How to Calibrate a Gas Detector?
Image Source: Pixabay

How to Calibrate a Gas Detector?

Multi-gas sensors and other monitoring devices are critical for reducing injury and disease in the workplace. A lot of dangerous ambient conditions cannot be identified by human senses alone, and equipment that can measure the air in a confined space can make a difference between death and life However, machinery alone cannot protect life unless employees are adequately qualified to use and calibrate it. Calibration of smoke detectors is yet another aspect of routine equipment tests and is an integral part of creating a secure workplace. 

How to Calibrate

Keeping the reference points of the instrument consistent is vital for the protection of staff. Calibration drift can occur over time due to chemical deterioration of detectors and natural drift in electrical parts. Multi-gas detectors are subjected to intense external factors that can affect their efficiencies, such as humidity, temperature, airborne particles and vapours, sensor poisons and blockers, and elevated levels of target gases. Throw in that they can be dropped on hard surfaces or in water or treated frequently enough for vibrations to impact electrical parts, and the devices will require calibration to continue working efficiently.

It’s better to consider the manufacturer’s instructions for your gas sensor when the time is right to configure it. How you calibrate your devices depends on the industry you do, how many devices you need, and how much they are used. Some companies are comfortable manually tweaking their detectors because they do not have thousands of them, and some companies use sensors on a seasonal basis and are fine with adjusting them every time the sensors are used.

There are 2 checks to be done to decide whether the monitors are operating properly, depending on the requirements: a bump test and complete calibration. Conduct all tests in a safe atmosphere with fresh air and a qualified and traceable gas calibration.

gas detector calibration
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Bump Testing

A bump test before using a gas detector is strongly recommended and easy to perform. Bump tests reveal the gas detector sensors to the target gas in order to verify if the alarm is activated before you take the sensor to the field. To have more precise results, the devices must be zeroed before you examine them.

Your device comes with a loop and a hose usually to be secured over the sensor plate; connect the other end of the hose to the calibration gas and regulator, switch on the device and let it start, and open the regulator to allow enough gas to cause the alarm to flow into the monitor. It should take about 10 seconds and not more than 20 seconds for the display to be alarmed.

Evaluating the reading on the display with the quantity of gas present is how you decide whether the monitor is correctly calibrated. If the result is within an appropriate tolerance range (the supplier of the detection equipment will have acceptable tolerance limits), the calibration shall be verified; if not, progress to full calibration.

Full Calibration

If the findings of the bump-test for gas detector calibration are not satisfactory, or the detector has been repaired or seriously damaged, the multi-gas detector must be fully calibrated. Complete calibration changes the reading of the gas meter so that it reacts to a known concentration of test gas. Some disposable devices come with instructions indicating that no calibration is necessary for the life of the system, but for safety sake, frequent bump testing is important to ensure that the device reacts. The sensors in disposable devices are the same as those used in limitless life monitors, are just as responsive and are subjected to the same conditions.

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