Gas Monitors In Depth

Now we are going to look into gas monitors in a bit more detail. First, as a reminder, there are many manufacturers of gas monitors, different shapes, sizes. Make sure that you get the right one for the job you require and that you get the proper training. Read through the manual. This particular one we're going to look at as an example is, we feel, a good one because it is going to do four tests. Now the four tests is it would check you for any flammable gases. It would check for methane, or check for hydrogen sulphide. It'll also check for oxygen levels. Simply turn it on by pressing the button in the middle. And it's gonna do a numbered test initially, what we call in fresh air. Now this one has gone straight off. It has failed its oxygen checks. Now I need to turn it off by pressing the button in and hold the button in. That just demonstrates how quickly they will go into alarm if there is a failure. So there's no way you could use this if it was not fit for use. At some point you'll then get to the part where it will do a calibration test. Again, if it is out of calibration, it'll go into alarm. By reading through the manual, you'll soon recognize that we have different alarms for different faults.

We also have to, in some occasions, do what's called a bump test where we have to buy a special cradle that it fits in and do some pre-checks before you even use the gas monitor. Let's move over to one that is calibrated. And it takes roughly about 30 seconds in order to do all its checks to ensure that it's safe to use. It's worth noting that there are a number of symbols that you need to be familiar with. One, in particular, is known as a peak reading. We could find ourselves in a situation, you've lowered your gas monitor in, but there might be very low levels of a particular gas. Not enough to trigger it, but as you take it back out again, we'll need to scroll through to ensure there's no peak reading, because if there is we need to make a note of it and make sure that everyone knows that there are some slight gases that we need to be aware of but they weren't at a sufficient level in order to trigger off the alarm. Now, most of these are already pre-set. You might go to an environment where there's a particular gas known that you want to monitor for. By speaking with the actual manufacturers, they are able to help you to have it recalibrated to whatever measurement you need or whatever gas you might need. Finally, then, I've received this one, it's done all of its checks, it is confirming that there's 20.8 for the oxygen levels, and the other three indicators are all in zero.

So we could take that this is now ready to go. It'll start to flash green lights, and occasionally the thing will vibrate. So they have all been enabled and I'm now in a position to go over to the actual testing of the confined space. Moving on to calibration. Every six months, you now have to send the units off to be calibrated. Pull that calibration to ensure that each of these sensors are doing the job correctly. If we have a sensor that fails, for example, the oxygen one, that needs to be replaced and then recalibrated. On many occasions, the cost of that does not compare to the actual cost of the unit. It can be cheaper just to buy a new unit again. The manufacturers don't put any specified time which the filters will last, but usually, you'd expect two, three, four years from them. But that is depending on how often you use them. And again, the sort of working environments you might be involved in when using these. While they are able to resist a certain amount of work and being banged, they're not waterproof. So we need to be very careful that we don't drop it in water as that will damage the filters, which again, there will be a quite a cost implication for that. Moving on to its ability to last. It's good to give you anywhere between eight and 12 hours on its battery life before it needed to be re-put into the cradle again.

That is quite good because the amount of these situations where you need to do continuous monitoring, rather than turning it on, monitor, and then doing it on an hourly basis, which in some work environments is classed as acceptable based upon the permit to work system. But check the job and make sure you know how often you need to monitor that particular environment. How many gas monitors do we need? Well, that would be dependent on the type of working environment you're in. If you're staying close to the point of entry, it may be acceptable to have one, that's been lowered down and it stays in that vicinity. If however, you're now going to be moving away from your point of entry, then it is suggested you have one per person. So they're all designed on the back to be clicked on into place, and they become now an individual gas monitor. But we would still recommend keeping one in situ to protect your means of access and egress. There is a time delay on the buttons. That is to make sure you don't accidentally turn it on or turn it off. Press and hold down, and then the off is shown.