Several Non‑Negligible Characteristics of Gas Detectors
When using gas detectors to measure toxic gases, multiple gas‑detection technologies are available for selection. Meanwhile, no single technology can achieve fast, low‑cost and highly‑accurate measurement for specific toxic gases. Therefore, various factors need to be taken into account when choosing a proper toxic‑gas detection method.
① Colorimetric Tube Measurement Technology Besides toxic‑gas alarms, colorimetric tube technology remains a detection method for toxic and hazardous gases widely adopted in industry and environmental protection. Based on chemical color‑reaction principles, its greatest advantage is compensating for situations where no suitable sensor is available for instrumental measurement.
② Electrochemical Sensor The electrochemical sensor is a common and mature detection technology for toxic‑hazardous gas measurement in portable gas detectors. It features small size, low power consumption, good linearity and repeatability, as well as relatively long service life.
③ Semiconductor Sensor Semiconductor sensors consist of detecting elements made of metal‑oxide semiconductor materials. When interacting with gases, surface adsorption or chemical reactions occur, bringing about changes in conductivity, volt‑ampere characteristics or surface potential characterized by carrier movement. They can be used for measuring combustible gases at percentage‑level concentrations as well as toxic gases at ppm‑level concentrations.
④ Ionization Detector Ionization detectors available on the market mainly include the Photoionization Detector (PID) and Flame Ionization Detector (FID). They are widely used toxic‑gas detectors for gas‑chromatography equipment. When manufactured as standalone instruments, these two sensors become mainstream solutions for volatile organic compound (VOC) detection.
