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D12-IR Combustible or CO2 Gas Transmitter

The D12-IR gas transmitter is a versatile infrared system used primarily for the detection of combustible levels of methane or other hydrocarbons.


The D12-IR gas transmitter is a versatile infrared system used primarily for the detection of combustible levels of methane or other hydrocarbons. It may also be used for monitoring CO2 levels, either in ppm or percent levels.

D12Ex-IR transmitters provide analog signals for remote interface and optional relays for local alarming functions. Two digital communication options, Modbus™ and Hart™, are also available. Certified for use in explosion hazard areas, the unit provides rapid and reliable detection of
hazardous conditions so that protective measures can be activated.

The D12Ex-IR is also available with an infrared sensor designed for CO2 measurements in ambient air or in pumped gas samples. Two carbon dioxide sensors may be specified, one for low range use and another for higher levels of CO2. The low range sensor may be scaled from 0-1000 PPM minimum to 0-5% maximum, while the high range sensor covers ranges from 0-10% minimum to 0-50% maximum.


  • Backlit LCD Display
  • Internal Data Logger
  • Non-Intrusive operating functions such as calibration, alarm setup, alarm reset, data view, and setup
  • Options are all available using a magnetic tool
  • No need to open the enclosure when making adjustments
  • Password Protection
  • Modular Electronics
  • Explosion Proof Enclosure
  • Scalable 4-20 mA: The output range for a particular sensor is programmable within the range boundaries set in that sensor
  • Three Internal Alarm Relays
  • Analog Output Simulation
  • Relay Output Simulation
  • Serial Communication Interface


Sensor Type Single path non dispersive infrared
Sensor Separation Maximum 100′ cable from sensor to transmitter
Range Combustible: 0-50% LEL min, 0-100% max
Methane: 0-100%
High Hydrocarbons: 0-10% by vol min, 0-100% by vol max
Carbon Dioxide: 0-1,000 ppm, 0-50% max
Nitrous Oxide: 0-1,000nppm
Accuracy +/-2% of value, but limited by available calibration gas accuracy
Gases Available Combustible gas, carbon dioxide or volumetric methane. Combustible gas selectable for methane, propane or butane Consult factory for other gases and vapors.
Response Time T90 < 20 seconds
Electronic Repeatability ± 1%
Electronic Linearity ± 0.5%
Zero Drift Less than 1% of full scale per month, non cumulative
Span Drift Dependent on operating environment but generally less than 1% per month
Serial Interface Hart (1200 baud modem interface)
MODBUS (1200-9600 – RS232 or RS485 s/w selectable)
Optional Alarm Relays Three SPST, 5 A @ 230 VAC resistive
Relay Coil Programmable either normally energized or normally de energized
Analog Output Powered at 4-20mA, 600 ohms maximum at 24 VDC
Power 12-30 VDC, 350 mA maximum (3W average)
Temperature Limits -40 to 75°C
Controls 4 magnetic switches on front of transmitter
Enclosure Class 1 Div 1, Groups B, C & D, T6
Weight 7.2 pounds

Ordering Information

Many other combinations available, for pricing, please call AFC International at 1-800-952-3293, 219-987-6825 or fax 219-987-6826 or email

Catalog No.
D12 Gas Transmitter, Integral Sensor Holder, no relays
D12 Gas Transmitter, Integral Sensor Holder, with relays D12EX-IR-2-1
D12 Gas Transmitter, Remote Sensor Holder, no relays, 25′ cable D12EX-IR-3-1
D12 Gas Transmitter, Remote Sensor Holder, with relays, 25′ cable D12EX-IR-4-1

Ordering Information – Sensors

Catalog No.
Carbon Dioxide Sensor, 0-5%/50% by vol
Carbon Dioxide Sensors, 0-1%/5% by vol 00-1904
Combustible Gas Sensor, 0-50%/100% LEL 00-1905
High Hydrocarbon, 0-100% by vol 00-1906
Nitrous Oxide Sensor, 0-1,000 ppm/1% 00-1997


D12-IR gas transmitter literature

ATI is now a Badger Meter Brand

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