Vaisala GMP251 Datasheet

GMP251 Carbon Dioxide Probe

For %-level measurements

Features

• Measurement range 0 … 20 %CO2

• Intelligent, standalone probe with analog and digital outputs

• Compatible with Indigo transmitters and Insight PC software

• Wide operating temperature range (−40 … +60 °C)

• IP65-classified housing

• Integrated temperature measurement for CO2 compensation purposes

• Compensations also for pressure, oxygen, and humidity

• Sensor head heated to prevent condensation

Vaisala CARBOCAPâ Carbon Dioxide Probe GMP251 is a new intelligent probe for measuring carbon dioxide. This robust, standalone measurement device is designed for use in demanding applications, such as life science incubators, where stable, reliable, and accurate performance is required.

Benefits

•Superior long-term stability

•Reliable and accurate

•Calibration certificate included

GMP251 is based on Vaisala’s patented, latest-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 GMP251.

GMP251 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 ... 20 %CO2 and the sensor performance is optimized at 5 %CO2 measurement.

The operating temperature range of the probe is wide (−40 … +60 °C

(−40 ... +140 °F)), and the probe housing is classified as IP65. Condensation is prevented as the internal sensor head is heated. GMP251 is resistant to dust and most chemicals, such as H2O2 and alcohol-based cleaning agents.

Ease of use

GMP251 is a compact probe with easy and fast plug-in, plug-out installation. The surface of the probe is smooth, which makes it easy to clean. The probe provides several output options, including analog current and voltage outputs and digital RS-485 output with Modbusâ protocol.

GMP251 can be connected to Indigo series transmitters for an extended range of output and configuration options. See www.vaisala.com/indigo.

For easy-to-use access to field calibration, device analytics, and configuration functionality, the probe can be connected to Vaisala Insight PC software. See www.vaisala.com/insight.

Applications

GMP251 is ideal for life science incubators, cold storages, fruit and vegetable transportation, and for all demanding applications where stable and accurate %-level CO2 measurements are needed.

A flow-through adapter with gas ports is available as an accessory, enabling tubing for easy and flexible remote measurement with a separate pump. A multiplexer can also be added for sampling gas from several locations. 1)

1)Third-party pump and multiplexer not provided by Vaisala.

Technical data

Measurement performance

Measurement range	0 ... 20 %CO2
Accuracy 1)
At 5 %CO2	±0.1 %CO2
At 0 ... 8 %CO2	±0.2 %CO2
At 8 ... 20 %CO2	±0.4 %CO2
Calibration uncertainty
At 5 %CO2	±0.07 %CO2
At 20 %CO2	±0.27 %CO2
Long-term stability
At 0 ... 8 %CO2	±0.3 %CO2/year
At 8 ... 12 %CO2	±0.5 %CO2/year
at 12 ... 20 %CO2	±1.0 %CO2/year
Temperature dependence
With compensation at 5 %CO2,	< ±0.05 %CO2
0 ... +50 °C (+32 ... +122 °F)
With compensation,	±0.045 % of reading/°C
0 … 20 %CO2,−40 … +60 °C
(−40 ... +140 °F)
without temperature compensation at	-0.25 % of reading/°C
5 %CO2 (typical)
Pressure dependence
With compensation at 5 %CO2	±0.05 %CO2
700 ... 1100 hPa
With compensation, 0 … 20 %CO2	±0.015 % of reading/hPa
500 ... 1200 hPa
Without compensation (typical)	+0.15 % of reading/hPa
Humidity dependence
With compensation, 0 … 20 %CO2,	±0.7 % of reading (at +25 °C (+77 °F))
0 … 100 %RH
Without compensation (typical)	+0.05 % of reading / %RH
O2 dependence
With compensation, 0 … 20 %CO2,	±0.6 % of reading (at +25 °C (+77 °F))
0 ... 90 %O2
Without compensation (typical)	-0.08 % of reading / %O2
Start-up, warm-up, and response time
Start-up time at +25 °C (+77 °F)	< 10 s
Warm-up time for full spec.	< 4 min
Response time (T90):
With standard filter	< 1 min
Flow-through option with > 0.1 l/min	< 1 min
With spray shield	< 2 min

Flow rate dependence (for flow-through option)

Flow rate dependence:
< 1 l/min flow	No effect
1 … 10 l/min flow	< 0.6 % of reading/ l/min

1)At 25 °C (77 °F) and 1013 hPa (incl. repeatability and non-linearity).

Compliance

Compliance marks	CE, RCM, WEEE
EMC compatibility	IEC / EN / BS EN 61326 1, basic
	electromagnetic environment

Operating environment

Operating temperature of CO2 measurement

Storage temperature

Humidity

Condensation prevention

Chemical tolerance (temporary exposure during cleaning)

Pressure

−40 ... +60 °C (−40 ... +140 °F) 1)

−40 ... +70 °C (−40 ... +158 °F)

0 ... 100 %RH, non-condensing

Sensor head heating, when power on

•H2O2 (2000 ppm, noncondensing)

•Alcohol-based cleaning agents (for example ethanol and IPA)

•Acetone

•Acetic acid

Compensated	500 ... 1100 hPa
Operating	< 1.5 bar
Gas flow (for flow-through option)
Operating range	< 10 l/min
Recommended range	0.1 … 0.8 l/min

1)Occasional short-term exposure to up to +90 °C (+194 °F) allowed, provided that the probe is fully installed inside the measured condition and power is switched on. Accuracy specification not applicable if used in temperatures above +60 °C (+140 °F).

Mechanical specifications

Weight, probe	45 g (1.59 oz)
Materials
Probe housing	PBT polymer
Filter	PTFE membrane, PBT polymer grid
Connector	Nickel plated brass, M12 / 5-pin
IP rating, probe body	IP65
Connector	M12 5-pin male
Dimensions
Probe diameter	25 mm (0.98 in)
Probe length	96 mm (3.78 in)

96 mm, Ø 25 mm

Filter

M12 male connector

12 mm 75 mm 9 mm

GMP251 dimensions