Gas Detector response time
Response time represents the response speed of the gas sensor to the detected gas. In principle, the faster the response, the better, that is, as soon as the gas sensor is exposed to the measured gas or the gas concentration changes, the resistance of the device will immediately change to its determined resistance. But in reality it takes some time to reach a stable value. The response time tres is defined as the time required for the resistance to reach 90% of the stable resistance value at the concentration after the element is exposed to the gas to be measured. It is defined as the response time and is often expressed in tres.
Gas Detector recovery time
Different from the response time, the recovery time indicates the desorption speed of the gas sensor to the detected gas, also known as the desorption time. Likewise, I hope that this time will be as soon as possible. The recovery time trec is defined as the time required for the element to be separated from the detection gas until its resistance value returns to 10% of the resistance value in normal air. It is defined as the recovery time and expressed by trec.
Gas sensors and their classification
A sensor is a device or device that can be measured and converted into an available output signal according to a certain rule, usually consisting of a sensitive element and a conversion element. Among them, the sensitive element refers to the part of the sensor that can directly sense or respond to the measured; the conversion element refers to the part of the sensor that can convert the measured sensed or responded by the sensitive element into an electrical signal suitable for transmission or measurement.
Gas sensors mainly include semiconductor sensors (resistive and non-resistive), insulator sensors (contact combustion and capacitive), electrochemical (constant potential electrolysis, galvanic battery), as well as infrared absorption and quartz oscillation. , optical fiber type, heat conduction type, surface acoustic wave type, gas chromatography, etc.
zero drift
Zero point drift refers to the phenomenon that when the Gas Detector is used for a period of time or applied to a new environment, the indication value of the Gas Detector in clean air or an environment without this gas is greater than (positive drift) or less than zero (negative drift) .
