How much do you know about gas detector sensor cross-interference?
It must be emphasized that so far there are no gas sensors that are specific to a certain gas. That is to say, any gas sensor is not specific for the detection of specific gases. For example, a gas sensor marked to detect carbon monoxide will not detect the presence of carbon monoxide in the environment. If there is a high concentration of hydrogen, the hydrogen may react on the sensor and produce a signal that is higher than the actual carbon monoxide concentration. This is called sensor cross-interference. The manufacturer's task is to minimize this cross-interference through various physical or chemical methods, such as using filter membranes and different circuit parameters to minimize the reaction of non-measured gases.
On the other hand, cross-interference will also provide some convenience for instrument manufacturing in some cases. For example, a carbon monoxide detector can be used to detect hydrogen. Of course, the premise is that there is only hydrogen and no carbon monoxide in the environment. At the same time, the sensor needs to be calibrated with hydrogen. , our common carbon monoxide/hydrogen sulfide dual sensor is also manufactured by the manufacturer by taking advantage of the cross-interference characteristics of carbon monoxide and hydrogen sulfide sensors. It can detect carbon monoxide and hydrogen sulfide at the same time, achieving the purpose of detecting two gases at the same time with one sensor.
Due to technical limitations, gas sensors must be constantly calibrated to obtain more accurate measurement results. General technology requires that the instrument be functionally tested (pump test) before each use. If the measurement results of the instrument are within the error range of the instrument, the instrument can be used normally. Once the test results deviate from the normal error range, The instrument must be recalibrated before it can be used.
