Fixed gas detectors and gas analysers are in comparison to portable gas detectors placed ad a fixed location where they monitor the amount of gas in a location or process 24 hours, 7 days a week. Because fixed gas detectors make use of a transmitter, the readings can be monitored from remote locations. This makes the process safer and more accessible for employees.
Fixed detectors are used to detect a irregular or hazardous presence of gas in a specific area, with the function, of warning its surrounding in the event of potential threats. Equipped with sensors or cells, fixed gas detectors can measure the concentration of one or more types of gas, depending on the type of gas detector. Toxic gases are monitored and measured in parts per million (ppm), while Oxygen is measured in a percentage volume. Combustible gases are commonly 0-100% of the lower explosive limit (LEL). When fixed gas detection is used, all detectors signal before reaching their set alarm value.
The most commonly used fixed gas detectors are:
Catalytic Bead: Combustible Gases
Electrochemical for Toxic Gas Detection (Ammonia, Hydrogen Sulfide, Sulfur Dioxide, Carbon Monoxide)
Electrochemical for Oxygen Detection
Metal Oxide Semiconductor (Solid State)
Non-dispersive Infrared (NDIR): Combustible Hydrocarbons
Unlike portable detectors, fixed gas detection secures an entire area 24 hours a day. The detector can be connected to a detection system, which displays the gas concentration in numerical value and then triggers the servo-controls in the event of an abnormal value.