Gas sensor interference and gas detector shortcomings
It must be emphasized that so far there is no gas sensor with special effects on a certain gas, that is to say, any gas sensor is not special for the detection of specific gases. For example, a gas sensor marked to detect carbon monoxide, if detected in the environment In the presence of high concentrations of hydrogen gas, hydrogen gas may also react on the sensor to obtain a signal higher than the actual carbon monoxide concentration, which is called cross-interference of the sensor. The manufacturer's task is to minimize this cross-interference through various physical or chemical methods, such as through the use of filter membranes and different circuit parameters to minimize the reaction of non-analyte gases.
On the other hand, cross-interference will also provide some convenience for instrument manufacturing in some cases. For example, carbon monoxide detectors 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, this 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.
Due to technical limitations, gas sensors must be calibrated and calibrated continuously in order to obtain more accurate measurement results. The general technology requires a functional test (pump test) on the instrument before each use. If the measurement result of the instrument is within the error range of the instrument, the instrument can be used normally, and once the test result deviates from the normal error range Otherwise, the instrument must be recalibrated before it can be used.
