Vaisala GMD110 Duct CO2 Transmitter


  • Designed for highly reliable CO2 measurement in air ducts
  • Vaisala CARBOCAPâ sensor
  • ± 40 ppm CO2 accuracy
  • Excellent long-term stability
  • Analog and Modbus RTU output option
  • IP65-rated housing
  • Traceable calibration (certificate included)

Dpstar is a leading supplier of environmental measurement sensors for temperature, relative humidity, pressure, dew point, CO2, and other environmental condition monitoring for industrial process application and research. Since the ’90s, we earned a reputation as a trusted partner to our clients through our commitment and dedication. We are an authorized distributor and supplier of measuring sensor solutions from renowned manufacturers in Vaisala. Vaisala is a global leader in environmental and industrial measurement. Building on 80 years of experience, Vaisala provides observations for a better world. Vaisala is a reliable partner for customers around the world, offering a comprehensive range of innovative observation and measurement products and services.

Vaisala GMD110 is a high-accuracy duct transmitter for measuring carbon dioxide in air‑handling systems and ventilation ducts. The transmitter is equipped with the renowned CARBOCAPâ sensor that has unique accuracy and measurement stability, which supports precise and reliable controls of HVAC systems even in demanding conditions and sites. The transmitter belongs to Vaisala HMDW110 Transmitter Series, which includes transmitters for duct mounting, IP65-rated wall transmitters, immersion temperature transmitters, and outdoor transmitters with integrated radiation shields.


  • Highly Accurate & Reliable. The duct-mounted transmitter Vaisala GMD110 is designed to measure carbon dioxide in demanding HVAC applications. With the outstanding accuracy of measurement, it is an ideal choice for demand-controlled ventilation systems even in challenging conditions. CO2 concentration is measured inside the duct without risks of leaks or wrong flow direction affecting the measurement. The temperature and flow dependencies of the sensor are negligible, and the measurement accuracy is not affected by dust, water vapor, or chemicals.
  • Stable Measurement. The high quality and excellent stability of the measurement enable precise and reliable controls of HVAC systems, even in demanding conditions or sites. The transmitter is equipped with the renowned CARBOCAPâ sensor that has unique capabilities in terms of precision and stability of the measurement. Its structure and reference measurement capabilities make this single-beam, dual-wavelength NDIR sensor extremely stable and reliable
  • Traceable Accuracy. All Vaisala GMD110 transmitters are individually adjusted and delivered with a traceable
    (ISO9001) calibration certificate. If required later on, the transmitter can also be field-calibrated using a Vaisala handheld meter or Vaisala Insight PC software.




Measurement performance
Measurement range 0 … 10 000 ppm CO2
Orderable with analog output scaled
to 0 … 2000 ppm, 0 … 5000 ppm, or
0 … 10 000 ppm
Accuracy 1)
0 … 3000 ppm CO2 ±40 ppm CO2
3000 … 10 000 ppm CO2 ±2 % of reading
Calibration uncertainty
at 2000 ppm CO2 ±31 ppm CO2
at 10 000 ppm CO2 ±105 ppm CO2
Long-term stability
0 … 3000 ppm CO2 ±60 ppm CO2/year
3000 … 6000 ppm CO2 ±150 ppm CO2/year
6000 … 10 000 ppm CO2 ±300 ppm CO2/year
Temperature dependence 0 … 10 000 ppm CO2
−10 … +50 °C ±0.05 % of reading/°C
−40 … +60 °C < ±0.1 % of reading/°C
Pressure dependence
Typical  +0.15 % of reading/hPa
Start-up, warm-up, and response time
Start-up time at +25 °C < 12 s
Warm-up time for full specification < 2 min
Response time (T90) < 1 min
1) At 25 °C and 1013 hPa (incl. repeatability and non-linearity)
Operating environment
Operating temperature −20 … +60 °C (−4 … +140 °F)
Storage temperature −40 … +60 °C (−40 … +140 °F)
Humidity 0 … 95 %RH, non-condensing
Condensation prevention Sensor head heating when power on
IP rating IP65
Mechanical specifications
Probe diameter 25 mm (0.98 in)
Probe length 126 mm (4.96 in)
Weight 215 g (0.47 lb)
Screw terminal wire size 0.5 … 2.5 mm2 (AWG 24 … 14)
Housing color White (RAL9003)
Mounting methods Screws or optional mounting flange
Probe PBT polymer
Probe filter PTFE
Housing PC + 10 %GF (UL-V0 approved)
Inputs and outputs
Output parameter Carbon dioxide (ppm)
Output modes 0/4 … 20 mA, scalable, max. load 500 Ω
0 … 5/10 V, scalable, min. load 10 kΩ
RS-485 with Modbus RTU
Power consumption 0.5 W typical, 1.1 W max.
Supply voltage
With current output 20 … 30 V DC
With voltage output or RS-485 12 … 30 V DC
Digital communication
Interface RS-485, non-isolated, no line termination
Default serial settings  19200 bps N 8 2
Protocol Modbus RTU
Modbus device address 240
Service port
Connector M8 4-pin male
Compatibility • Indigo80 handheld indicator 1)
• MI70 handheld indicator 2)
• Vaisala Insight PC software 3)
1) Requires M12-M8 cable 262195SP.
2) Requires connection cable 219980SP.
3) Requires USB adapter USB2 with M12-M8 cable 262195SP. Vaisala Insight software for Windows is
available at
EU directives and regulations EMC Directive (2014/30/EU)
RoHS Directive (2011/65/EU)
amended by 2015/863
EMC compatibility EN 61326‑1, basic electromagnetic environment
Compliance marks CE, RCM
Accessories and spare parts
Probe mounting flange 243261SP
Conduit fitting + O-ring (M16 × 1.5 / NPT1/2″) 210675SP
Conduit fitting + O-ring (M16 × 1.5 / PG9, RE-MS) 210674SP
USB adapter for Insight and M12 – M8 cable USB2 and 262195SP
Connection cable for GM70 (MI70) handheld meter 219980SP
Calibration adapter DRW244827SP
Porous sintered PTFE filter DRW244221SP