Skip to content

Comet CO2 Concentration and Temperature transmitter with RS485 output, built-in sensors


Free Shipping US Wide, Over $199

Easy 30 Day Returns

Best Price Guarantee

Expert Customer Service

why you should buy from weather scientific

Comet CO2 concentration and temperature transmitter with RS485 output, built-in sensors

CO2 - carbon dioxide level and temperature sensor.

CO2 concentration and temperature transmitter with serial RS485 output is specially designed for use in exacting interiors in building energy management and HVAC systems. It designed for easy installation on ordinary KU68 wiring boxes for household switches and sockets.

Large dual line LCD is possible to switch off.

Computerized design ensures long term stability and fail indication. Transmitter is designed for use in non-aggressive environment.

Green LED shines - CO2 concentration 0 to 1000 ppm
Yellow LED shines - CO2 concentration 1001 to 1200 ppm
Red LED shines - CO2 concentration 1201 ppm and more



  • Temperature
  • CO2


  • Measuring range -10 to +50 °C
  • Accuracy ±0.5 °C
  • Resolution 0.1 °C


  • Measuring range 0 to 2000 ppm
  • Accuracy ±(50ppm +2% from reading) at 25°C and 1013hPa
  • Resolution 1 ppm


  • Operating temperature -10 to +50 °C
  • Channels internal temperature sensor a CO2
  • Counted values dew point, absolute humidity, specific humidity, mixing ratio, specific enthalpy
  • Output RS485
  • Available temperature units degrees Celsius, degrees Fahrenheit
  • Communication protocol ModBus RTU, ARION, Advantech ADAM
  • Power 9-30 Vdc
  • Protection class IP20
  • Dimensions 88 x 106 x 33 mm
  • Weight approx. 150 g
  • Warranty 3 years


* the features may vary depending on the device type

  • accurate measurement of Temperature, Relative humidity, Dew point, Atmospheric pressure, CO2, Two-state events
  • industrial or interior design with protection up to IP65
  • integrated sensors, external probe, duct mount design
  • relays output 250Vac / 8A or 50 V on selected models


TSensor (3-4-1-0)

Sensor Reader (2-0-6-0)

Conversions - application for recalculation of values


Terms and Conditions COMET System s.r.o.


Instruction Manual

Quick Start Manual

Declaration of Conformity

Description of communication protocols of Tx3xx and Tx4xx transmitters with RS232 and RS485 communication interface



CATALOG - Digital sensors and regulators with serial RS485/RS232 output

Shipping is fast and FREE across the USA for all orders $199 or more. For more details about shipping see the full shipping page here.

We offer 30 Day Easy Returns. If you decide you don't need a product we'll take it back so long as it is in original and re-saleable condition. See the full details here.

Found a better price online? We'll match it or beat it if we can. 

All you need to do is let us know via phone or email ( and we'll let you know what we can do.

You will need to provide evidence of the better price online and it must include any shipping or taxes charged by that site. i.e. It needs to be the total price.

This only applies to new products, it does not apply to used condition products.