Gas Detector Use & Awareness


Gas Detector Selection

Some 8 years ago now we were asked if we could come up with a gas detection course that would help reduce the cost of repairs and increase the understanding of how units work. Of course it is also covered under the PPE legislation that all users of PPE should be suitably trained in its use. So the gas detector awareness course was born, this has since then constantly evolved to cover all the latest units that are available out there. The idea was, and still is, to show exactly what gas detectors can do and how each make does that. We also ensure that we cover all of the things that can cost you dear, like how you store and care for them.

There are certain things that all makes suffer from and then there are particular units which are far better at doing certain things, whilst others are better for different tasks. For instance you may want to look for an exotic toxic gas. Something like chlorine or ammonia and many of the cells that detect for this have far shorter life span than the standard sewer gas sensors. So this will certainly limit the number of manufacturers you can choose from as many of them concentrate on the largest market only, which is detecting sewer gases. This is fine but may mean that you need to select more than one manufacturer to fulfill your needs. This can often lead to increased cost as your service agent must be trained by the manufacturer to service their units so you may need to send them to different places for servicing. It is also the only manufacturers or genuine agents that can buy authentic spares and would be included in any recall should it need to happen.

All of the gas detection units out there offer certain aspects that are really good. But if you don't understand how they work it is almost impossible to do a risk assessment that will select you the correct product. This may be that you operate a jetting company and require a gas detector to ensure safety to your workforce when cleansing tanks. For this you will need the correct IP (ingress protection) rating, otherwise you may well have selected the correct gases but the unit will quickly become written off due to water ingress. Or you may require to detect things like diesel, petrol or aviation fuel. Without the correct understanding of how flammable sensors work you may well select a unit that detects for flammable gases but does not see what you are specifically looking for. This may sound obvious but would you ask?

Then we have the manufacturers tricks, specifications that are placed into a tender to ensure that other makes cannot be priced. These can be easily sorted if you know what to look for, an IP rating that may sound too good to be true. Then next to it there is the famous asterix (*), look in the small print and it may say something like, achieved this level of protection with blank sensors fitted. Well in reality I suspect every other manufacturer be able to state this too. But this is all of course pointless unless you are trying to ensure that no one else can quote. Blank sensors do not detect anything!

The problem is there are a vast amount of things that will stop your gas detector performing correctly, from poisoning to not conducting regular fresh air zeros. If you have ever sent your gas detectors of for servicing and you are quoted to fit new sensors do you ever ask the question, "well when did it stop working?". Now it may be an oxygen cell that was replaced and that may well be completely correct because it has exhausted its life expectancy, but would you know if it should be done under warranty or if its chargeable. Now if its a flammable or toxic sensor that is all together more worrying. As the question you now need to ask is when did it stop sensing and where we still using it thinking it was protecting us? This is why all manufacturers state that you should perform a bump test / function test regularly. This ensures that your gas detector will detect the gases you are looking for. The Americans are way ahead of us on this as they state that a bump test / function test must be performed prior to use or it can not be used. This is because they know of the problems that not doing this can cause. Take it from me, the only person I will never hear tell me that their gas detector didn't work when they needed it is the person that was using it when it didn't go off. So understanding why and how your gas detector works the way it does is crucial to selection and ultimately your safety. Knowing that certain sensor types or accessories will reduce the battery run time of your unit again help with the correct selection.

It may be that you need to analyse what gases you have come into contact with as they may show that a particular event happens at specific times during the day. This may help in deducing what is actually causing the problem and lead to a far quicker repair of the system you are working on. So if the log intervals are for instance only able to be set at 1 minute intervals this may or may not give you the data you need. This may also need to be looked at as some manufacturers will charge for your data to be stored where as others you can just simply download to your own PC or Company server. The answer in all of these cases is the best system for you is the one that gives you exactly what you want. So understand what you really need and the environment it will be used in. If its not getting wet but you really need simple calibration with a fully audit traceable system then this may not be the same make of gas detector that you have seen some one else using. There is a reason there are so many gas detector manufacturers out there and that is because there are numerous different applications for them. Fixed systems, personal multi gas, personal single gas and analytical to name a few. You will find that they are all good if used in the environment that they are suited to and very expensive to maintain if it isn't.

Then we get on to a pet hate, the manufacturers that state this unit never needs to be calibrated! Well this may indeed be true, but they very rarely make it obvious that you must bump test / function test it regularly! It is of course in the instruction manual, but we all know how often these are read. So when you see that blister packed single cell or personal multi gas detector state "no need to calibrate" remember to read the small print because I guarantee it will say that you must bump / function test it regularly. New sensor technology is always happening which is why gas detectors are now the size of a pack of playing cards rather than the size of a house brick like they used to be. But there are still certain principles that remain true if they are electrolyte or pellistor cells. Photo ionization and infra red then add another string to the bow making even more things detectable but can also present further problems.

So do your risk assessment and come up with what you really need. Ensure that you fully understand how the gas detector you are looking at works and ask questions. You are responsible for the lives of yourself and your workforce. In truth your decision will never be questioned unless it all goes wrong. Could you really sleep if you suddenly found out that an accident was caused through a poor selection choice?

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