Chapter 2 __________________________________________________________ Product Overview 
VAISALA _______________________________________________________________________ 31 
The parts of the support unit are shown in Figure 5 below. 
 
  0401-021 
Figure 5  Support Unit 
The following numbers refer to Figure 5 above. 
1 = Blower 
2 = Support arm 
3  =  Inner mast tube 
4  =  Weather protection hood 
5 = Mounting frame 
6  =  Outer mast tube 
 
The support unit is mounted to the outer mast tube of the LT31 mast 
construction. It consists of the mounting frame, weather protection hood, 
support arm, and blower. 
The only difference between the support unit of the LT31 transmitter unit 
and the LT31 receiver is that the support arm of the transmitter is 
equipped with a mounting flange for the PWD forward scatter sensor.