ISC #5: How long should the sensor be replaced for your gas detector?

We are frequently asked by customers who use gas detectors how long it takes to change sensors in gas detection devices, which is really simple but not really clear.
Is there really no alternative recommendation or schedule for sensors in your gas detector? It can be explained as follows: Changing the sensor is not the same as changing the gearbox oil in your motorcycle, but it is very similar to pouring gasoline into the tank to drive. When the air sensors no longer have enough sensitivity to correct, it is simply like a car running out of gas, and simply, as long as the car has gasoline like your sensor has enough sensitivity, it is still usable.
Depending on the company, but Industrial scientific – USA has a calibration method that allows reading the remaining gasoline in the tank, which means that the remaining % of sensitivity of the sensor, it is called “Full span value” or “Span reserve value”. Span reserve value uses the sensitivity measurement of the sensor defined during calibration, it displays on the meter for each sensor at the end of the calibration process (which is great) , and will save this data inside the machine. A sensor with a Span reserve value that is less than or equivalent to 50% of the standard gas concentration, considered a broken sensor, should be replaced. The “running out of gas” lights will light up when the Span reserve value is up to 50~70% of the standard gas concentration, this is the time to consider whether to stop at the gas station to pump the tank full or go to the drain it and then drive the car.
So we conclude that:
As long as the sensor has enough sensitivity or a Span reserve value enough for the calibration to proceed successfully, the machine can still be used. It is not necessary to change the sensor until it can no longer be calibration.
Don’t forget to keep an eye on your gas watch so you can get home safely.