Description
The SD-21 operates on the electrochemical oxidation principle. When $SO_2$ gas enters the sensor, it undergoes a chemical reaction at the sensing electrode, generating an electrical current directly proportional to the gas concentration. This signal is then processed by the transmitter to provide a real-time reading on the display or control system.
The sensor is built into a rugged, compact housing designed for long-term stability and a typical service life of 2 years under normal operating conditions.








