As retailers of gas detectors and other such equipment we are often asked to explain the difference between calibrations and bump testing. OHSA or the Organization for Health and Safety Administration advocates that you do a full calibration before each and every use.

However, in practice, safety managers come up with their own intervals as convenient. If the gas detectors are used irregularly, for example once in a month – it invariably should be calibrated every time. This gives the user confidence that the unit is going to respond as it should, without any malfunctioning. On the other hand, if you use company your gas detector few times a week, then they make do with an occasional bump test, making the need to calibrate the equipment less often.

On the onset, we would like to stress the importance of having the initial settings and calibration of your gas detector done by the vendor or a technician. Having incorrect initial settings on a gas detector such as percentage can cause the meter to give false readings. Some gas meters can also be set up to use varied kinds of calibration gas or different concentrations, resulting in different readings.

Coming to the definition of a bump test; it is a brief exposure of the monitor to gas to confirm that the sensors are responding and the instrument alarms are functioning. The bump test is not entirely effective when it comes to checking the accuracy of an instrument.

A calibration check on the other hand is performed by exposing the gas monitor to a certified concentration of gas. This is done for a particular length of time, to help ensure that it provides accurate readings.

With the gas detectors available in the market today, if you have concerns about the accuracy of the readings, you should ideally calibrate it rather than just doing a calibration check. Calibration usually takes the same amount of time, effort and gas, but will ensure the accuracy of the instrument readings, once done.

As a safety manager, if you are doing a calibration check, and the readings do happen to fall outside of the specified accuracy, you will very well have to do the full calibration test. So, we advise you might as well do it initially and get accurate results the first time around.

Some of the gas detectors require the use of more calibration gas for “calibration” mode than that for bump testing. Be sure to budget this in for those gas meters used more regularly. Health and safety should be the prime concern of safety managers, whether opting for a bump test, calibration check or the full calibration. The most important being said here is that before you or your employees use a gas detector on a job where their lives may be in danger; ensure it is checked with gas in some manner or the other.