Does the gas detector need to be zeroed when it is turned on?
Regarding whether it is necessary to "zero-adjust" the portable gas detector every time it is turned on and used. This is actually a good question, so what is going on with this zeroing step? As a standard procedure, perform the four basic steps in clean air each time the instrument is turned on.
1. Confirm the battery level
2. Zero adjustment
3. Air test
4. Clear peaks
Whether zero adjustment is required or not, there are the following points to note:
1) The key to air zeroing is knowing that you are in clean air. You should not zero an instrument unless you know you are in a clean air environment. Zeroing an instrument in a polluted atmosphere can confuse readings and may even obscure readings of concentrations of potentially hazardous gases.
2) If zeroing is necessary, but the surrounding environment is near a fire or smoky place, and there is no clean air, you should use zero air (compressed air to remove impurities) to establish a standard for your detector. Zero air will not damage your detector or interfere with sensor functionality.
In an unclean air environment, if the instrument is turned on, the combustible gas and toxic gas sensor reads 000, and the oxygen sensor reads 20.9, so what is the purpose of zeroing the gas detector? Assuming your gas detector isn't deliberately masking negative readings, zeroing at this point is of no benefit. So, if you turn on your instrument and the readings are normal or within your acceptable range, there is no need to waste time going through the zeroing process. You won't be any better or safer for it.
But if you are going to zero, make sure you do so in a clean air environment.
