General Monitors Model IR400 point IR combustible gas detector

The Model IR400 point IR combustible gas detector from General Monitors features a 3 s T90 response time to the presence of combustible hydrocarbon-based gases, which allows plant operators to respond quickly to gas leaks and avoid potential accidents. The fast response time is guaranteed even with a splash guard installed.

The IR detector monitors hydrocarbon-based gases including methane, propane, ethane, ethylene, butane, hexane, pentane and benzene. It features a self-diagnostic design to prevent false alarms and process shutdowns, and it monitors conditions such as supply voltage and optical path integrity. The device also features heated optics to eliminate condensation, and a dirty-optics indicator helps discriminate between true alarms and maintenance needs.

The device operates by measuring the absorption of infrared radiation passing through a volume of gas using a dual-beam, single-detector method. The IR detector measures the intensity of two specific wavelengths, one at an absorption wavelength and another outside of the absorption wavelength.  The gas concentration is determined by comparing these two intensities.

Using only 4.8 W of power, the device requires no routine calibration. It can be configured for analog output, Modbus and HART, providing a 2-wire RS485 addressable communication link that is used to monitor status and settings in order to simplify installation and maintenance. Its electronics are contained within a rugged, explosion-proof housing, and it has FM, CSA, ATEX, IECEx and BV approvals, the CE Marking, and is suitable for use in SIL 3 systems.