How to Maintain the Sensitivity of Carbon Monoxide Gas Sensors in Daily Use
Carbon monoxide sensors are widely used in scenarios requiring CO gas detection, such as mines, automobiles, and households. They can continuously monitor the concentration of carbon monoxide gas in the environment 24 hours a day, transmit real-time data to the monitoring platform, enabling remote monitoring of concentration changes at any time and anywhere.
Carbon monoxide sensors, especially electrochemical-based CO sensor modules, can automatically adapt to environmental changes and calibrate the sensor's aging curve. They feature high sensitivity, excellent gas selectivity, and strong anti-interference capabilities, maintaining stable detection sensitivity throughout their service life.
Working Principle of Carbon Monoxide Sensors
When carbon monoxide gas diffuses through the air holes on the housing and across the gas-permeable membrane to the surface of the working electrode, it undergoes oxidation under the catalytic action of the working electrode. The H+ ions and electrons generated by the oxidation reaction on the working electrode are transferred through the electrolyte to the counter electrode (spaced at a certain distance from the working electrode), where they react with oxygen in water through a reduction reaction. Thus, a reversible oxidation-reduction reaction occurs inside the sensor, continuously taking place between the working electrode and the counter electrode, and generating a potential difference between the electrodes.
However, the reactions on both electrodes cause electrode polarization, making it difficult to maintain a constant inter-electrode potential and limiting the detectable range of carbon monoxide concentration. To maintain a constant inter-electrode potential, a reference electrode is added. In a three-electrode electrochemical gas sensor, the output reflects the potential change between the reference electrode and the working electrode. Since the reference electrode does not participate in oxidation or reduction reactions, it maintains a constant inter-electrode potential (i.e., constant potential), and the potential change is directly related to the change in carbon monoxide concentration.
When the gas sensor generates an output current, its magnitude is proportional to the gas concentration. By measuring the output current through an external circuit connected to the electrode leads, the concentration of carbon monoxide can be detected with a wide linear measurement range. Therefore, connecting a signal acquisition circuit and corresponding conversion/output circuits to the gas sensor enables the detection and monitoring of carbon monoxide gas.
As precision industrial electronic instruments, carbon monoxide sensors are susceptible to external environmental factors during use, which may lead to inaccurate detection data and shortened service life.
In daily use, proper maintenance of the detector is essential to maintain the sensor's detection sensitivity. The following aspects should be noted during maintenance:
Installation: When installing the carbon monoxide sensor, keep it away from dusty areas.
Dust Removal: A large amount of dust will accumulate on the sensor surface after long-term use, seriously affecting its detection sensitivity. Therefore, regular dust removal should be performed to keep the instrument clean.
Moisture Prevention: Humid environments also affect the sensor's sensitivity and may even cause detection failure. Therefore, regularly check for water droplets inside the instrument and perform drying treatment promptly.
Cleaning: When cleaning the carbon monoxide sensor, avoid using cleaning agents or solvents to wipe the instrument, as this may damage internal components and cause chemical reactions on the sensor material.
Inspection: Maintenance personnel should regularly check whether the carbon monoxide sensor is in normal working condition to prevent alarm failure.
