Not Bump Testing is Crowcon’s second in the series of Deadly Sins of Gas Detection. A bump test is the only reliable way to test a unit for many different faults that might not cause the detector to alarm. There are many reasons not visibly evident to the user why a portable gas detector will not react to gas. When an instrument is turned on, you can see that the battery and display are working properly, but that’s about all.
Why bump test?
From day to day, a detector may develop a variety of faults including:
- Dirt or debris blocking sensors
- Physical trauma breaking alarm sounders or other electrical components
- Incorrect cleaning solutions inhibiting sensors
- Pellistor poisoning by e.g. hydrogen sulphide
- High temperatures drying out electrochemical sensors
So how can you be sure your detector is working? The answer is through frequent and regular bump testing!
A simple test that keeps you safe!
A basic bump test checks a detector is working by briefly exposing the unit to the target gas. If the detector does not respond as it should, there is a problem. It couldn’t be simpler. So, why do people still not bump test regularly? The list of reasons tends to look like this:
- It takes too long
- It’s too hard and takes training
- The gas costs money
- There’s no law saying we have to
So, why not?
A full bump test is a little more involved. Even so, the average time to bump test is 20-30 seconds – less time than it takes to put on the rest of your PPE! Usually little to no training is required and depending on the detector, there may be semi-automated or automated systems available to do the bump test for you. This makes it even simpler, so there is not much excuse for not bump testing.
When to bump test?
Frequency of testing depends on the manufacturer’s recommendation and how frequently you use the unit can also be relevant. Since November 2010, EN60079-29 part 1 has been harmonised under the ATEX directive 94/9/EC (2014/34/EU). Therefore to comply with the ATEX directive, portable apparatus sensing flammable gases should have a functional check with gas before each day of use.
However frequently you bump test, remember that this does not remove the need to have gas detectors inspected, calibrated and serviced periodically by a competent individual. Nor does calibration and servicing remove the need for bump testing.