Phone: +1 (949) 583-1857||Fax: +1 (949) 340-6643

GIR900 Infrared Combustible Gas Detector

Product Literature

  • Combustible Gas Detector
  • Infrared Sensor
  • Built-in 0-20mA output transmitter
  • Explosion-proof
  • Aluminum or Stainless Steel housing

Keywords:  Combustible Gas Detector, Flammable Gas Detector, Hydrocarbon Gas Detector, Methane Detector, Butane Detector, Propane Detector, Infrared Gas Detector, Infrared Sensor

Features and Benefits

  • This economical, highly versatile, and reliable infrared combustible gas detector is designed to detect methane, propane, butane, ethane, pentane, and other combustible gases
  • Optical gas detector based on infrared operating principle
  • Measures concentration of gas 0 to 100% LEL
  • Immune to poisoning
  • Factory calibrated. No field calibration required
  • No moving parts, no maintenance
  • No Oxygen required to detect hydrocarbons
  • Reading immune to wind velocity
  • Suitable for on-shore or off-shore use
  • Designed to UL, CSA and CENELEC standards
  • 0-20 mA Analog output
  • Maintains calibration even after exposure to high gas concentrations
  • Continuous background of hydrocarbon gas does not shorten life
  • IP rating of up to IP66

Product Summary

GIR900 Infrared Combustible Gas Detector. Save money by installing this model in locations where the gas concentration display and relay contacts are not required. Uses the same IR sensor as our NOVA-Sensor for reliable and accurate measurements. A standard 4-20 milliamp circuit transmits the gas reading to other control equipment.  Designed to work with the NOVA-5000 control panel as well as be compatible with other control panels.  Available in standard, weatherproof, and dust-proof models up to IP66 rating.  Made in the U.S.A.


The GIR900 Infrared Gas Sensor is a completely self-contained device that measures the concentration of hydrocarbon gas accumulated in a protected area and transmits this information to a central point.

Operating Principle & Characteristics

Principle: The GIR900 Infrared Gas Sensor uses the proven non-dispersive infrared (NDIR) principle to detect and monitor the presence of gas. Using an infrared source lamp and an optical sensor with a narrow-band filter, an analysis of the optical absorption through the gas allows the concentration of the target gas to be determined. The strong fundamental absorption band centered at 3.32 micrometers is used for the detection of hydrocarbons. This allows short optical path lengths to be used while maintaining good resolution. A second infrared sensor operating at a wavelength not affected by the target gas is used to eliminate effects resulting from ambient and physical variations. These include temperature changes, source and filter degradation and particle scattering.

Characteristics: The GIR900 is designed to operate over the 0-100% LEL range and is particularly suitable for the reliable monitoring of general hydrocarbon levels in industrial safety applications. Each GIR900 includes a high-reliability microprocessor based transmitter/controller. The transmitter converts the output from the infrared sensor elements to a standard 0-20 mA signal which may be connected to a suitable NOVA-5000 Gas Detection Module, or to any other device with a standard 0-20 mA input. Output levels between 4 and 20 mA indicate the measured concentration of gas (0 to 100% LEL). An output of 2 mA indicates that the detector is in the calibration mode, while 0 mA indicates a malfunction or fault. Calibration of the transmitter output is initiated by activating the “calibrate” input on the transmitter. Calibration is completely automatic, requiring no hand adjustment of potentiometers. Calibration data is stored in the non-volatile RAM of the transmitter. The GIR900 is suitable for the most demanding applications. A large body mass insures excellent vibrational characteristics when used off-shore. Corrosion resistant materials permit use in harsh environments.

Architect's and Engineer's Specifications

Combustible gas sensing capability shall be provided by poison immune infrared gas detectors, contained in explosion-proof housings. The detector shall include control electronics which converts the measured gas concentration in percent LEL to the industry standard 0-20 mA signal. Calibration shall be completely automatic, with data stored in non-volatile RAM in the detector, and shall not require any operator adjustment. The detector shall be suitable for on-shore or offshore use, and the manufacturer’s data shall so state. Safety Systems Technology Model GIR900 Infrared Combustible Gas Sensor, or approved equivalent, shall be supplied.

Technical Specifications and Ordering Information

Technical Specifications

Power Input: 24 Volts DC nominal Will operate within specifications at any supply voltage between 16 and 32 VDC.
Range: 0-100% LEL Hydrocarbon
Warm-up Time: 6 minutes operational, 20 minutes to specification
Operating Temperature: -4oF to +122oF, -20oC to +50oC
Relative Humidity: 0 to 95% non-condensing
Ingress Protection: IP40, IP52 (with dust cover), IP66 (with spray shield)
Signal Output: 0.16 mA per % LEL
Resolution: 2% LEL
Repeatability: Zero: ±0.1% of full scale Signal: ±0.05% of full scale
Maintenance Interval: 6 months for verification of performance only
Analog Output: Standard 0-20 mA, self-powered source
Size: 2.2 inches (5.8 mm) diameter x 3.5 inches (88.9 mm) long Conduit connection is 3/4 inch NPT thread
Weight: 2 pounds (0.91 kg)
Approval Code: Class I Division 1 Groups A,B,C,D

Ordering Information

900-2-(Gas) Model GIR900 Infrared Combustible Gas Sensor with 0-20 mA output. Stainless Steel housing.

Optional Accessories

950-1 Junction Box with mounting ears and terminal block for sensor connections. Copper free Aluminum. Class I Groups C,D. Two ¾ inch NPT connections for conduit or cable glands.
851-1 Rain Shield to protect sensor from rain or snow
852-1 Dust Cover with 40 micron filter to protect sensor from airborne dust
854-1 Duct Mounting Assembly Kit for extracting a sample from an air duct
854-1-10 Water Spray Shield to protect sensor from hose sprays
858-1 Remote Calibration Adapter for applying test gas to sensor.