How Critical Is Your Air
Testing and calibrating your gas detectors before every use could mean the difference between life and death.
Many gas detection users only want to hear what they want to hear, but those serious about the health and safety of themselves and those they are responsible for wanting the facts.
The facts are that you don’t know that you air is safe by simply turning the gas detector on then going straight to work. The sensors must be tested. Is this news to anyone? No it’s not…or at least it shouldn’t be. All gas detection manufacturers clearly state, in their operational and maintenance manuals, that you must test the detector prior to each critical use.
How Critical is Your Air?
Some manufacturers state that the period between calibrations can be as long as six months (not U.S. manufacturers), in an effort to gain market share because they think it’s what we want to hear. Right.
How often do I have to calibrate?
Answer: When “field” or “bump” testing indicates the sensors do not reach a high percentage of the “bump” gas value on the can, assuming the gas is within manufacturers “good by” date.
How often must I “bump” test then?
Answer: Before each critical use! If you do not use the meter for at least four weeks you are best served by, at the very least, “bump” testing to verify that the sensor have not croaked, as oxygen sensors can do. You also need to make sure that some eager previous user, looking to see the combustible sensor respond, has not applied his disposable lighter to the LEL sensor and voila…the LEL is either dead from over-ranging or has been poisoned. Poisoned by butane gas? That’s correct. The LEL sensor is looking for Lower Explosive Levels which are approximately in the 0-5% range, not 100%, which is what comes out of that disposable lighter. So how critical is your air and more importantly, how can you verify the safety and accuracy of your air? It’s simple. Make sure you “bump” test before each use and calibrate regularly, which, by the way, will assist in keeping the sensors “healthy.” Some sensors have the tendency to “go to sleep.” Regular calibration schedules not only keep your sensors healthy and verified, but it’s the law. OSHA’s confined space rule 20CFR 1901.146 recommends you follow the manufacturer’s calibration and maintenance schedule, all of which recommend “field” or “bump” testing at regular intervals.
It’s a Simple Procedure
I know you’re thinking this expensive and time consuming. After all, you need a Ph.D. to do this stuff don’t you? On the contrary, with today’s technology, the advent of advanced gas detectors, and the low cost of standard calibration gases (approximately $250-$300 per year) you can have the user doing the “bump” testing on a regular basis and keeping a log of their testing. When the “bump” test indicates a response less than 90% of the target gas in the bottle, you simply proceed with calibration, using the same bottle.
All of this takes, with the newer technology available today, about 3-5 minutes. No kidding, it’s that easy and you have given the user a level of confidence which is not conveyed when you hand them a detector that already has a calibration sticker on it from a calibration they didn’t perform.
So, how critical is your air?
John V. Carvalho III is the president and CEO of Apollo Safety, Inc.