Instructions for use of electrochemical gas sensors

　　一, The working principle

　　The sensor is composed of three electrodes, working electrode, opposite electrode and auxiliary electrode. The reference electrode is connected to the working electrode at a stable point, and the potential and potential change of the working electrode can be measured more accurately.

　　二, Use

　　Generally, electrochemical sensors are mainly used for single measurement, which means to measure the gas concentration of a single target gas in a single environment (that is, only one gas exists in a certain environment).

　　三, Calibration

　　Single measurement Calibration method When the sensor is used for a single measurement, the standard gas concentration of the measured gas is used for calibration.

　　四,Precautions when detecting different gases

　　The impact of high concentration measured gas has negative output. When the high concentration of the measured gas or the incoming measured gas directly faces the air inlet with pressure, there will be a large amount of measured gas entering the sensor, and the working electrode cannot react all of it in a short time, or due to pressure, the measured gas will enter the reference electrode, resulting in a positive signal to a negative signal at this time. If the concentration above the continuous load is exceeded and the continuous ventilation is prolonged, a recovery time of at least 10 hours is required before the secondary normal measurement can be carried out.

　　五,Standard gas test or calibration requires a flow rate of 300ml/min and a longer continuous ventilation of 3 minutes. When calibrating, avoid the gas with flow directly facing the air intake. Please adopt the side intake mode at a 90 degree Angle with the air intake, so that the sensor is in the state of diffusion measurement, to avoid the direct impact of the flow.