Vaisala GMP252 Carbon Dioxide Probe
Starting at $662.00

Not in stock. Usually ships in 1-2 weeks [?]

Need Help? Call a Calibration Engineer 1-800-884-4967

We're open 8:00am to 5:00pm ET


  • 0 to 10,000 PPM CO2 measuring range
  • IP65 classified housing
  • Accuracy:
    • 0 to 3000 ppmCO2 ±40 PPM CO2
    • 3000 to 10,000 PPM CO2 ±2% of reading
  • Long-term stability with CARBOCAP technology
  • Full temperature and pressure compensations
  • -40 to 140°F (-40 60°C) operating temp
  • Sensor head heated to prevent condensation
  • Calibration certificate included

The Vaisala GMP252 Carbon Dioxide Probe is a new intelligent probe for measuring carbon dioxide. This robust, stand-alone measurement device is designed for use in agriculture, refrigeration, greenhouses and demanding HVAC applications. It is suitable for harsh and humid CO2 measurement environments where stable and accurate ppm-level CO2 measurements are needed. The GMP252 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 GMP252.

The GMP252 incorporates an internal temperature sensor for compensation of the CO2 measurement according to ambient temperature. The effects of pressure and background gas can also be compensated for. The measurement range is 0 to 10,000 PPM CO2 and the sensor can be used for measurements even up to 30,000 ppm CO2 with reduced accuracy. The operating temperature range of the probe is wide and the probe housing is classified as IP65. Condensation is prevented as the internal sensor head is heated. The GMP252 is resistant to dust and most chemicals, such as, H2O2 and alcohol-based cleaning agents.

The GMP252 is a compact probe that is easy and fast to install in a number of ways. It's easy to plug in and plug out. The surface of the probe is smooth, which makes it easy to clean. The probe provides several outputs for the CO2 measurement, analog current and voltage outputs as well as digital RS485 with Modbus protocol.

Vaisala Indigo 200 Series Transmitter
Plug-and-play connection for compatible CO2, vaporized hydrogen peroxide, humidity & temperature probes
Vaisala 242659 Connection Cable
M12/5 N female to USB cable used to connect Indigo probes to a PC for use with Insight software
In Stock
Vaisala DRW244221SP PTFE filter
25mm diameter, female thread, porous sintered PTFE filter provides extra protection for GMP252 CO2 probe
Vaisala Indigo Compatible Probe Cable
Shielded 5-socket M12 female connection to open wire
In Stock
Vaisala Indigo Compatible Right Angle Probe Cable
90° shielded 5-socket M12 female connection to open wire
Vaisala 243257SP Probe Mounting Clips
2 metal clips and screws for mounting GMP251 or GMP252 probes
Vaisala 243261SP Probe Mounting Flange
60mm diameter flange with o-rings, gasket, and 4 screws for mounting GMP251 and GMP252 probes through a wall or surface
Vaisala CBL210472 MI70 Connection Cable
M12/5 N female to M12/4 male connectors for hooking GMP251 and GMP251 CO2 probes to the MI70 handheld indicator
Vaisala CBL210493SP Flat Cable
M12 5-pin, 3.3ft (1m) flat extension cable for temporary connections to GMP251 and GMP252 CO2 probes through a tight space
Vaisala DRW244827SP Calibration Adapter
Allows feeding reference gas to the probe through the adapter’s gas port when calibrating, suitable for tubing with 4mm inner diameter
Vaisala ASM212017SP Spray Shield Adapter
IPX9 rating, protects the GMP251 / GMP252 carbon dioxide probe from pressure water jets
Vaisala DTR250 Radiation Shields
Recommended accessory for GMP251 and GMP252 probes when used for outdoor CO2 measurements

Application Notes

Here's how some of our customers used this product.

CO2 Leak Protection on the Production Floor

The Background: Our customer food production facility that uses carbon dioxide to flash cool products after cooking. They seek a reliable means of detecting CO2 leaks.

The Problem: Although CO2 is not a toxic gas, exposure to high concentrations can lead headaches, drowsiness and, eventually, death by suffocation. If lines that supply CO2 to the production floor develop leaks, the production floor must be evacuated.

The Solution: We recommended the Vaisala GMP252 Carbon Dioxide Probe with the splash shield accessory. The GMP252 provides an analog output which can run to a controller or alarm. With ranges up to 20,000ppm it will not be saturated in a high concentration event.

High CO2 Level Detection with Local Interface and Datalogging

The Background: Our customer is an engineering group which focuses on the food market. They are concerned with high CO2 levels in a refrigerated space and will need to monitor CO2 at both the operator level and remotely, including local alarms and remote notifications. To satisfy OSHA requirements, they will also need to capture historical data.

The Problem: Levels of CO2 in the refrigerated space can easily be more than 5000ppm, well above the capacity of most CO2 transmitters. Additionally, there are not a lot of good ways to view the historical data.

The Solution: We recommended the Vaisala GMP252 Carbon Dioxide Transmitter, with a measuring range up to 10,000ppm, paired with the Vaisala Indigo 201 as the local display which then outputs a 4-20mA signal to the HOBO RX3000 Remote Monitoring Station which can log and switch additional relays as needed. This set-up satisfies all the application requirements expressed by our customer.

Monitoring Grain Silo Health

The Background: Our customer is an agricultural company that maintains a number of silos used to store grains. They seek carbon dioxide sensors that can be used to help determine grain spoilage within the silos.

The Problem: Low-level grain spoilage caused by molds, mites, and insects can be detected in bins by measuring the CO2 concentration in the intergranular air. These organisms produce CO2 as they respire. Therefore, by measuring the CO2 level, their presence can be detected before serious grain damage occurs.

The Solution: We recommended the Vaisala GMP252 Carbon Dioxide Probe. Silos typically monitor temperature and exhaust fans are activated if temperatures inside the silos become too hot. GMP252 CO2 sensors can be easily installed in the exhaust stream where they can detect the low levels of CO2, usually between 0.08 and 0.1%, which would indicate low level spoilage.