Gas detectors are there to save your life, whether it is a fixed system or a portable detector, keeping them well maintained is an important part of ownership.
Our guest blogger this week, Julian, has put together simple steps to ensure your gas detector is up for the job as and when it’s required.
When cleaning any components of the gas detection equipment, do not use any solvent based or hydrocarbon (e.g. alcohol, benzene etc.) as these can contaminate the instrument sensors and cause spurious readings. Do not use hydrocarbon based lubricants (Silicones) at any time.
Regular servicing should be performed. Crowcon recommends a minimum of 6 monthly service intervals due to the sensor technologies used. This ensures accurate measurement of gas concentrations.
Ideally, the gas to be measured should be used to calibrate the gas detector. Calibration of fixed and portable gas detectors is normally done using a calibrated gas mixture from a cylinder, supplied by a gas company with a certificate of analysis. Normally recommended calibration gas should be half scale concentration, or as close as possible.
When it is not possible to obtain calibration mixtures containing the required gases, another gas mixture should be used which gives a similar detector response to the target gas(es). The detector output is corrected by use of a response, calibration or correction factor. Most detector manufacturers have tables that show the calibration gas mixture and correction factor for each target gas or vapour that the sensor will respond to. It must be noted that these tables are model-specific. Different types of sensor (for example infrared or catalytic) will have different correction factors.
Maintaining your gas detector also helps spread the cost of replacing parts such as sensors after they have expired, making sure your gas detector is fit for the job.
Gas detectors should be included in the plant maintenance schedule. The performance of most detectors deteriorates with time, the rate depending on the type of sensor and the operating conditions. For example a dusty, corrosive or damp environment can cause accelerated decline in response. These factors will affect the frequency of inspection, maintenance and calibration similarly, for portable gas detectors the user should consider the sensor type, operating conditions, required use and accuracy of the detector. Portable detectors should only be used if they are in good condition and are functioning correctly.
Training of employees is vital. The correct use of gas detection equipment is critical to health and safety of both staff and plant. Make sure everyone knows how and when to bump test their unit. Bump testing gas detectors, not only improves the response of the sensors it also makes your gas detector compliant for every-day use
Auxiliary equipment needs to be checked for dents, kinks, bends, blockages and holes in the sample probe, as these may affect the sample and give a false reading. A damaged battery or cracks in the casing could make the instrument unsafe or unreliable or both. Contamination, such as water or dust, could give false readings and may damage the instrument.
A damaged display would make the instrument difficult or impossible to read and a broken alarm may not register a hazardous situation. Any air inlet filters should be clean in order to allow an unrestricted air-flow into the instrument. It is also important to check the integrity of other parts such as the carrying case and shoulder strap, sounders and beacons.