User's Guide _______________________________________________________________________ 
24  ___________________________________________________________________ M211659EN-C 
Selecting Location 
The conditions at the location should represent well the area of interest. 
Do not install the transmitter on the ceiling. Avoid placing the transmitter 
near heat and moisture sources, close to the discharge of the supply air 
ducts, and in direct sunlight. 
 
  1111-070 
Figure 9  Selecting Transmitter Location 
Use the mounting holes to attach the mounting base securely. Use at least 
two screws (not included, max screw diameter 4 mm). Remember to 
leave sufficient clearance below the transmitter to operate the slide. For 
mounting dimensions, see section Dimensions in mm on page 83. 
NOTE 
When bringing a cable through the wall, note that the hole may also 
supply air from outside the room into the transmitter. This may affect the 
measurement readings. For example, fresh concrete binds CO
2
 and may 
cause low readings, especially in new buildings. Seal the cable opening if 
necessary. 
 
NOTE 
Ambient pressure has a significant effect on CO
2
 measurement. If the 
elevation of the installation location is more than 100 m (328 ft) from 
sea level, make sure you are compensating for the effect of lower 
pressure. See Effect of Pressure on CO
2
 Measurement on page 65.