Gas detectors require bump testing to check the gasses this is day to day practice this is normally done outside before a shift , I am only speaking on my experience with a Altair 4x if this had interchangeable batteries you would have to carry the bump test inside I guess to re bump test it so you no it’s working correctly again ?
Bumptesting should, in a work environment, be carried out in accordance with a Risk Assessment carried out for the environment that you are working in and also with reference to the manufacturer's instruction. I apply the same logic to recreational use.
As a "competent person" (there's a nasty little legal term) and as the "Appointed Person" (there's an even worse legal term, note the capitalisation ::)) and as it's my ass on the line if it all goes Pete Tong then I do it and record it every Monday morning and after any event which I think may have had an effect on the operation of the monitor e.g. submersion in water, caked in mud and washed off, a false alarm or any fault that I had cleared.
If I went down the same dry, clean shaft every day Monday to Friday for three weeks and the monitor didn't get wet/dusty/muddy etc then I would only bump test every Monday morning.
On the subject of batteries, applying the same "workplace" logic to a recreational setting, then if you have to stop to change the batteries there is something wrong with your modus operandi. Get yourself some better batteries, a better monitor or keep out. It's just one more thing that can go wrong. if you are genuinely actually in an environment where you genuinely actually need a gas monitor and not just wearing it to score cool points or to make your trip feel dangerous then stopping to change batteries is just plain ridiculous frankly. You simply are not properly equipped. :curse: