How do you know if the equipment is working correctly?
Portable gas monitors are vital early warning devices for maintaining the safety of personnel working in contaminated atmospheres.
There have been cases where a fault has prevented the atmosphere from interacting with the sensors, leading to the unit not detecting the change. In one case, a worker was overcome by lack of oxygen in an atmosphere heavily contaminated by nitrogen. Fortunately, there was a rescue plan in place and after being resuscitated. That worker lived to work another day.
Most manufacturers and relevant Australian Standards recommend regular calibration with certified test gases, in most cases, at set intervals, at least every six months.
Service may be required more often if the application is particularly aggressive or in the case of exposure to consistently high concentrations.
Manufacturers recommend re-calibration & service if a unit fails a bump/function test.
Other environmental factors including air pressure, temperature and humidity can also affect the accuracy of the unit. Completing a daily 'Fresh Air' or 'Zero Sensors' calibration 'tunes in' the sensors to todays conditions and is one part of the daily "before use" test requirement.