Do I need to set the gas detector to zero each time I turn the gas detector on?
As standard procedure, we train instrument users to perform four basic steps in clean air every time they turn on their instrument:
1. Confirm battery power
2. Zero adjustment
3. Ventilation test
4. Clear peaks
Whether zero adjustment is needed or not, there are a few points to note:
1) The key to air zeroing is to know that you are in clean air. You should not zero the instrument unless you know you are in a clean air environment. Zeroing an instrument in a contaminated atmosphere can cause confusing readings or even mask readings of potentially hazardous gas concentrations.
2) If you are zeroing, but the surrounding environment is near a fire or a smoky place with no clean air, you should use zero air (compressed air with impurities removed) to establish a standard for your detector. Zero air will not damage your detector or interfere with sensor function.
In an unclean air environment, if the instrument is turned on, the combustible gas and other gas sensors read 000, and the oxygen sensor reads 20.9, then what is the purpose of zeroing the gas detector? Assuming your gas detector doesn't intentionally mask negative readings (Insco's instruments don't do this), zeroing is not a good idea at this point. So, if you turn on your instrument and the readings are normal or within an acceptable range for you, don't waste time completing the zeroing process.
