What are the common misunderstandings when using gas detectors?
Misconceptions in selection
Common organic volatile gases such as benzene, alcohols, lipids, amines, etc. are not suitable for detection using catalytic combustion principles. It is recommended to use PID photoionization principles for detection. Because catalytic combustion sensors are not suitable for measuring hydrocarbon gases such as benzene, toluene, xylene, and other volatile gases, especially hydrocarbon compounds with benzene ring structures. The carbon chain is relatively strong and difficult to break under catalytic combustion, which can lead to incomplete combustion. Unburned molecules will accumulate on the surface of catalytic beads, causing the occurrence of "carbon deposition" phenomenon and hindering the subsequent combustion of other molecules. When the carbon deposition reaches a certain level, the combustible gas will not be able to effectively contact the catalytic beads, resulting in insensitive or even unresponsive detection. This is determined by the properties of the sensor itself and belongs to a selection error in the early stage.
Misunderstandings in acceptance inspection
Many customers are accustomed to high concentration gas testing after receiving the instrument to ensure product quality, such as using a lighter to release gas to test a combustible gas detector. This approach is not rigorous and can easily cause damage to the instrument. Because the detection range of the combustible gas detector is 0-100% LEL, which is one lower explosive limit (taking methane as an example, 0-5% vol), while the lighter gas is high-purity butane, far exceeding the detection range of the combustible gas detector.
And when using lighter gas for testing, the sensor will be impacted by 2-3 times or even higher concentrations, which can cause early attenuation or deactivation of the chemical activity of the sensing element, resulting in a decrease in detection accuracy and sensitivity; Heavy damage will burn the platinum wire and render the sensor useless. It should be noted that sensor failure caused by high concentration gas impact is not covered by the manufacturer's warranty and requires replacement at their own expense.
Attention: Gas detectors should avoid testing with high concentration gases, and standard gases should be used to check their working conditions.
3. Misunderstandings in use
After selecting the instrument in the early stage, please do not change the usage environment without authorization during installation. For example, if a customer purchases a hydrogen sulfide gas detector and installs the sensor in the pipeline to measure the concentration of hydrogen sulfide online, the instrument value will not respond after one week. After testing, it was found that the sensor had failed, and it will fail again within two weeks after replacement. The gas detector is designed to measure the concentration of gases in the environment. Online measurement of hydrogen sulfide concentration in pipelines is a change in the usage environment. The sensor of the hydrogen sulfide gas detector is based on electrochemical principles, and the degree of electrolyte loss is positively correlated with the concentration of hydrogen sulfide in the environment. The more hydrogen sulfide content there is, the faster the electrolyte consumption and the shorter the lifespan.
