Intrinsically Safe Gas Detectors FGD3 Series

Flammable (Hydrocarbon) Gas Detector

(using infrared sensor technology)

Intrinsically Safe Flammable Gas Detector


  • Detects a wide range of Hydrocarbon Gases
  • Standard range, 0-100% LEL (Lower Explosive Limit) or 0-100% volume, pre-calibrated for Methane (CH4).
  • May be purchased pre-calibrated for an alternative target gas such as Ethane, Propane, Butane, Pentane etc
  • Plug-in, separately certified infrared Ex d sensor.
  • Suitable for use in Zones 1 and 2 hazardous areas.
  • Three wire connection.
  • 8 to 24 volt dc operation (also requires an additional supply of 5.8 to 7.5 volts dc to power the sensor).
  • Industry standard 4 to 20mA output.
  • Digital display
  • Single operator calibration.
  • Marine version available.
  • Optional weather guard available.

Note - Infrared Gas Sensors cannot be used for the detection of Hydrogen.


The FGD 3 Infrared Flammable (Hydrocarbon) Gas Detector incorporates the latest generation of compact sensors incorporating infrared technology for the accurate detection of Flammable gas concentrations over various ranges up to 100% volume. The detectors use the industry standard 4-20mA current loop to convey the gas levels detected to a control unit. This means that under zero gas conditions 4mA is drawn from the supply, and under full scale gas conditions 20mA is drawn from the supply. The current varies linearly for gas levels between zero and full scale. The detector heads use a three-wire connection. While the loop current supplies the power required by the detector head electronics within the detector head, a second supply must be provided to power the infrared sensor and its associated circuitry.

Marine Version

A marine version of the FGD3 is also available. This version is housed in a cast aluminium enclosure to provide higher RFI immunity where high power portable radios are used in the close confines of a vessel. The enclosure is plated and painted in order to withstand the harsh salt spray environment of the marine industry. The digital display is fitted with a sliding stainless steel front cover which remains over the display window when not being viewed thereby maintaining the RFI shielding properties of the enclosure during normal operation.

FGD3 Weatherguard

An optional weather guard is available for installations exposed to the atmosphere or contaminants and is also suitable for use in other areas where hosing down takes place. The weather guard reduces the possibility of water or other contaminants entering into the gas sensor thereby improving the overall reliability of the gas detector in harsh environments. The weather guard is attached with tamperproof screws to ensure that it is not inadvertently removed.

Collector Cone

A collector cone is available which can be fitted around the sensor inlet in order to concentrate any gas present around the sensor and hence improve the detection ability. Mounting brackets are also available.

Mounting Kits

A Swivel Mounting Bracket and Ceiling Mounting Kit is available for use with this range of gas detectors. In addition, a duct mounting kit is also available. Please contact Status Scientific Controls to discuss your particular application.

FGD3-IR Series Data Sheet

Hazardous Area Certification Data

Certificate Number - BAS 01ATEX2300
II 2 G Ex ia IIC T4 Gb (-20 deg. C <Ta< +60 deg. C)
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Download Chinese Certification

FGD3 Flammable Gase Detectors - Order Codes

Stock No. Description
SS413-100L FGD3 Flammable Gas Detector - (4-20mA Output) - Range 0-100% LEL (Lower Explosive Limit) CH4
SS413-100V FGD3 Flammable Gas Detector - (4-20mA Output) - Range 0-100% volume Methane (CH4)
SS413-M-100L FGD3 Flammable Gas Detector - Marine Version - (4-20mA Output) - Range 0-100% LEL (Lower Explosive Limit) CH4
SS413-M-100V FGD3 Flammable Gas Detector - Marine Version - (4-20mA Output) - Range 0-100% volume Methane (CH4)
SS475 FGD3 Series Protective Weather Guard
SS429 FGD3 Series Collector Cone
SS374 FGD3 Series Swivel Mounting Bracket
SS375 FGD3 Series Ceiling Mounting Bracket

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