Misuse of gas detectors

Update:30-08-2019
Summary:

  Objectively speaking, the reason why gas detecto […]

 

Objectively speaking, the reason why gas detectors cannot be used or damaged is that quality factors are only part of the choice of ordinary manufacturers, most of which are caused by improper selection and improper use. The following Dreier lists the gas detectors for you. Please pay attention to the common misunderstandings.

Acceptance error: Test case using high concentration gas: After installing the flammable gas detector on site, the customer uses a lighter to test whether the detector is working properly. After the ventilation test, the detector alarms but cannot be reset to zero. After normal use, after detecting the damage of the sensor, all return to the factory to pay for the replacement.

Analysis: Many customers prefer to use high concentrations of gas for testing during acceptance. This method is very inaccurate and can easily cause damage to the instrument. The detection range of the combustible gas detector is 0~100% LEL, the lower explosion limit is lower (methane is 0~5% vol), and the gas of the lighter is high-purity butane, which far exceeds the detection range. The range of combustible gas detectors.

When tested with a lighter gas, the sensor will be subjected to 2 to 3 or more shocks and the chemical activity of the sensing element will be attenuated or deactivated in advance, resulting in reduced detection accuracy and sensitivity. The platinum wire is blown and the sensor is scrapped. It should be noted that the manufacturer cannot guarantee sensor failure caused by high concentration gas shock and needs to be replaced at its own expense.

Analysis: Most flammable gas detectors on the market use the principle of catalytic combustion. The principle of catalytic combustion is to use the catalytic energy to produce low-temperature flameless combustion on the catalytic element, and the heat of combustion causes the temperature of the component to rise. The resistance of the component is detected by the Wheatstone bridge, and the change in the resistance value is detected to achieve the purpose of detecting the concentration of the combustible gas.