Chapter 6 ______________________________________________________________ Maintenance
VAISALA ______________________________________________________________________ 199
WARNING
Touching an operational blower fan can cause injury. Keep your fingers
and tools away from the air inlet. Power down the whole LT31, or switch
off the blowers in the service menu (see section Checking Operation
below) before replacing the particle filters and keep the menu open
during the operation. After replacement, switch on the blowers again.
Checking Operation
To check the operation, do the following:
1. Access
the
Main
menu of the LT31 user interface.
2. Press
H
on the keyboard to access the
Service
page.
3. Then
press
A (BLOW)
to easily switch on and off the blowers of
the receiver and transmitter.
Now a significant blower air stream must be noticeable in front of the
window panes of the measurement units of the LT31 transmitter and
receiver. During operation, the blowers must not generate any abnormal
noise. If abnormal noise is generated, the blowers need to be replaced.
See section Replacing Blower Unit LTB111 on page 220.
Replacing Particle Filter
To replace the particle filters which are mounted directly in front of the
air stream inlet of the blower system, the measurement head covers have
to be removed first.
1.
Loosen the three lock screws at each side of the measurement head
cover and carefully remove the cover from the measurement head.
See Figure 95 on page 140.
2.
Loosen the securing screw to access the particle filter. Tilt the
mounting frame for the particle filter slightly away from the
blower. Particle filter holder is shown in Figure 114 on page 200.