All of us are aware of portable gas monitors, those instruments with the built in sensors that give out an alarm in case they detect the presence of a gas (or fail to detect a sufficient level of a gas like Oxygen). We all know how to use them. We use portable LEL meters, before starting any welding or “hot work” in a hazardous area, we use portable Oxygen gas detectors before attempting to enter a confined space area for working and so on. But can we use these meters for other purposes? Sure, we can. If you notice if you carry a perfectly calibrated Oxygen monitor to a remote unpolluted area, what reading do you expect. 20.8 % Oxygen or even slightly better (I am not considering high mountainous regions that are low in Oxygen content). What reading do you get in your plant near all your reactors and distillation towers and tanks? Maybe 20.6 % or even lesser. What does that say about your workplace? Do a little “workplace monitoring” with these things, you’ll be surprised.
Now for some fun with the LEL meters. Take one of these to all the designated “hazardous” areas (all the Division 1, Zone 1, areas) and the designated “safe” areas and monitor the LEL levels. If your area classification is still current, you should not get any surprises. If not, well, you need to really rethink.
Caveat: A hazardous area (Even a Zone 0 or Zone 1) does not mean that you will have explosive gases and vapors all the time. Of course not! Otherwise your plant is really something that can get shut down by the authorities. But if you take these readings for a sufficient number of times, you can find out if for example the boundaries of your hazardous areas are OK or should they be extended? Are your safe areas immune to those vapors that may creep in when say some manholes on nearby reactors are opened? Are your double mechanical seals on your pumps really working properly? And so on. One round in your plant with these little meters will really give you a picture of how things really are…good, bad or ugly.