A7. Hydrogen sensors maintenance and calibration

The performance of most sensors/detectors deteriorates with time, the rate depending on the type of sensor/detector and the operating conditions (e.g. dusty, corrosive or damp environment). Functioning must be checked with the frequency recommended by the manufacturer.  Checking should include:

• appropriate cleaning, especially the head of the detector, to allow gas to reach the sensitive element;
• regular inspections for possible malfunctions, visible damage or other deterioration;
• that a zero reading is obtained in a clean atmosphere;
• that a correct response is obtained for exposure to a known concentration;
• that, if data logging is required, the logging period is appropriate for all data points over the required measurement time and can be stored in memory;
• the battery level, for portable instruments.

The best means to determine maintenance intervals for a sensor/detector is based on experience learned from use. For new installations it may be wise to carry out maintenance frequently at first (perhaps weekly), increasing the time intervals (to, perhaps, monthly) as confidence grows on the basis of the maintenance records with experience in the installation. Information on maintenance protocol should be found in the user manual supplied by the manufacturer.

It is recognised that this level of maintenance may not be practicable for domestic applications.