GMM220 Series CO
2
Transmitter Modules
M010115EN-D
1
INTRODUCTION
Vaisala’s GMM220 transmitter modules are versatile instruments for measuring CO
2
in
industrial applications. The CARBOCAP
®
sensor is silicon based and its operation is
based on the NDIR Single-Beam Dual-Wavelength principle. The modules can be
configured for different CO
2
measurement ranges and analog output ranges.
Figure 1. Dimensions of the Probes and Component Board of the GMM220 Series
(in mm).
The GMM220 module consists of a component board, cable and a CO
2
probe. The shorter
probe model (GMP221) is for higher and the longer model (GMP222) for lower CO
2
concentrations. A waterproof connector connects the probe to the cable. The probe also
features a non-volatile memory for storing the calibration parameters. This enables true
interchangeability of the probes and forms a good basis for easy field calibration.
MOUNTING
For power supply and analog outputs, the board is available either with pinheaders on
bottom side or with screw terminals on top side; serial interface has always a pinheader.
Figure 2 Dimensions of the Component Board (in mm)
If the board has pinheaders, mount it by soldering or plugging it into host board's female
connectors.
GMP221
GMP222
100
35
80
145
D18.5
D18.5
GMP221
GMP222
78
48
