CO2, Temp & RH Transmitter (CO2T/RHT)

CO2, Temp & RH Transmitter (CO2T/RHT)

The Flamefast Carbon Dioxide, Temperature & Relative Humidity Transmitter offers an accurate and cost-effective solution for the HVAC market, with 0-10V outputs for CO2, Temp & RH levels.

Using the built in Volt Free Contact allows the unit to be easily interfaced with a variety of systems including Ventilation, Window Control, Gas Safety, or with the optional LCD the unit can simply be used as a traffic light indication to raise awareness of high CO2, Temp or RH levels.

The CO2T offers four user selectable programs to cover various applications. Custom software profiles can also be provided to adjust the alarm and traffic light set-points as well as the relay configuration. The relay and traffic light can be configured to activate based on any combination of CO2, Temp & RH (CO2 only as default).


View FileCO2, Temp & RH Transmitter (CO2T/RHT)

Key Features

  • 24VAC/DC Power Supply
  • Optional CO2 readout (Temp & RH on -H model only)
  • Optional CO2 traffic light indication (can be configured for Temp & RH)
  • Volt Free Contact output based on CO2 (can be configured for Temp & RH)
  • Typical 15 year life expectancy
  • Self calibrating CO2 Sensor
  • Mounts onto any standard Single Gang Junction Box or Conduit Box

Technical Specification

Power Supply 24V AC/DC ±10%
Power Consumption 40mA
CO2 Range (0 - 10V) 0 - 2000 / 5000ppm
CO2 Accuracy ±50ppm +3% @NTP
CO2 Display Resolution 1ppm
Temp Range (0-10V) 0 - 50°C
Temp Accuracy ±0.3°C @ 20 - 40°C
Temp Display Resolution 0.1°C
RH Range (0-10V) 0 - 100%
RH Accuracy +/-2% @ 20 - 80%
RH Display Resolution 0.1%
VFC Output Rating SPST - 100mA @ 24V Max
Operating Conditions Temp 0°C to 50°C
Humidity 0 to 95% (NC)
Sensing Method Solid State NDIR
Response Time (T90) 30 Seconds
Typical Sensor Life 15 Years
Sampling Method Diffusion
Warm-up Time 30 seconds
IP Rating IP40
Housing Material Flame Retardant ABS
Approval CE


Height 125 mm
Width 86 mm
Depth 36 mm

Installer Selectable Options

  • Traffic Light Enable/Disable (White Backlight)
  • Traffic Light changeover levels and Volt Free Contact activation
  • Display Options:
    • On standard Model - replace PPM reading with 'CO2'
    • On -H model - remove RH readout

The CO2T has four factory set user selectable programmes to control the Volt Free Contact and LCD Traffic Light behaviour.

These are as follows:

Program 1 2 3 4
Green - Yellow 1,000 1,000 1,500 1,500
Yellow - Red 1,500 1,500 2,800 2,800
Relay Position N/O N/O N/C N/C
Relay Set Point   1,000 1,500 2,800 4,500
CO2 Range 2,000 2,000 5,000 5,000

Custom programs available on request

Part Numbers & Options / Accessories

Part No Description
CO2T CO2 Transmitter
CO2T-H CO2, Temp & RH Monitor
CO2T-P3 CO2 Transmitter c/w 10K3 Thermistor
RHT Temp & RH Transmitter
-L Adds a Traffic Light LCD to any of the above

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