CO₂ Probe GMP251

The Vaisala CARBOCAP® Carbon Dioxide Probe GMP251 is an intelligent, stand-alone, %-level probe for measuring CO2 in life science incubators, cold storage facilities, fruit and vegetable transportation, and in all demanding applications where stable and accurate percentage-level CO2 measurements are needed. The operating temperature range is -40 … +60 °C and the measurement range is 0 … 20%CO2.

The GMP251 is based on Vaisala’s unique,second-generation CARBOCAP® technology that enables exceptional stability. A new type of infrared (IR) light source is used instead of the traditional incandescent light bulb, which extends the lifetime of the GMP251. It has full temperature and pressure compensations of CO2 measurement – integrated temperature measurement for compensation purposes. The sensor head is heated to prevent condensation. Digital output over RS-485: Modbus & Vaisala Industrial Protocol. A calibration certificate is always included with the product

The GMP251 probe is part of the Indigo product family and can also be connected to the Indigo500 and Indigo200 series transmitters to extend its features, for example, for a display or relays.

The GMP251 can also be used with with the free Insight PC Software.

For spot-checking, the ideal choice is the Handheld CO2 Meter GM70.

The GMP251 replaces the following discontinued products: GMM221 and GMT221. Please note that spare parts and accessories for the GMP221 probe are still available and can be purchased in the Vaisala online store.

For an introduction to the product, see the video below.

Measurement range 0 … 20 %CO₂
Intelligent, stand-alone probe with analog (V, mA) and digital (RS485) outputs
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
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Key Benefits

Easy to use and clean
The GMP251 is a all-in-one probe, which makes it easy and fast to install. The probe is resistant to dust and most chemicals, such as, H2O2 and alcohol-based cleaning agents. The probe's surface is smooth, which makes it easy to clean.
Reliable and accurate
With the wide operating temperature range, the GMP251 is suitable for a large number of applications. The probe provides accurate and stable measurements also in varying conditions.

Watch the video

Introduction to GMP251 and GMP252 probes

Product Resources

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Indigo500 series dual-probe support

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Benefits of Measuring CO2 Reliably in Cold Storage Applications

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Accurate CO2 Measurement in the Food and Beverage Industry

Accurate CO2 measurements in the food and beverage industry

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