Vaisala GMD20 Bedienungsanleitung PDF herunterladen

transmitter GMD20 and GMD20D M210292en-A

INTRODUCTION

Vaisala’s GMD20 uses silicon based CARBOCAP



sensor technology providing

excellent stability and reliability. The GMD20 transmitters require almost no

maintenance: the recommended calibration interval is five years in HVAC and related

benign applications. Transmitters are available without a display (GMD20 version) and

with a display (GMD20D version).

MOUNTING

The GMD20 transmitters are truly duct mounted. The distance between the probe and the

duct wall is easily adjusted by using the mounting plate. The mounting plate is fastened

with four screws ST.4.2x16-C-Z/A4m DIN 7981. Note that four ∅3.2 holes on the duct

surface are needed, as well as one ∅22...25 mm hole in the middle (see figure below).

Insert the transmitter through the mounting plate and adjust the distance.

Figure 1 Dimensions of the GMD20 and the mounting plate (in mm)

ELECTRICAL CONNECTIONS

Open the transmitter cover and remove the display board if there is one installed. The

cable is inserted through a rubber plug included in the package. Pierce the rubber plug

with a screwdriver or a similar instrument in order to open the hole for the cable. Then

insert the plug in the appropriate hole in the transmitter cover. Strip a few millimetres of

the cable insulation and insert the cable carefully through the rubber plug so that you can

connect the wires to the terminal block on the righthand side of the component board.

min 80 max 140

Ø15

1 2 3 4

CO 1

Inhaltsverzeichnis

Seite 1 - CO

CO2 transmitter GMD20 and GMD20D M210292en-AINTRODUCTIONVaisala’s GMD20 uses silicon based CARBOCAP sensor technology p

Seite 2

The nominal 24 V supply must be connected between terminals + and -. The analogueoutput is available at remaining terminals. The common wire is connec

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POWER SUPPLY REQUIREMENTSThe GMD20 transmitter is designed to operate from a nominal 24 VAC/VDC supply. Thepower supply should maintain the voltage be

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TECHNICAL DATACarbon dioxideMeasuring range 0...2000 ppm CO2 (nominal); with recalibration 0...5000 ppm CO2,0...10 000 ppm CO2, 0...20 000 ppm CO2Accu