Pressure sensor GMP251

carbon dioxideCO2O2

Overview
The Vaisala CARBOCAP® Carbon Dioxide Probe GMP251 is an intelligent, stand-alone percentage-level CO₂ probe for demanding applications such as life science incubators, cold storage and fruit and vegetable transport where stable and accurate percentage-level CO₂ measurements are required. The GMP251 uses Vaisala’s 2nd-generation CARBOCAP® technology with a new infrared (IR) light source for extended lifetime and excellent stability. It includes integrated temperature measurement for compensation and a heated sensor head to prevent condensation. A calibration certificate is included.

Part of the Indigo product family
The GMP251 is part of the Indigo product family and can be connected to Indigo series transmitters to extend functionality (display, relays). It is compatible with Insight PC Software for data handling and the Indigo80 handheld indicator for spot-checking. The GMP251 replaces models GMM221 and GMT221.

Features

• Measurement range 0 … 20 %CO₂
• Intelligent, stand-alone probe with analog (voltage, current) and digital outputs
• Digital interface: RS-485 (Modbus and Vaisala Industrial Protocol)
• 2nd-generation CARBOCAP® sensing with IR light source for superior long-term stability
• Wide operating temperature range: -40 … +60 °C
• IP65 housing for demanding environments
• Full temperature and pressure compensation for CO₂ measurement
• Integrated temperature measurement for CO₂ compensation
• Compensation for background gases (including O₂) and humidity
• Heated sensor head to prevent condensation

Key benefits

• All‑in‑one probe for easy and fast installation; smooth surface for cleaning and resistance to dust and many cleaning agents (e.g., H2O2, alcohol‑based agents)
• Reliable, accurate percentage-level measurements with stability in varying conditions and extended sensor lifetime due to the IR light source

Product documentation (available)

• Datasheets
• User guides
• Order form
• Indigo Family brochure
• Industry brochures (examples: Food industry / Efficiency and Sustainability)

Technical specifications

• Measurement range: 0 … 20 %CO₂
• Operating temperature range: -40 … +60 °C
• Sensing technology: Vaisala CARBOCAP® 2nd generation (IR light source)
• Outputs: analog (V, mA) and digital (RS-485: Modbus & Vaisala Industrial Protocol)
• Integrated temperature measurement for compensation
• Full temperature and pressure compensation for CO₂
• Compensation for background gases (O₂) and humidity
• Heated sensor head to prevent condensation
• Housing rating: IP65
• Calibration certificate included