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CO2 Monitor with LCD Display
Item No. vagmw21D

Allow up to eight weeks for delivery. The following meter is considered a "special order item."  

Delivery times are approximate and additional shipping charges may be applicable.  For quotes, please E-mail jsi@jsits.com, Call 82-31-479-4211/2


 Introducing the CARBOCAP

Vaisala's GMW21D wall mounted transmitter uses the new silicon based CARBOCAP sensor. The simple structure and reference measurement capabilities make this Single-Beam Dual-Wavelength NDIR sensor extremely stable and reliable.  The GMW21D transmitter is specially designed for Demand Controlled Ventilation (DCV) applications.  They are easy to install and requite almost no maintenance.

CARBOCAP Technology

The structure of the diffusion aspirated Single-Beam Dual-Walelength sensor is remarkably simple:  it consists of an infrared source, a sample cell, a tunable solid state interference filter and and IR detector.

CARBOCAP Technology

The tunable interference filter enables measurements at two wavelengths.   This means that the reference measurements can be made without the typical weaknesses of Dual-Beam sensors.

Superior Performance

The use of the new "carbocap" sensor and the  GMW21D monitor have several advantages:  high accuracy and excellent stability, negligible temperature dependence, ease of installation and reliable operation as well as a five year recommended calibration interval.  The measurement accuracy of the sensor is not affected by dust, water vapor or most chemicals.  Use of the  GMW21D transmitter results in considerable saving in installation, operation, maintenance and recalibration costs and ensures the best possible control of air quality.

Versatile Transmitters

The  GMW21D transmitter can be used independently or it can be incorporated into building energy management systems.

Technical Data

Measured Variables
Measurement range 0 ~ 2000 ppm (nominal; can be calibrated for other ranges: 0 ~ 5000 ppm,
0 ~ 10,000 ppm, 0 ~ 20,000 ppm)
Accuracy at 77 F (25C) against certified factory references. 

Including non-linearity and calibration uncertainty.

<30 ppm + 2% of reading

<1% FS

Temperature dependence of output (typical value) 0.05% FS/F (0.1% FS/C)
Long-term stability <5% FS/5 years
Response time (0 ~ 63% response) 1 minute
Output signal 0 ~ 10V
Accuracy @25C 0.9F (0.5C)
Measuring range 32 ~ 113F (0 ~ 45C)
Warm up time 30 minutes
Sensor Semiconductor IC
Output signals 0 ~ 20 mA or 4 ~ 20 mA and 0 ~ 10 V
Optional outputs relay, LonWorks interface RS 232 with serial COM adapter
Recommended external load:
Current output
Voltage output

max 500 Ohm
min. 1 kohm
Power supply (10 ~ 30 VDC) nominal 24 VDC/VAC
Power consumption <2.5 W
Warm-up time 1 minute, 15 minutes full specification
Operating temperature range +23 ~ 113F (-5 ~ +45C)
Operating humidity range 0 ~ 85% RH non-condensing
Weight 100 g (130g)

Made in Finland

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