Instruction Manual

TECHNICAL DATA
Carbon dioxide
Measuring range 0...2000 ppm CO
2
(nominal); with recalibration 0...5000 ppm CO
2
,
0...10 000 ppm CO
2
, 0...20 000 ppm CO
2
Accuracy at 20°C against
certified factory references <±[30 ppm + 2.0 % of the reading]
(including repeatability and calibration uncertainty)
Non-linearity <±1.0 %FS
Temperature dependence
of output (typical) < 0.15 %FS / °C (reference 25°C)
Long-term stability <± 5 %FS / 5 years
Response time (0…63%) 1 minute
Operating conditions
Operating temperature -5...+45 °C
Storage temperature -20...+70 °C
Humidity range short term 0...85 %RH (non-condensing)
Air flow range 0...10 m/s
General
Analogue outputs 0...20 mA or 4...20 mA and 0...10 V
Resolution of analog outputs 0.5 % FS
Recommended external load:
current output max. 500 Ω
voltage output min. 1kΩ
Relay contact ratings max. 50 V 0.5 A
Power supply nominal 24 VDC/VAC (18...30 VDC)
Power consumption < 2.5 W average
Warm-up time < 15 minutes
Mechanics
Housing material ABS plastic
Housing classification IP65
(electronics housing)
Weight:
GMD20 140 g
GMD20D 170 g
ACCESSORIES
Order code Description
GMR20 Relay output option (not for the GMD20D)
GML20
LonWorks

interface option (not for the GMD20D )
GM35001 Calibration pipe
19222GM Calibration software kit (incl. disk and serial COM adapter)
GUARANTEE
Vaisala issues a guarantee for the material and workmanship of this product under
normal operating conditions for one (1) year from the date of delivery. Exceptional
operating conditions, damage due to careless handling and misapplication will void
the guarantee.
CO
2
transmitter GMD20 and GMD20D M210292en-A
4
*
M
210292
EN
*