CO₂ Probe GMP252
for ppm-level measurements in agriculture, refrigeration, demanding HVAC, and for plant growth manufacturers
The Vaisala CARBOCAP® Carbon Dioxide Probe GMP252 is an intelligent, stand-alone, ppm-level probe. It's intended for measuring CO2 in agriculture, refrigeration, greenhouses, demanding HVAC applications, and for plant growth chamber manufacturers. It is suitable for harsh and humid CO2 measurement environments where stable and accurate ppm-level CO2 measurements are needed. The operating temperature range is -40 … +60 °C and the measurement range is 0 … 10 000 ppm CO2, and even up to 30 000 ppm CO2 with a slightly reduced accuracy.
The GMP252 can also be placed inside the Vaisala Radiation Shield DTR250 for measuring dynamically outdoor CO2 levels.


Part of the Indigo product family
The GMP252 probe is part of the Indigo product family and can also be connected to the Indigo500, Indigo300, and Indigo200 series transmitters to extend its features, for example, for a display or relays. The GMP252 can also be used with with the free Insight PC Software.
For spot-checking, the ideal choice is the Indigo80 Handheld indicator.
The GMP252 replaces the following discontinued products: GMM222 and GMT222. Spare parts and accessories for the GMP222 probe are still available and can be purchased in the Vaisala online store.
Features
- Measurement range 0 … 10 000 ppm CO2
- Can be used for measurements even up to 30 000 ppm CO₂ with reduced accuracy
- Intelligent, stand-alone probe with analog (V, mA) and digital outputs (RS485 with Vaisala protocol or Modbus)
- Superior long-term stability with the 2nd-gen proprietary CARBOCAP® technology
- Wide operating temperature range -40 … +60 °C
- IP65 classified housing
- Full temperature and pressure compensations
- Integrated temperature measurement for CO₂ compensation purposes
- Compensations for background gases: O₂, and humidity
- Sensor head heated to prevent condensation
Key benefits
Easy to use and clean
Reliable and accurate
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Product Resources
Application note

Optimized CO2 concentrations in greenhouses translate into higher productivity and higher quality
Learn moreCustomer case
