saturated, so the pulse is relatively high and require no amplifier pulse again. The main disadvantage of this detector is unable to distinguish the radiation energy into it, because regardless of the amount of energy it produces ions with saturated values. These detectors are the most commonly used detectors, because of the electronic terms is very simple, do not need to use the amplifier. Most of the equipment measuring radiation protection, which should be portable, made of Geiger Mueller detector.

Scintillation detectors

Scintillation detectors always consists of two parts, namely the scintillator and photomultiplier materials. Scintillator material is a solid substance, liquid or gas that will produce sparks of light when subject to ionizing radiation. Photomultiplier is used to change the spark of light generated scintillator material into electrical pulses. Radiation detection mechanisms scintillation detectors can be divided into two stages:

* The process of changing the radiation detector to spark a light in the scintillator material and

* The process of changing spark of light into electrical pulses in the photomultiplier tube

Scintillator material

Scintillation process in this material can be explained by Figure 4. In the crystal scintillator materials are ribbons or area named as the valence band and the conduction band are separated by a certain energy level. In the ground state, the ground state, all electrons in the valence band while the conduction band is empty. When there is the radiation that enters the crystal, there is a possibility that some of the energy will be absorbed by the electrons in the valence band, so it can jump into the conduction band. A few moments later the electrons return to the valence band with energy band activator materials while emitting sparks of light.

Spark of light is proportional to the amount of radiation energy absorbed and influenced by the type of material sintilatornya. The bigger the more spark energy is light. Sparks of light are then 'captured' by the photomultiplier.

 Here are some examples of scintillator materials are often used as a radiation detector.

Crystal NaI (Tl)

Crystalline ZnS (Ag)

Crystal Lii (Eu)

Organic scintillator

Liquid scintillator (liquid scintillation)

The detector is very special compared to the other types of detectors for liquid. Radioactive sample to be measured first dissolved into liquid scintillator so that the sample and detector into a single unit of a homogeneous solution. In this measurement geometry can achieve 100% efficiency because all the radiation emitted by the source will be "captured" by the detector. This method is needed to measure samples b low-energy radiation such as tritium and C14.

Issues that must be considered in this method is the reduced quenching the transparent nature of the solution (liquid scintillator) as it gets mixed samples. The more concentrated the sample concentration will deteriorate the level of transparency so that the spark produced light can not reach the photomultiplier.

Photomultiplier tubes

As discussed earlier, each scintillation detector consists of two parts, namely scintillator materials and photomultiplier tubes. If the scintillator material serves to convert radiant energy into light the spark photomultiplier tube is used to change the spark of light into a beam of electrons, which can be further processed as a credit / electric current.

Photomultiplier tube is made of a hollow tube with a light-proof photokatoda which serves as input on one end and there are several such electrons to double dinode contained in Figure 5. Photokatoda attached to the scintillator material, will emit electrons when it is light with a suitable wavelength. The resulting electrons are directed, with a potential difference, towards dinode first. Dinode it will radiate some secondary electrons when the electrons are.

Secondary electrons generated will go dinode dinode first second and then multiplied to dinode third and so that electrons are collected at the last dinode amount to very much. With a collection of electrons capacitor will be converted into electrical pulses.

Semiconductor Detectors

Semiconductor materials, which were found relatively more recent than the above two types of detectors, made from group IV elements in the periodic table, namely silicon or germanium. This detector has several advantages, namely more efficient than gas field detector, because it is made from solid, and has a better resolution than scintillation detectors.

Basically, insulating materials and semiconductor materials can not forward an electrical current. This is due to all the electrons in the valence band while the conduction band is empty. The difference in energy levels between the valence band and the conduction band in the insulator material is very large so it does not allow electrons to move to the conduction band (> 5 eV) as shown above. Instead, the difference is relatively small in the semiconductor material (<3 eV) to allow electrons to jump into the conduction band where to get additional energy.

Radiant energy entering the semiconductor material is absorbed by the material so that some electrons can move from the valence band to the conduction band. When in between the two ends of the semiconductor materials are a potential difference, there will be an electric current flow. So in this detector, the radiation energy is converted into electrical energy.

The connection is made by connecting the semiconductor N-type semiconductors of the type P (PN junction). The positive pole of the external voltage is connected to the negative pole, while N-type to P type as shown in Figure 7. This causes the charge carriers are attracted to the positive (negative pole) while the negative charge carriers are attracted to the lower (positive pole), forming (depletion layer) layer charge on the connection PN empty. With the blank layer charge this then there will be no electric current. If there is ionizing radiation that enters the empty layer this charge will be formed new ions, electrons and holes, which will move to the poles of positive and negative. Additional electrons and holes is what will lead to the formation of pulses or electric current.

Because of the power or the energy required to produce these ions is lower than the ionization processes in the gas, then the number of ions produced by the same energy will be more. This is why semiconductor detectors are very meticulous in distinguishing the radiation energy about him or known to have high resolution. As an illustration, scintillation detectors for gamma radiation typically has a resolution of 50 keV, that is, the detector is able to distinguish the energy of the radiation that enters the two when both are having different radiation energies greater than 50 keV. Medium semiconductor detectors for gamma radiation typically has a resolution of 2 keV. So it looks that much more thoroughly semiconductor detectors to distinguish radiation energy.

In fact, the ability to distinguish the less energy required in use in the field, such as radiation surveys. However, for other purposes, for example to determine the type of radionuclides or to determine the type and grade of material, this capability is absolutely necessary.

The weakness of the semiconductor detector is more expensive, its use should be very careful because it is easily damaged and some types of semiconductor detectors must be cooled to the temperature of liquid nitrogen dewar necessitating large enough.

Excellence - Weakness Detector

From the discussion above shows that each of the radiation is converted into an electrical pulse with a height proportional to the energy of radiation. It is a phenomenon that is ideal because it is in fact not the case. There are several characteristics that distinguish one type of detector with other detectors are efficiency, speed and resolution.

The efficiency of the detector is a value that indicates the ratio between the number of pulses of electricity generated to the amount of radiation detector receives. Detector efficiency value is determined by the geometry and density of the detector material. The geometry will determine the amount of radiation that can be 'captured' so that the surface area of ​​the detector, the higher the efficiency. While the density of the material affects the amount of radiation detectors that can interact to produce an electrical signal. Materials that have a density detector closer will have a higher efficiency as more radiation interacts with the material.

Speed ​​detector indicates the time interval between the arrival of the radiation and the formation of an electrical pulse. Interact with the radiation detector speed also affect the measurement because if the detector response is not fast enough, while the intensity of the radiation is so high it will be a lot of radiation that are not measurable despite the detector.

Detector resolution is the ability of the detector to distinguish between adjacent radiation energy. A detector is expected to have a very small resolution (high resolution) so as to distinguish accurately the radiation energy. Resolution of the detector caused by the statistics of events that occur in the process of conversion of radiation energy, noise from electronic circuits, as well as the instability of the measurement conditions.

Another aspect to be considered is the construction of the detector because of the complicated construction or design of the detector will be more easily damaged and usually also more expensive.

The following table shows the characteristics of several types of detectors are generally based on several considerations above.

Selection of detector should consider the advantages and disadvantages as well as the specifications table above. For example, the detector used in portable measurement tool (easy to carry) is a best gas field detector, the detector used in measuring instruments for natural radiation (very low intensity) is preferably scintillation detector, while the detectors in spectroscopy systems for materials should analyze semiconductor detector .

Dozen things parents can do to solve the preschool whimper

12 things parents can do to solve the preschool whimper :

1. Perform introspection.
Parents reflect on what he had done in assisting the child to know his world, already tepatkah or missing. Remember, parenting is an example / model closest to the child.

2. Spend time with children.
Actually, not the length of time together, but more on the quality of care you provide. Although only briefly but if sincere, it's better than the old but memorable imposed. If you are really tired and need to rest a little, well frankly tell the child, "Honey, Mama was so tired. Mama a quick break ya, later that night we play together." But remember, the promise must be kept. Once broken, the child would be difficult to believe with you.

3. Give understanding.
Place the child as a partner who can be consulted. Use language that is simple and easy to understand children. During the discussion, ask what his hopes of children. If you need to make a deal bersama.Misal, "Mom should not work, but on holidays, when Mama specially given to Brother." Thus the child continues to feel loved and appreciated.

4. Teach your child to express feelings in a positive way.
Keterampila Train a child in speech, so in the end the child can express what she feels better. Although children may not understand the feelings, you should still be done. Melati child expresses feelings from an early age will help children to be more assertive later.

5. Encourage children to talk or discussion.
Encourage children to talk when the whining / crying has subsided or are relaxed. Kala talk or discussion, use simple language and easy to understand. Reveal what is your desire. For example, "If Big Brother wants something, to say yes, not by whining. Nah, brother wants what? Come on, talking to Mama. If sister cry, Mama know how."

6. Teach children to resist the urge.
Children should know, not all wishes can be fulfilled. You'd better come clean, why can not fulfill her desire.

7. Pay attention to each child demonstrated good behavior.
Praise when he was not fussy or when he spoke well and express that you are happy. That way kids learned that good behavior endeared people around him. He also knows, to get the attention can be done in a better way, not with a whimper.

8. Ignore the bad behavior of children.
Ignoring a child who was crying / fussing also required. Here children learn, by whining or crying, he would not gain anything. Later when her tears had subsided, only you go and ask for whining. If you are too hebih or rush to pay attention, the child will learn that crying is a way to get prompt attention from people around.

9. Be firm and consistent.
When children want something and you do not allow, then Hold on, even if the child began to cry and whine. Because, once you are no firm or consistent, the child will learn that whining is the way lo get what you want. So, when children behave negatively, never hooked. After a long time the child will learn that his way is not going to work "steal" the attention of parents. For this to be effective should be done by anyone who is in the immediate neighborhood, both caregivers, grandparents and uncle-aunt, and other family members.

10. Divert attention.
When children whine, you could also persuade him to do other activities that attract attention / interest, such as reading a book, looking at the plants in the garden, playing in the yard. Sure, in a way that is proportional to persuade, not excessive.

11. No label.
Label a child with the words "sissy" does not necessarily make children so whiny. On the contrary, often labeled, children become increasingly lazy to change his behavior. He'll think, "What changed so baseball crybaby? I've been labeled a whiny child, too!" So, avoid the label. Better, change the child's behavior in a positive direction.

12. Avoid violence.
Both physical abuse (hitting) and nonphysical (scold, berate) should be avoided, because it is not solve the problem but it adds to the problem. Children are beaten not necessarily be whining subsides, usually even harder. Not a deterrent effect but the lessons learned that can be passed to solve the problem of violence. Remember, kids are great imitator. Whatever is done will be a model for her parents.

Safe Safety Search For Your Kids and More Internet Safety Tips

Using the safe browsing feature above ensures that Google SafeSearch is always "on". There are 3 levels of safe search filtering: Off (no filtering), Moderate (filters images only), and Strict Filtering (filters both text & images).

When conducting searches apart from this site on Google's main page, check your computer settings.

To implement SafeSearch on every computer in your school, simply have all students conduct Google Internet Searches from SafeSearchKids.com

Internet Safety Tips for Kids - Safer Search at Home and at School!

• Implement the use of Google SafeSearch by bookmarking this page here for your kids to use whenever they search online. Using this website ensures that Google SafeSearch is always turned on and always set to the most strict filtering setting.
• If your child is conducting searches on Google's main site at google.com, make sure your search settings are set to "strict filtering" at http://www.google.com/preferences.
• Do not replace parental or teacher supervision of computer use at home or at school with this safe search engine or any other. No search filtering software or tool is perfect.
• A good rule of thumb is to not allow internet use when a child is home alone without proper supervision, even with this Google for Kids search engine.
• Keep your computer in an open area. If your computer is in a home office, make a rule that doors are always left open when online.  Learn about YouTube parental controls.
• It's not a good idea to allow computers or laptops in your kids bedrooms, even while using the free internet filter, unless they are close to the main area of the house such as the kitchen or living room with doors left open.
• Be careful of allowing your kids to search for images online.  Use Googe Safe Image Search for added protection.
• Do not allow internet use after you've gone to bed at night no matter how good your computer security software is or how confident you are in kids search engines.
• Learn how to turn on safe search for times when your children are not using this website to conduct their searches.
• Consider installing a safe browser for kids or a complete security program such as Safe Eyes providing anti-virus protection as well as internet filtering.
• Do not allow file sharing programs to be installed on your computer. Only use safe and secure music download programs from trusted sources on the internet. Learn more about safe music downloading.
• If your child is searching for videos on YouTube, learn how you can activate YouTube parental controls.
• Have an open conversation with your kids about safe browsing and computer use. With freedom comes responsibility.
• Report inappropriate website that appear in our search results to create the safest search engine possible.

Internet Security Software Solutions - Internet Safety for Kids!
This site offers two computer security solutions to assist in kids internet safety on the internet, whether at home or in schools. The goal is ensure internet security for kids as well as computer security on or offline. We understand computer security is a top priority for children and teens alike.

1. The first solution is safe browsing implementing the use of Google SafeSearch for Kids. Simply use the search box above where safe search is always turned on, or click here for our secure safe search page with less graphics. Bookmark google safe search on your child's computer at home or at school.
2. The second way to protect your kids online is family internet filtering. Implment the use of Internet Security Software which blocks mature websites. For something more simple, we recommend KIDO'Z - the safe browser for kids.  KIDO'Z includes pre-loaded safe websites with the ability for parents to add additional favorites.

Safety Zone and Warning : A Dangerous Form Of Shock Theraphy-Seofaty.com

JAKARTA, Indonesia—Indonesian officials are scrambling to find a solution to the latest dangerous trend in Jakarta: people who roam the city's railway tracks looking for free "electric therapy."

As many as several dozen people per day intentionally try to electrocute themselves along the rails, according to local media reports, because they believe it can cure all kinds of diseases, from diabetes to high-blood pressure to insomnia. When trains approach, people briefly step aside but rush back quickly into a sleeping position on the tracks to feel electrical currents they believe will cure their ailments.

Residents say the unorthodox—and dangerous—practice started with a local rumor about a man who tried to kill himself by lying on the tracks. He was fed up after suffering paralysis from a stroke and medical treatment failed to cure his symptoms. He allegedly decided that being crushed by a train would be better than continuing his misery. But while lying on the tracks, he suddenly felt cured, according to the hearsay. It's unclear whether any elements of the story were true.

Dozens of Indonesians intentionally electrocute themselves on rail tracks every day, local media reports say.

As word of the supposed miracle spread, train tracks in slum areas in northern Jakarta became trendy as impromptu clinics. Until recently, more than 50 people would show up at the city's Rawa Buaya tracks every day. The numbers have dropped recently, since police and the state-run railroad erected a warning sign, but some people still come, convinced the tracks can cure them.

There is no medical or scientific evidence to support the treatment, says Murti Utami, a spokeswoman for Indonesia's Health Ministry. Officials have forbidden people to enter the site and threatened penalties of up to three months in prison or fines of $1,800, but it is difficult to police train tracks in Jakarta, which stretch out in all directions across the city, often with people living bunched up alongside.

"We encourage these people to seek professional medical help," Ms. Utami said. Indonesia offers free health care for its citizens, so anyone in need should go to a government clinic, she said.

However, Indonesians have long complained about the quality of care in government-run clinics, which they say are under-funded and crowded. Like many other developing countries, Indonesia continues to have high rates of preventable disease such as dengue and tuberculosis. Indonesian health standards in some instances lag behind neighboring countries, with high maternal mortality, according to the World Health Organization. Many people can't afford more sophisticated medical care than is available in government clinics.

  Moreover, Indonesians often flock to quacks and quirky cures. In February, four people died in a stampede when thousands of people sought to meet a boy shaman called Ponari—believed to be in possession of a special healing stone—after he was struck by lightning (he survived).

The 12-year-old boy rose to fame after he began practicing as a child healer with what many believe were supernatural powers capable of curing any illness. Thousands flocked to his home in Kedungsari village, in Jombang, East Java. His healing powers were supposedly delivered by dipping the stone into water, then rubbing it against ailing body parts. People collected water from his shower in the hopes of obtaining a cure for their illnesses, even though there was no medical explanation for the treatment. Many patients have claimed to be cured by the practice, however.

Indeed, some Indonesians put more trust in their faith healers and herbal-medicine doctors than in Western medicine. Indonesian officials believe education would help overcome the distrust of Western medical practices, Ms. Utami said.

Goggle safety Education : Safety Device / How To select Gas Detectors / Safety Goggles/ safety

Gas detectors have been around for a long time, starting with that infamous methane sniffing canary, which sadly was a one-shot device, which when subjected to methane, tended to die rather quickly with no audio and visual alarm capabilities other than a slight cheep and a total lack of motion. Fortunately technology has advanced significantly and we find ourselves at this point in time with some very sophisticated electronic equipment. But even the most sophisticated technology is useless if the sensors used are unable to detect the gases present. The three main atmospheric hazards that you test for prior to and throughout a confined space entry are:

Combustibles (Flammables)
Eg: Methane

• Propane
• Gasoline
• Various other site-specific hydrocarbons (specific to your industry)

Oxygen – Deficiency and enrichment

Toxics
Eg: Hydrogen Sulfide

• Carbon Monoxide
• Toxic Hydrocarbons
• Various other site-specific toxics (specific to your industry)

Depending on its sensor configuration, proper gas detection equipment can help identify the hazard
and protect your workers. Selecting a gas detector should be based on the hazard faced. Unfortunately far too many purchasers make one of the largest and most crucial single equipment expenditures without really understanding what they are buying. Sensors and their capabilities are the single most important factor when choosing a gas detector, yet more often than not, decisions are based on size,
price, bells and whistles and other such features that have nothing to do with the instrument’s detecting abilities. Gas detectors come in a variety of sizes, shapes, colours and sensor configurations. For confined space work, it is necessary to monitor for oxygen deficiency/enrichment, combustible gases and toxics. Therefore an instrument capable of dealing with these three hazards is necessary.

SENSOR TECHNOLOGY
Combustible Gas Sensors
a) Catalytic Combustible Gas Sensors.
These sensors look for explosive atmospheres. They detect combustible gases by causing an actual
combustion of gases within the sensor chamber. Catalytic sensors offer good linearity, and can react to most combustible gases. However, as resistance change to %LEL is quite small, they work better in concentrations between 1,000 and 50,000 PPM. They do not measure trace amounts of gas (under 200 PPM) and therefore are of no use in determining toxic levels. The disadvantages are:

• They must have a minimum of 14% oxygen content in the air to work accurately the sensor can be damaged by lead or silicone or other catalytic poisons
• the readings can be affected by humidity and water vapour condensation they respond poorly to low energy hydrocarbons such as oil vapours, kerosene, diesel fuel and commercial
• jet fuels
• they tend to loose their linearity after a year or so
• they are not recommended for use in an acetylene atmosphere

The flame arrestor will prevent ignition of most gases except acetylene outside the sensor. It is extremely important to check the approvals for which type of hazardous locations the detector can function in. Most portable gas detectors today will be certified for service is Class I, Div I, Group ABCD atmospheres.

b) Metallic Oxide Semiconductor (MOS) Combustible Gas Sensor MOS or “Solid State” Combustible Gas Sensors have been around for years. This sensor has a long operation life (3 to 5 years), is very rugged and will recover better from high concentrations of a gas that could damage other types of sensors. There are also disadvantages:

• MOS sensors also require oxygen to work accurately, although not as much as the catalytic
• some sensor’s heating elements have a high demand for power which requires larger battery packs
• the readings can be affected by humidity and water vapour condensation
• the MOS sensor may respond to many VOCs, HFCs and solvents, but is not specific to any single compound.

c) Infra-Red Combustible Sensors
Recently Infra-Red Sensors have begun appearing in some instruments. They work well in low oxygen levels or acetylene atmospheres; however, they are quite expensive. These sensors work by reflecting light off a mirror and measuring the amount of light adsorbed during refraction. Infrared sensors typically require a constant flow across the sensing assembly and may be slow to clear from alarm. They are unable to detect hydrogen. An Infra-Red sensor calibrated for a simple hydrocarbon such as Methane or Ethane will not be accurate for vapour of higher molecular weight hydrocarbons, solvents or fuels.

Toxic Sensors
a) Electrochemical (Wet Chem) Toxic Sensors
These sensors react to a specific chemical (substance). Chemically specific sensors are available for up to 30 different gases including chlorine, ammonia, carbon monoxide, carbon dioxide, nitrogen dioxide, nitric oxide, hydrogen cyanide, hydrogen sulfide and sulfur dioxide. The manufacturer’s technical information will indicate what sensors are available for their unit.

4 SENSOR PORTABLE
COMB, H2S, CO, O2
These sensors have very good linearity, which makes them very accurate for the substance they will react to. They can measure either large or small quantities and these sensors have a typical life span  of approximately 1 year for many toxic gases and up to two years for hydrogen sulfide and carbon monoxide. As with all sensors, Wet Chem sensors have their limitations. The electrolytic fluid can freeze when left in environments having temperatures lower than 0 degrees C. Some chemical sensors may be adversely affected by altitude as they may be pressure sensitive. Abnormal readings are another issue with regards to Wet Chem sensors. Abnormal readings are generally readings that don’t make sense. For instance you are working in a sanitary sewer and your instrument is showing a CO reading of 300 PPM (current TWA in Ontario is 35 PPM) and a low reading (below the TWA of 10 PPM) of hydrogen sulfide. What you likely have is an interference from the hydrogen sulfide. Some electrochemical carbon monoxide sensors are subject to interference from low levels of  hydrogen sulfide. The knowledge that carbon monoxide is not a common occurrence in sanitary sewer applications (whereas hydrogen sulfide is) would lead you to consider that you are probably having an interference problem. In some instances, oxidizers like chlorine, chlorine dioxide and ozone can cause opposite readings on such toxic sensors such as carbon monoxide and hydrogen sulfide. Awareness of the hazards in your workplace, some basic understanding of chemistry, knowing what interfering gases adversely affect your unit and strict testing protocols will minimize this problem.


b) Metallic Oxide Semiconductor (MOS) Toxic Broad Range Gas Sensors
There are a number of different MOS sensors on the market and one has been developed for detecting toxic gases. Its make-up and operation is similar to the one used for the detection of combustible gases. However, the MOS broad range toxic sensor is capable of reacting to low PPM levels of wide range of toxic gases including carbon monoxide, hydrogen sulfide, ammonia, styrene, toluene, gasoline and many other hydrocarbons and solvents. MOS sensors cannot detect carbon dioxide or sulfur dioxide. The sensor is incapable of telling you what gas you have encountered or the concentration, only that the atmosphere may be hazardous to your health.

C) Photo Ionization Detectors (PID’s)
Industrial Hygienists, Safety and Environmental professionals and others have used Photo ionization sensor technology for evaluating atmospheric hazards in the workplace since the 1960’s. Life expectancy of these sensors is 1-3 years and costs range between $300 and $1400 for lamp replacement. They are usually too costly to use in a multi-sensor instrument. Oxygen Sensors
Oxygen sensors are the only true chemically-specific sensors. They are similar to the electrochemical (Wet Chem) sensors described previously. They are also susceptible to freezing, are sometimes  affected by altitude and have a nominal operational life of one to two years. Never use an oxygen sensor to detect toxic gases. It is true that a toxic gas will displace the oxygen in a confined space. However, it takes 60,000 PPM of any gas to lower the oxygen from 20.9% (normal) to 19.5% (alarm point). More importantly, 60,000 PPM of any toxic gas will kill you.

DESIGNING A GAS DETECTOR
Let’s build a gas detector for confined space work. To start out it will require a combustible sensor. We previously described the three types of combustible sensors available and their features. However, for confined space work, any of the three technologies will provide adequate protection. Secondly, we need an oxygen sensor to detect both oxygen enrichment and deficiency. There are several manufacturers of oxygen sensors and while they may all look different, they are essentially the same technology and will work well. To complete this instrument we will require a toxic sensor(s). The key to safe confined space gas detection lies in these toxic sensors. There are two main sensor types used in multi-sensor instrmuments electrochemical (Wet Chem) and Broad Range (Solid State MOS).
To select the correct toxic sensor we need to evaluate our confined spaces. If your area of work is an industrial site, where the toxic gases are known or can be controlled, then a chemically specific toxic sensor can be chosen (providing a sensor exists for that gas hazard). Manufacturers produce gas detectors that are capable of supporting one or two of these chemically specific sensors. Some instruments are available with a range of plug-in sensors that can be changed in the field without fuss or calibration. Other instruments must be ordered with the specific toxic sensor(s) you require. However, there is a limit to the sensors available and, if toxic hydrocarbons or solvents are a concern (common to municipal water and waste water systems as well as industrial applications), then the broad range (MOS) type may be your best bet. If you are in an area where the toxics are unknown or cannot be controlled, such as storm and sanitary sewers, pumping stations, waste treatment plants, industrial sites with toxic hydrocarbons and the like, then the broad range (MOS) type is your best solution. Unlike the chemically specific electrochemical sensors, these sensors cannot differentiate one toxic gas from another but they will tell you whether it is safe to enter or it is time to get out. The broad range sensors have their limitations as well and cannot detect any of the dioxides, i.e.:
carbon dioxide, sulphur dioxide. It must be noted that a gas detector with a combustible sensor
will not protect you from toxic levels of hydrocarbons. A classic example is gasoline. Gasoline used to have a TWA of 900 PPM. It is now considered a carcinogen. A combustible gas detector, calibrated to methane, will not alarm on gasoline until around 50% of the LEL or 5000 to 7000 PPM. This is well in excess of the old TWA and is certainly an
even bigger problem now that it is rated as a carcinogen. Regardless of its cancer causing issues, this level can cause a worker to be rendered unconscious, potentially causing death through drowning or falling. The only toxic sensors capable of detecting these low levels of hydrocarbons are the broad  range.


SAMPLING METHODS
In confined space testing it is important that the operator know how the sensor comes in contact (operation) with the atmosphere. There are three primary means of exposing the sensor to the  atmospheresample draw, diffusion and a detachable remote diffusion sensor assembly. There are strengths and weakness in all systems. Selection should be based upon need, not availability. Sample Draw The most common form of sampling a confined space is the sample draw method. The  advantage of this method is that any monitoring is performed outside the space. With a sample draw system, a pump moves the sample from the atmosphere and draws it through a hollow tube to the sensor. The pump can either be a “bulb” hand aspirator which requires squeezing or an internal motorized sample pump. Drawing the sample to the detector protects the tester by eliminating the need to enter the space and limits any movement of the door/cover to the space that may create a spark, which could ignite flammable gases that may collect around the entry point. For these reasons, the sample draw method is recommended when conducting your pre-entry test. The primary  disadvantage of this method is sample dilution. The tube leaking or using a tube over 12’ in length may reduce the concentration of some contaminant to the point where the readings presented are inaccurate. Other problems may include leaking pumps, cumbersome sample lines, and in some environments, the sample line may plug due to sludge, dirt or condensate icing. A disadvantage of the manual sample draw methods is the effort involved moving the air sample along the tube to the sensor. A general rule of thumb is that it takes 3 pump strokes to move the sample 1 foot. If your line is 12’, it will take 36 pump strokes to get the sample to the sensor, then the sampling must continue for up to 3 minutes to ensure a proper undiluted sample. If you are using a bulb hand aspirator strong
wrists are both a requirement and the end result of a lot of entries.


Sensor Operation

5 SENSOR PORTABLE
O2, COMB, H2S, CO, MOS TOXIC
Most gas detector sensors operate by diffusion. Diffusion works by air being absorbed into the sensor
cell. Electronic gas detectors rely heavily on diffusion sampling. The atmosphere must be brought to the gas sensors by the aforementioned sample draw (aspiration) or by lowering the gas detector into atmosphere. Some manufacturers offer a detachable remote sensor assembly as a means of remote sampling. Advantages of this technology include the lack of pumps and moving parts, much faster response time than aspiration and wires can carry the information with no potential of diluted readings. The sample method is still diffusion but the sensors are lowered into the atmosphere to be tested. Once the atmosphere has been tested by aspiration and/or remote sensors, the gas detector can be worn by the worker for the duration. Because each sampling method has its own strengths and weaknesses, all techniques are used to monitor the atmosphere. The sample draw is used for the pre-entry test that occurs just inside the space at the doorway. (suggestion: use a 6’ or shorter tube). Diffusion sampling occurs at all other times. Regardless of sampling techniques, spaces two to three meters deep should be tested top and bottom before entering. Spaces four to five meters deep should be tested top, middle and bottom before entering. Calibration/Bump Test All portable gas detectors should be calibrated according to the manufacturers recommendations. Not calibrating or bump testing a gas detector on a regular basis is an invitation to disaster. Sensors and/or electronics can, and do fail and it is only prudent to check your instrument on a regular basis.
a) Bump Test
A bump or field test is the application of a known gas concentration in excess of the calibrated alarm
point of the instrument. When this gas is applied to the gas detector it should trip the alarm point ensuring that the instrument is functioning correctly. If it does not then it indicates that a re-calibration is necessary. Multiple gas mixtures are available that allow you to do a simultaneous Bump test with one canister of gas. It is a good policy to bump test at least once a week.
b) Calibration
Calibration should be performed as per the manufacturers recommendations. Calibration is done with
a known gas concentration that can be at the exact alarm point or at a higher concentration where the set point can be adjusted. This varies between manufacturers. If you are Bump/Field testing on a regular basis you can wait until that tests indicates a re-calibration is required. If Bump/Field test are not performed then the unit should be re-calibrated on a regular basis. Manufacturer’s recommendations vary from daily to never. Daily may not be practical and never, while time saving can be an invitation to disaster. Somewhere in between is the answer. Every three to six months is common.

DESIGN CHARACTERISTICS
The third component to consider in gas detector selection is design characteristics. Many gas detectors are sold solely upon these characteristics. The reason for this is that many gas detector manufacturers do not make their own sensors. They design and make the electronic box of the gas detector. The following characteristics should be considered after selecting the appropriate sensors:

• Construction
• Electronics
• Approvals
• Ease of use

a) Construction
Monitoring devices must be very rugged and easily carried by the workers. Even with training and the best intentions of the workers, field use does abuse the units. Drops, jolts, exposure to the elements, misuse, etc., all can shorten the life of the instrument. The case and its components must be constructed to withstand rough handling. The unit’s alarm systems, which should be both audio and visual, must be loud enough to be heard in your environment by either the attendant outside the space or the entrant(s) inside. In a perfect world, both attendant and entrant would hear the alarm. Some manufacturers have remote alarms that could enable both the attendant and entrant to simultaneously hear the alarm. The option is only worth the money spent if the remote wiring is long enough for all your spaces. Batteries are another consideration. Batteries can be either disposable or rechargeable but either type should supply enough power to last 10 to 12 hours. If the batteries cannot last the entire work period, a back up or stand by power source must be present. Batteries have all sorts of limitations. Many units have no way to determine the charge in them; cold and age decrease battery life; lead acid batteries can leak and damage your electronics; NiCad (rechargeable batteries) can develop memories and so on. Battery maintenance costs and efforts should be evaluated very carefully to ensure your system will work when required. The new nickel metal hydride rechargeable batteries appear to have cut down the memory problems found in the older NiCad rechargeable  batteries. For confined space work, gas detectors need to be portable (hand held). If the unit is  designed to be worn by the worker, it should rest on their belt, not weigh it down. In many tight spots, the worker should not wear the device as it may create a catch point. It may be advisable to have the ability to hang up the unit inside the space. Switches, buttons and knobs should be positioned or designed so that they cannot be knocked out of position, but one can still operate them with gloves on. The unit should be tamper resistant and default to an alarm mode in the event of battery or sensor failure. Gauges and/or displays should be large and easily read and understood. This means you must be able to not only see the displayed data, but also understand it. In confined spaces there are all types of lighting. Does the information show in all lighting situations? And finally, do the abbreviations make sense or do you need an explanation card on the detector? If the information cannot be understood, it may not be performing the job that it is intended to do.

b) Electronics
Information provided must be reliable and useful as life and death decisions can be made based on the data provided. The electronics’ response time, accuracy, precision, radio frequency (RF) interference, reading drift and sensitivity are all factors that can differentiate a poor purchase from a good investment.

c) Approvals*
Once a manufacturer has developed an instrument for use in a hazardous atmosphere, it should be approved by an independent laboratory for intrinsic safety. Ie: UL, FM, CSA, TUV, MET etc. Federal OSHA in the USA identifies such approval laboratories as “NRTL” (Nationally Recognized Testing Laboratories) and lists four pages of them on its website.

d) Ease of Use
One of the most important considerations after sensor evaluation and selection is the ease of use of the instrument. Is it simple to operate? Is it simple to understand? Are the buttons/switches easy to use with gloves on? Do you have to use switches or buttons to get alarm information? Will it alarm when battery/sensors fail? Most importantly, is it one switch operation?

TECHNICAL CONSIDERATIONS
RF Protection
Radio Frequency Interference (RFI) protection is the unit’s ability to protect the readings from interference caused by radio waves, pulsed power lines, transformers, and generators. RF protection is expressed in immunity to x watts of radio transmission at a specific distance. A prudent consumer should test a gas detector in and around cell phones, radios and walkie talkies before purchasing, especially if the gas detector is packaged in anything other than metal.

Response Time
4 SENSOR PORTABLE
COMB, O2 AND ANY 2 OF 13
FIELD INTERCHANGEABLE
TOXIC SENSORS

This is the time period between obtaining data from the sensors and displaying it. This time period
depends on what information is collected, the sensor response, how the unit of measurement being used (e.g. % LEL or PPM). Response time can range from several seconds for catalytic elements to minutes for some toxic sensors. Accuracy and Precision Accuracy is the relationship between the readout and the true concentration. This relationship is indicated by an error factor (indicated by “+/-“,e.g. +/- 0.5%). The lower the number, the greater the instrument’s accuracy. Precision is the number of times the accuracy would be right in any given number of tests (correct 19 times out of 20). In this case the higher the number, the greater the precision.


Sensitivity
This is the unit’s ability to accurately measure changes in concentrations. The hazards presented by
the substance being measured would determine the need for sensitivity. For instance, at present in Ontario, chlorine has a time weighted average exposure value of 1 PPM and if is IDLH at 10 PPM; therefore, any change must be noted at once. On the other hand, carbon dioxide’s TWAEV is 5000 PPM, and is IDLH at 40,000 PPM; therefore the sensitivity need not be that great.
Selectivity/Specificity This is the ability of the sensor/circuitry to respond to the desired target gas to the exclusion of other interfering gas species.


Reading Drifts
This is the movement in the instrument’s electronic readout when the atmospheric value remains the
same. Moving the instrument from one angle to another, shaking it, ambient vibrations or no apparent reason may cause the readout to change. Poor electronic circuit board design and/or age of the machine or the sensor will cause the readings to drift. Sensor or component aging causing this problem is acceptable and can be compensated for as part of the unit’s ongoing maintenance program; however, poor construction is not acceptable. Poor construction cannot be repaired and creates mistrust of the unit with those who work with it. If they do not trust the readings, they will not use it and a tragedy could easily occur. Your best protection is to contact current users of the instrument and ask about their experiences. Well we have now arrived at close to 4100 words on selecting a gas detector. If you are still awake, congratulations, because to get to this point you must have some interest in this topic not to have been bored to death. In closing I would like you to please keep in mind that portable gas detectors are available from a variety of manufacturers. They range from single electrochemical sensor instruments to very precise multiple sensor units. Do not be swayed by sophisticated technology and fancy packaging. Choose a device that meets your needs (both short term and for the next 3 to 5 years if possible). Look at all the variables from sensors to design, but always keep sensors as your number one criteria. Your employees also have to be considered in the equation. If not, a perfectly good gas detector will collect dust because they feel the damn thing isn’t any good! A well thought out purchase can save lives and prevent injuries

What I Have To Do If Lightning ?

 A house or other substantial building offers the best protection from lightning. In assessing the safety provided by a particular structure, it is more important to consider what happens if the structure gets struck by lightning, rather than whether the structure will be hit by lightning. For a shelter to provide protection from lightning, it must contain a mechanism for conducting the electrical current from the point of contact to the ground.

These mechanisms may be on the outside of the structure, may be contained within the walls of the structure, or may be a combination of the two. On the outside, lightning can travel along the outer shell of the building or may follow metal gutters and downspouts to the ground. Inside a structure, lightning can follow conductors such as the electrical wiring, plumbing, and telephone lines to the ground.

Avoid unsafe shelters

Unless specifically designed to be lightning safe, small structures do little, if anything, to protect occupants from lightning. Many small open shelters on athletic fields, golf courses, parks, roadside picnic areas, schoolyards and elsewhere are designed to protect people from rain and sun, but not lightning. A shelter that does not contain plumbing or wiring throughout, or some other mechanism for grounding from the roof to ground is not safe. Small wooden, vinyl, or metal sheds offer little or no protection from lightning and should be avoided during thunderstorms.

How lightning enters a house or building

There are three main ways lightning enters homes and buildings: (1) a direct strike, (2) through wires or pipes that extend outside the structure, and (3) through the ground. Regardless of the method of entrance, once in a structure, the lightning can travel through the electrical, phone, plumbing, and radio/television reception systems. Lightning can also travel through any metal wires or bars in concrete walls or flooring.

Stay safe while inside

Phone use is the leading cause of indoor lightning injuries in the United States. Lightning can travel long distances in both phone and electrical wires, particularly in rural areas. Stay away from windows and doors as these can provide the path for a direct strike to enter a home. Do not lie on the concrete floor of a garage as it likely contains a wire mesh. In general, basements are a safe place to go during thunderstorms.

However, there are some things to keep in mind. Avoid contact with concrete walls which may contain metal reinforcing bars. Avoid washers and dryers since they not only have contacts with the plumbing and electrical systems, but also contain an electrical path to the outside through the dryer vent.

Remember your pets

You may want to consider the safety of your family pets during thunderstorms. Dog houses are not lightning-safe. Dogs that are chained to trees or chained to wire runners can easily fall victim to a lightning strike.

Protect your personal property

Lightning also causes significant damage to personal property each year. In addition to direct strikes, lightning generates electrical surges that can damage electronic equipment some distance from the actual strike. Typical surge protectors will NOT protect equipment from a lightning strike.

To the extent possible, unplug any appliances or electronic equipment from all conductors well before a thunderstorm threatens. This includes not only the electrical system, but also the reception system. If you plan to be away from your home when thunderstorms are possible, be sure to unplug unneeded equipment before you leave.

Summary of lightning safety tips for inside the home

Avoid contact with corded phones

Avoid contact with electrical equipment or cords. If you plan to unplug any electronic equipment, do so well before the storm arrives.

Avoid contact with plumbing. Do not wash your hands, do not take a shower, do not wash dishes, and do not do laundry.

Stay away from windows and doors, and stay off porches.

Do not lie on concrete floors and do not lean against concrete walls.

Intelegent Copilot For Car : Semiautonomous system takes the wheel to keep drivers safe

Barrels and cones dot an open field in Saline, Mich., forming an obstacle course for a modified vehicle. A driver remotely steers the vehicle through the course from a nearby location as a researcher looks on. Occasionally, the researcher instructs the driver to keep the wheel straight — a trajectory that appears to put the vehicle on a collision course with a barrel. Despite the driver’s actions, the vehicle steers itself around the obstacle, transitioning control back to the driver once the danger has passed.

The key to the maneuver is a new semiautonomous safety system developed by Sterling Anderson, a PhD student in MIT’s Department of Mechanical Engineering, and Karl Iagnemma, a principal research scientist in MIT’s Robotic Mobility Group.

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The system uses an onboard camera and laser rangefinder to identify hazards in a vehicle’s environment. The team devised an algorithm to analyze the data and identify safe zones — avoiding, for example, barrels in a field, or other cars on a roadway. The system allows a driver to control the vehicle, only taking the wheel when the driver is about to exit a safe zone.

Anderson, who has been testing the system in Michigan since last September, describes it as an “intelligent co-pilot” that monitors a driver’s performance and makes behind-the-scenes adjustments to keep the vehicle from colliding with obstacles, or within a safe region of the environment, such as a lane or open area.

“The real innovation is enabling the car to share [control] with you,” Anderson says. “If you want to drive, it’ll just … make sure you don’t hit anything.”

The group presented details of the safety system recently at the Intelligent Vehicles Symposium in Spain.

Off the beaten path

Robotics research has focused in recent years on developing systems — from cars to medical equipment to industrial machinery — that can be controlled by either robots or humans. For the most part, such systems operate along preprogrammed paths.

As an example, Anderson points to the technology behind self-parking cars. To parallel park, a driver engages the technology by flipping a switch and taking his hands off the wheel. The car then parks itself, following a preplanned path based on the distance between neighboring cars.

While a planned path may work well in a parking situation, Anderson says when it comes to driving, one or even multiple paths is far too limiting.

“The problem is, humans don’t think that way,” Anderson says. “When you and I drive, [we don’t] choose just one path and obsessively follow it. Typically you and I see a lane or a parking lot, and we say, ‘Here is the field of safe travel, here’s the entire region of the roadway I can use, and I’m not going to worry about remaining on a specific line, as long as I’m safely on the roadway and I avoid collisions.’”

Anderson and Iagnemma integrated this human perspective into their robotic system. The team came up with an approach to identify safe zones, or “homotopies,” rather than specific paths of travel. Instead of mapping out individual paths along a roadway, the researchers divided a vehicle’s environment into triangles, with certain triangle edges representing an obstacle or a lane’s boundary.

The researchers devised an algorithm that “constrains” obstacle-abutting edges, allowing a driver to navigate across any triangle edge except those that are constrained. If a driver is in danger of crossing a constrained edge — for instance, if he’s fallen asleep at the wheel and is about to run into a barrier or obstacle — the system takes over, steering the car back into the safe zone.

Building trust

So far, the team has run more than 1,200 trials of the system, with few collisions; most of these occurred when glitches in the vehicle’s camera failed to identify an obstacle. For the most part, the system has successfully helped drivers avoid collisions.

Benjamin Saltsman, manager of intelligent truck vehicle technology and innovation at Eaton Corp., says the system has several advantages over fully autonomous variants such as the self-driving cars developed by Google and Ford. Such systems, he says, are loaded with expensive sensors, and require vast amounts of computation to plan out safe routes.

"The implications of [Anderson's] system is it makes it lighter in terms of sensors and computational requirements than what a fully autonomous vehicle would require," says Saltsman, who was not involved in the research. "This simplification makes it a lot less costly, and closer in terms of potential implementation."

In experiments, Anderson has also observed an interesting human response: Those who trust the system tend to perform better than those who don’t. For instance, when asked to hold the wheel straight, even in the face of a possible collision, drivers who trusted the system drove through the course more quickly and confidently than those who were wary of the system.

And what would the system feel like for someone who is unaware that it’s activated? “You would likely just think you’re a talented driver,” Anderson says. “You’d say, ‘Hey, I pulled this off,’ and you wouldn’t know that the car is changing things behind the scenes to make sure the vehicle remains safe, even if your inputs are not.”

He acknowledges that this isn’t necessarily a good thing, particularly for people just learning to drive; beginners may end up thinking they are better drivers than they actually are. Without negative feedback, these drivers can actually become less skilled and more dependent on assistance over time. On the other hand, Anderson says expert drivers may feel hemmed in by the safety system. He and Iagnemma are now exploring ways to tailor the system to various levels of driving experience.

The team is also hoping to pare down the system to identify obstacles using a single cellphone. “You could stick your cellphone on the dashboard, and it would use the camera, accelerometers and gyro to provide the feedback needed by the system,” Anderson says. “I think we’ll find better ways of doing it that will be simpler, cheaper and allow more users access to the technology.”

This research was supported by the United States Army Research Office and the Defense Advanced Research Projects Agency. The experimental platform was developed in collaboration with Quantum Signal LLC with assistance from James Walker, Steven Peters and Sisir Karumanchi.

Source : Jennifer, MIT News Office

Heavy Equipment Safety : Toolbox Meeting

Company Name __________________________ Job Name __________________________ Date________

HEAVY EQUIPMENT SAFETY

Operation of heavy equipment such as excavators, loaders, graders, rollers, and bulldozers, should always be done by highly skilled operators who have demonstrated the ability and necessary skills to operate safely. Ground-based workers should be trained in how to work safely around the equipment, and how to stay clear. Unsafe practices by either the operator or those around the equipment can create very dangerous situations. Serious injuries can occur if the equipment strikes a worker, or if the equipment is rolled over.

Here are a few common safety rules for operators and ground based workers to consider:

1) Good communication is essential. A standardized set of hand signals should be used by the operator and signal person. Operators should always know exactly where all ground based workers are located, and the wearing of high visibility vests will help the operator to locate them quickly. The equipment should have a back up warning alarm that can be heard by all nearby workers. Two-way radios are also valuable communication tools.

2) Heavy equipment must have a rollover protective structure (ROPS) meeting OSHA requirements. The ROPS is designed to protect the operator if the machine tips over. A seat belt must be worn so that the operator will not be thrown out of the seat during a rollover or upset situation. If working on slopes, try to avoid moving across the face of the slope. Try to operate up and down the slope face if possible. Use extreme caution when operating near open excavations.

3) Wear hearing protection when required. If it has been determined that noise levels around the equipment could potentially cause hearing loss, always use protective plugs or muffs when working on or around the equipment.

4) Never jump onto or off the equipment. Operators should always use the three-point contact rule when climbing onto or off heavy equipment. The three-point rule means having both feet and one hand, or one foot and both hands in contact with the ladder access at all times.

5) Inspect and service the equipment regularly. Complete equipment service in accordance with the manufacturer's recommendation. Periodic safety inspections on all components of the equipment should be done regularly by qualified personnel. Inspect the steering system and brake systems carefully. A pre-shift walk around inspection by the operator is highly recommended.

Injury accidents involving heavy equipment on construction sites have a higher probability of resulting in a fatality than many other types of accidents. It is critical to follow all of your company's safety rules and procedures when operating or working around heavy equipment.

Safety Recommendations:__________________________________________________________________________________

Job Specific Topics:_______________________________________________________________________________________

M.S.D.S Reviewed:_______________________________________________________________________________________

Attended By:

Safety Biker : When To Replace A Helmet / Safety Tips 007

Summary:

• Did you crash it? Replace immediately. 
• Did you drop it hard enough to crack the foam? 
• Replace. Is it from the 1970's? Replace. Is the outside just foam or cloth instead of plastic? Replace.
• Does it lack a CPSC, ASTM or Snell sticker inside? Replace. 
• Can you not adjust it to fit correctly? Replace!!

Did you crash in it?
For starters, most people are aware that you must replace a helmet after any crash where your head hit. The foam part of a helmet is made for one-time use, and after crushing once it is no longer as protective as it was, even if it still looks intact. Bear in mind that if the helmet did its job most people would tell you that they did not even hit their head, or did not hit their head that hard. And the thin shells on most helmets now tend to hide any dents in the foam. But if you can see marks on the shell or measure any foam crush at all, replace the helmet. (Helmets made of EPP foam do recover, but there are few EPP helmets on the market. Yours is EPS or EPU unless otherwise labeled.)

You can also crack the helmet foam or damage it by dropping the helmet on a hard surface. The cracks may be small and hard to see, so you need to look carefully. Cracks in the foam always require replacement of the helmet.

You may be reluctant to replace a helmet that looks almost as good as new, but if you did hit, you don't want to take chances on where you will hit next time. If the foam is cracked under the thin shell, it will be more likely to fly apart in your next crash. Many manufacturers will replace crashed helmets for a nominal fee, and most will also inspect crashed helmets to see if they need replacement. Call them if you are in doubt. For contact info check our list of manufacturers. (You can also ask them if they think the advice on this page is valid!} Is it from the 70's?

If you still have a helmet from the 70's without a styrofoam liner, replace it immediately. That would include the Skidlid (with spongy foam), 1970's Pro-tec (spongy foam), Brancale (no foam) and all leather "hairnets." They just did not have the protection of helmets made after 1984 when the ANSI standard swept the junk off the market.

The better 1970's helmets were reasonably good ones, but were not quite up to current standards. It is probably time to replace that old Bell Biker, Bailen, MSR, Supergo or similar model from the 70's or early 80's. (We have a page up on replacing the Bell Biker.) The hard shells were great, but the foam liners were not thick enough to meet today's ASTM or Snell standard. The Bell V-1 Pro was designed to today's standards, but the foam is very stiff, and if you are over 65 you probably should replace that too. If you have one of the 1980's all-foam helmets with perhaps a cloth cover, we would recommend replacing that one. Lab tests showed some years ago that bare foam doesn't skid well on pavement, and could jerk your neck in a crash. The cloth doesn't help much. In addition, some of them had no internal reinforcing, and they tend to break up in a crash. That's not serious if you just fall, but if you are hit by a car the helmet can fly apart in the initial contact and leave you bare-headed for the crack on the pavement.

Is it newer? With what standards sticker inside?

Newer helmets from the late 1980's and the 90's may or may not need replacement. First look to see what standards sticker is inside. If it's ASTM or Snell, the helmet was designed to meet today's standards for impact protection, and you may even find that Consumer Reports tested it in one of their articles. Most manufacturers now recommend that helmets be replaced after five years, but some of that may be just marketing. (Bell now recommends every three years, which seems to us too short. They base it partially on updating your helmet technology, but they have not been improving their helmets that much over three year periods, and we consider some of their helmets since the late 1990's to be a step backwards, so we would take that with a grain of salt.) Deterioration depends on usage, care, and abuse. But if you ride thousands of miles every year, five years may be a realistic estimate of helmet life. And helmets have actually been improving enough over time to make it a reasonable bet that you can find a better one than you did five years ago. It may fit better, look better, and in some cases may even be more protective. For an alternate view that agrees with the manufacturers, check out the helmet FAQ of the Snell Foundation. Snell knows a lot about helmets and their views on this subject should not be dismissed lightly, even though we disagree with them.
Occasionally somebody spreads rumors that sweat and ultraviolet (UV) exposure will cause your helmet to degrade. Sweat will not do that. The standards do not permit manufacturers to make a helmet that degrades from sweat, and the EPS, EPP or EPU foam is remarkably unaffected by salt water. Your helmet will get a terminal case of grunge before it dies of sweat. Sunlight can affect the strength of the shell material, though. Since helmets spend a lot of time in the sun, manufacturers usually put UV inhibitors in the plastic for their shells that control UV degradation. If your helmet is fading or showing small cracks around the vents, the UV inhibitors may be failing, so you probably should replace it. Chances are it has seen an awful lot of sun to have that happen. Otherwise, try another brand next time and let us know what brand faded on you.
At least one shop told a customer that the EPS in his three year old helmet was now "dried out." Other sales people refer to "outgassing" and say that the foam loses gas and impact performance is affected. Still others claim that helmets lose a percentage of their effectiveness each year, with the percentage growing with age. All of that is nothing but marketing hype to sell a replacement helmet before you need it. There is some loss of aromatics in the first hours and days after molding, and helmet designers take account of that for standards testing. But after that the foam stabilizes and does not change for many years, unless the EPS is placed in an oven for some period of time and baked. The interior of your car, for example, will not do that, based on helmets we have seen and at least one lab crash test of a helmet always kept in a car in Virginia over many summers. Helmet shells can be affected by car heat, but not the foam. The Snell Memorial Foundation has tested motorcycle helmets held in storage for more than 20 years and found that they still meet the original standard. EPS is a long-lived material little affected by normal environmental factors. Unless you mistreat it we would not expect it to "dry out" enough to alter its performance for many years.

An honest manufacturer: MET

The Italian company MET says in their 2010 catalog: "We are often asked 'For how long is a helmet safe?', or 'how often should I replace my helmet?”' Until now it has been difficult to find any reliable figures to help answer these queries. MET have now developed a series of tests which are conducted on aged helmets to determine a 'best before' date (unless the helmet is involved in an accident. In that case it should be replaced immediately.). The results indicate that, if used properly accordingly to our owner manual, our helmets will still do their job up to eight years after they have been made. Not only is that good news for the customer, it’s great news for the environment!"

We applaud MET for undertaking an actual testing program on helmet life and for making that statement. We regard it as a triumph of integrity over marketing. MET's helmets are made with industry standard shells and liners, so there is no reason we can see that their recommendation should not be good for many other helmet brands as well. If another manufacturer comes up with a testing program that shows earlier deterioration in the protection from their products we will review this page.

In sum, we don't find the case for replacing a helmet that meets the ASTM or Snell standards that compelling if the helmet is still in good shape and fits you well. Are you using it for non-bicycle activities?

Since 2003 helmets have been available that are actually certified to skateboard or ski standards as well as the CPSC bicycle helmet standard. If you are using a bicycle helmet for skateboarding or any other sport where you crash regularly, see our writeup on helmets for the current season for more info on that.

Otherwise, we would recommend buying another helmet designed for the activity you are pursuing, whether or not you replace your bike helmet. We have more on that subject on our page on other helmets. Note that most "skate-style" helmets currently on the market are actually bicycle helmets certified only to the CPSC bicycle helmet standard. They have CPSC stickers inside, but no ASTM Skateboard standard sticker. Do you still like wearing it?

Your helmet is of course a piece of wearing apparel as well as a safety appliance. If you consider yourself a stylish rider and your helmet is not as spiffy as the new ones, go for it. There is nothing wrong with wanting to look good, and if you do, fashion is a valid reason to replace a helmet.
Is it a better helmet than the ones available today?

As new styles have become more "squared-off" and designers have begun adding unnecessary ridges and projections that may increase the sliding resistance of a helmet shell, there is good reason to stay with one of the more rounded designs of the early to mid 90's. Those round, smooth shells like the original Bell Image that Consumer Reports rated highly in 1993 are more optimal for crashing than some of the newer designs. So think twice about "moving up," and look for a rounded, smooth-shelled design when you do. We have a lot of info on the new ones up on our page on helmets for the current season.
Inspecting a Helmet
We have a page up with step by step instructions on how to inspect a helmet.

Safety Bicycle Helmet Inspection For Biker 03

Inspection

You need to look at the helmet's main elements: Outside Shell

The exterior plastic of a helmet is important to hold it together in a crash. Look first for cracks or abrasion on the surface that show evidence of an impact. Even if you think the helmet has never been impacted, look carefully. Many riders don't know they hit their head. Small cracks around the edges or anywhere else on the shell indicate aging and a need to replace.

Press carefully all over the helmet to see if you get a "beer can" effect where the shell can be pushed in and it pops back. Most cheap helmets show some of that when new, but that should be all over the helmet, and very little. If the shell dents more than a little bit, that indicates crushed foam underneath, and a need to replace. If there is crushed foam you would usually see abrasion of the shell where it indents. Note that more expensive helmets that are molded in the shell should have no beer can effect whatsoever. With those helmets any flat spot on helmet surfaces that were formerly curved would indicate damage.

Check the shell color for fading. The helmet below was ridden across the US by Brian Hanson. It was vibrant yellow when he started. With constant sun exposure it faded badly, probably from lack of sufficient UV inhibitors in the plastic. If your helmet fades, the plastic has probably become brittle, and it should be replaced. Brian replaced his.

Liner

Remove the fitting pads if they come out, and inspect the styrofoam liner carefully for any signs of cracks or compressed foam. If in doubt about a spot on the helmet, measure the foam thickness and that of an identical spot on the other side, or if you have another helmet of the same model and size, use that. If you discover any cracked or crushed foam, replace the helmet. Remember that EPS liners do recover some of the crushed thickness, but the foam that was compressed will not perform well in the next hit. Even if you find no damage, if you know the helmet has taken an impact you should replace it. The damage can be difficult to identify even with careful measuring.

If you have one of the few bike helmets with an EPP (Expanded PolyPropylene) or other multi-impact liner, do the inspection as described above anyway. EPP recovers, but not 100%. In time if you crash more than once you will find foam damage and need to replace your helmet.

Buckle and Strap

Check the straps on the helmet for signs of wear, and replace if they seem worn, faded or any of the stitching is beginning to fail. Salt accumulations should be washed out before inspection. Check the buckle and replace if you see any missing parts. The plastic blades that lock into the female side of most buckles can break. The buckle will hold together weakly with one blade, but will fail in a crash.

Rear Stabilizer

The rear stabilizer on many of today's helmets is not really part of the retention system that holds the helmet on the head, but a means of adding some stability for comfort. It should still be inspected for structural integrity and to be sure the adjustment is working. Stretching or tugging it with moderate force will usually tell you that.

Standards Sticker

Some older helmets had impact protection as good as anything on the market today. If yours has a CPSC, ASTM or Snell sticker in it and passes the other inspection points, it is probably still a good helmet. If is is older than that, it should be replaced.

More on replacement

We have a page up on when you need to replace a helmet, with more detail on what makes it necessary.

Rentals

In addition to cleaning a helmet when it is returned, the inspection steps are critical for renting. Many riders will not tell you when they crash, or will not think they hit their heads. With experience the steps above can be quickly done, but you must remember to do them each time.

Checklist

Here is the info on this page as a helmet inspection checklist. in .pdf format for printing out.

Biker Safety : Bicycle Night Visibility And Lights

The Question

>I was wondering about solutions for *BICYCLE* visibility at night.

The Response:

I have used many devices over the years, since I commuted for about 20 years and still ride a lot at night. I started with white bicycles, then tried 3M's glass bead reflective paint. It looked great under headlights but was dull otherwise. I am now using neon orange bikes, and may go to neon lime green. I think all of those approaches are improvements over a standard dark frame, since seeing a frame identifies the vehicle immediately as a bicycle, at least from the side and some other angles.

The concept you have to keep in mind is that you want to establish your identity as you catch the driver's eye so they know what you are. Motorcycle research shows that if you want to be seen on a motorcycle there is one thing that beats daytime headlights, orange vests, flags, big windshields or any other device -- be a cop! It turns out that drivers usually see a police motorcycle. We have asked motorcycle cops and they agreed, although there are exceptions. So you are not just trying to catch an eye. You are really trying to register on a driver's brain that you are a vehicle moving on the road, and establish that you are a bicycle so that the driver has some idea of what your speed and position on the roadway are likely to be. Often you are doing that in the midst of incredible urban light clutter from other vehicles, traffic signs, streetlights, commercial signage, porch lights, windows and many other sources.

For headlights I use a car light. Nothing makes a driver respond quicker, even in the midst of urban light clutter, since they are conditioned from childhood to look for oncoming cars, and at night that means they are looking for oncoming car lights. The little bike lights may be bright, but they look like a pinpoint, and can just get lost among all the other light sources in the background. Car lights have a cutoff beam that does not blind others on a trail, and puts the light on the roadway where you need it.

The nicads to run my car light were heavy and required charging every night, but they were cheap from surplus sources. For years I used D cells from power packs for an NEC 386 laptop. Then I converted to NiMH batteries, and tried using C cells due to the higher energy of NiMH cells, but went back to D cells eventually because the C's just did not seem to hold up and lost capacity. I used 11 (NiMH)or 12 (NiCad) cells rather than ten to provide extra voltage and keep the light bright. Again, the cheap NiMH D cells did not hold up that well in daily use, and I now have to charge that battery almost continuously to have it work. In the fall of 2006 I started phasing in a 5.5AH Powerizer Lithium Ion / Polymer battery that weighs 18 oz (500gr), puts out 14.7 volts for a very bright headlight and may melt down some day the way lithium cells sometimes do when cell protection circuits fail. The vendor says "for R&D use only and NOT for individual customers." I charge it in my bike parking area and use it while riding outdoors, so that's a concern but seems like a reasonable risk similar to those that laptop users are running. I am looking for one in the safer LiFePO4 chemistry that self-extinguishes if a protection circuit fails.

For tail lights I started with two leg lights, showing red to the rear and white to the front. Those have the advantage of going up and down, attracting attention and identifying the bike. But they are visible only on one side, so for a while I used two of them. I still use one sometimes as an identifier. I added yellow blinkers, starting with a 7 inch barricade light. Those are ideal for bikes, since they attract attention by the blink, have a big reflective band around them, and are identified in a car driver's mind with stationary objects on construction sites, so they grab a driver's attention. As with any blinking light, the blink saves a lot of electrical power, since the light is mostly off. The fresnel lens is very efficient, and the bulbs are designed to resist tremendous vibration from passing trucks. I run my 6 volt ones from a 9v alkaline cell or from NiMH AA or C cells. Their only disadvantage is the size and weight, but if you are still hung up on that you just have not ridden enough at night.

After the barricade light I added smaller yellow blinkers. The best was something called the Far Out Flasher, sold by Schwinn stores in the 80's and by the late Ed Kearny (Bicycle Lighting Systems). The Belt Beacon was another, and I used those on my helmet, mounted with Velcro, juiced up by adding chrome tape to make a reflector behind the bulb. Yellow is still the best color for a flasher, since the population is aging, and red eyesight gets dim as eyes age.

I have tried turn signals, but never felt that they were really recognized by the motorist. The rack-mounted ones are too close together to give much of a directional indication. I tried one back in the 1980's that attached to my wrist and blinked only when the arm was raised, but you would need two of those, and again I had no way to know if the motorist behind me knew what the blinker represented or not, since they had probably never seen one before. That idea was revived in 2008 and updated with LED's by Safe Turn in Australia. They seem to have disappeared, but others have new ones out.

Beginning about 1990 I added the now-standard red LED blinkers, since they had taken over as the light signature of a bicycle and that increases the probability of being identified early as a bike. I had one on my helmet, mounted with hook-and-loop. Their only problem is that they are too small, and to a driver small means far away, so the car may not realize how close you are. There are some improved LED lights out now, that I first saw at the September, 1999, Interbike show, including a Vista that has "wings" with 15 LED's in the center and five in each adjustable wing. Vista also has a standard size tail light with multiple LED's that is very bright, but costs $60 and is designed to plug into their rechargeable system. At the same show I bought a very large LED flasher being test-marketed at a Chinese exporter's booth designed for use by cars as an emergency road flasher, and packaged as a "Highway Safety Light." It is 4" x 6", and has 18 extremely bright LED's in three rows. It's called the Fast Field Model HW-18, and it cost me $10, probably the dealer price. The light runs on 4 AA cells, with a claimed life of "at least 25 hours" which is about what I get from it. It looks like the biggest, brightest led flasher you have ever seen. But it had no bike mount, so I had to make one from aluminum bar stock. I have one now on all the bikes we ride at night. It is heavy for an led light, at 9 oz. with the batteries. It was hard to find at first, since they are imported in car parts channels, but our local Target had them for while, and now there are at several sources on the Web. Not all of them are equal, and some are disappointly dim. One decent one is probably the Real Light by Necessary Options. It even comes with brackets for mounting on a bicycle.

In December of 2001 I got an email from an importer who claims that his product is not only the bright version but has bike mounts. It is sold only through bike stores, so you have to go to your local LBS and hope they have them. I don't know how to tell you how to distinguish the high output ones from the low output ones, so you are on your own.

I have replaced the incandescent blinking Far Out Flasher on my helmet with an Innova 24/7 led blinker. This is an octagonal light about 2" by 3" (50mm by 75mm) that velcros on well. It runs on a CR123 lithium primary cell. It is not approved for lithium rechargeables, but could run on two NiMH 1/5 AA cells. The CR123's are expensive in stores but cheap on the Web, and one lasts me for many night rides. The light has a rectangular LED area with a rotating switch that selects different blink patterns and colors of LEDs. I use the one that flashes rapid red then white then yellow and looks vaguely like a police car flasher.

I got a sample at Interbike of a single yellow led that screws onto a shraeder valve and goes around. It uses hearing aid batteries. Another one introduced in 2002 has flashier led blinkers, but they are smaller. Either model adds to rotating weight right at the rim and uses an expensive battery. Saw another good idea at Interbike--a string of LED's that you weave around the spoke nipples. They are doubled up, with one facing each side, and about 8 inches apart on the rim. When the wheel turns fast enough (over 15 mph) it creates a ring of fire. It runs on two AA cells in a holder zip-tied to the spokes near the hub. I installed mine on my night bike and it looked great! They were available from Mr. Happy's Galactic Tracers under the trade name RimLites, but I don't see their Web site any more. I had problems with the battery contacts, and the instructions say don't use it in the rain (!) Mine self-destructed when I got a stick in the spokes, and I am not using them any more. Somebody was also exhibiting a "Whale Tail" led blinker for helmets. I tried a small high-output red led flasher on my helmet to replace my old yellow Belt Beacon. It is attached with hook-and-loop. At present I am using an Inova 24/7 light on my helmet. It has red and white leds that blink in a very bright emergency light pattern, and runs happily for months on one CR2 photo battery.

In 2004 I sent for a Californeon helmet light. It's a neon-like band about a quarter inch (7mm) wide that goes around the helmet and sticks on with a 3M adhesive. The battery pack takes a 9 volt battery and clips on your belt. Looked ok in the basement shop, but the circuit board burned out in less than 10 minutes of use, and before I had a chance to see what it would look like outdoors.

In general, I believe in redundancy, with at least two of everything just like a car. Redundant filaments in my car headlight let me use the high beam with a handlebar trigger flasher as a warning or passing through short tunnels, and also would provide an emergency option if the low beam ever dies. (Car lights have a very long filament life.) Redundant tail lights are essential, since nobody has ever produced a completely reliable light for a bicycle. I also like to "layer" my tail lights, with one at the level of the wheel axle, one under the saddle, and one on the helmet. The more I observe about urban light clutter the more I favor big, big lights and lights that have a signature. You will find this concept better developed on Ken Kifer's Web page discussion of the Flashing Neon Light Display, although I would not favor his use of a diesel generator to power the array.

In 2010 the battery powering my car light failed once again and I bought a new Magicshine system from Geoman Gear. It is LED powered and uses a Soul P7 SSC LED with four led's on one die. The heat sinking is adequate, and it lights up the road. Unfortunately, it lights up a lot of other territory as well, and can blind people coming the other way if not adjusted carefully. On trails I push it downward when people approach. I use two of them. The original batteries were recalled, and I have the new replacement. If this light had a shaped beam with a sharp cutoff above the pavement it would be ideal.

Those who ride off road at night have found helmet-mounted lights useful. If you use one, be sure to mount it with hook-and-loop or the kind of breakaway mount developed by Jet Lites. And please don't flash your light in my eyes on a dark trail.

There is now a category of lights called LED flares. They are designed for traffic situations. They should be durable. I have not seen them in use yet.

Some things can help in addition to the active lights that you should primarily rely on. For reflectors I use the hottest 3M product I can lay my hands on to add reflectivity to pedals, shoes, cranks (flashes as the cranks go around), panniers, clothing, helmet, anywhere else. 3M markets a "snake" in Europe that weaves around the spoke nipples, and under headlights looks like a ring of white, identifying the bike immediately. The 3M demo video is very impressive. I am trying a similar product now from a company called Techflex. Their product is called Reflex, and was originally developed for electricians to make electrical cables in big buildings easy to find and trace. They sell it for brake cables, but other than adding a point of light I don't think that helps identify a bicycle very well. As a round circle in your wheel, however, it can be much more effective. I am using one on the front wheel of my night bike, but my panniers obstruct it in the rear.

You can find 3M Scotchlite in many local stores, but for their hotter stuff, you have to go to the Web to places like Itendi-tape. Be prepared to spend more, but the results are pretty impressive. I use it on helmets and some other spots, even though it adds only points, not an identifying signature.

Unfortunately, all reflective products depend on being in the beam of a headlight to have any light to reflect, so for a lot of situations they are not much help. But I frequently find that flashing pedal reflectors are my first warning that a cyclist without a headlight is approaching on a dark trail.

Flags are great for daytime. I use two on my recumbent. One has a blinking white strobe light on the top of the shaft. The blink of a strobe disappears too fast for the eye to follow it well, but combined with the flag it's better, and it gives a 360 degree flash. I asked a more experienced recumbent rider if his flag slowed him down. He said he did not know, but maybe, and for sure he felt slower with the flag.