Regular bump tests increase day-to-day safety at work

Mobile gas detectors are used for continuous measurement. They are an essential companion for everyday use. Testing their function is therefore especially important.

We refer to daily bump testing but it should be noted, visual inspection and function testing should be performed prior to each use.  Furthermore, bump testing should be performed after exceptional situations (device was dropped) or when there is a risk that the device is damaged (sensor poisoning).

Why should you test?

Testing an instrument using a known gas concentration (also known as a function or bump test) is the only way to guarantee reliable and correct measurement of and warning against gas hazards.

This test is important to verify whether the gas to be measured can flow through the dust and water filter to the sensor, to check that the sensor is properly calibrated, and to test that alarms are working and are set correctly.

View common reasons for malfunctions



The importance of performing a daily bump test can not be stressed enough but carrying out prescribed calibrations is at least equally as important, even if calibrations occur less frequently.

Calibration should be performed regularly, because environmental factors or ageing can cause changes to sensor sensitivity. Recommendations for calibration intervals can be found in the technical documentation for the device in question, or in national regulations.

Simple, quick bump tests can uncover potential malfunctions and significantly increase the safety of your employees.

Quick and extended bump test

The following comparison shows the differences between the two test methods. An extended bump test offers a greater degree of safety.

Quick bump test

Extended bump test

  • Usually checks whether the first alarm threshold is exceeded.

  • There are variations where pre alarm A1 is not checked, but rather a defined or calculated threshold. However, the quick bump test only ever has one threshold that must be exceeded and no thresholds that must not be exceeded.

  • Depending on how it is performed, minimum times for exceeding the threshold and maximum times until the threshold is exceeded can be defined to increase safety.

  • No substitute gas can be used in this test type. The test is performed with a set test gas.
  • The extended bump test generally checks whether a concentration is reached, which must fall within a tolerance range according to the test gas concentration supplied. The test gas concentration must therefore be known to the device or transmitted by the test station.

  • Times can additionally be defined, e.g. a minimum or maximum time.
  • A substitute gas can be used. In this test type, the gas detector automatically switches to the test gas selected previously.



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This article was adapted from content provided by Dräger