Chapter 7 ___________________________________________________________ Troubleshooting
VAISALA _______________________________________________________________________ 97
Visibility Value is Continuously Too
Good
This can be caused by several reasons. Most probably the light path from
the transmitter to the receiver is disturbed.
1. The lenses may be excessively contaminated. A warning has been
received.
- Clean the lenses (see section Cleaning Lenses and Hoods on
page 84).
2. One of the hoods has been filled with, for example, snow or
leaves,. A warning is generated.
- Clean the hoods (see section Cleaning Lenses and Hoods on
page 84).
3. There is condensation on the lens surfaces. This is a sign of heating
failure.
4. There is an electrical fault in the transmitter or receiver.
- Check the status information with the STA command (see
section STA on page 75).
- Go to section Message Exists but Visibility Value Does Not on
page 96.
5. Mechanical alignment of the sensor has changed and the receiver
beam and the transmitter beam have lost their overlap. This can be
caused by, for example, a colliding vehicle.
- Return the sensor to Vaisala Calibration and Repair to get a new
chassis.
Visibility Constantly Too Low
Usually there is something disturbing the sample volume.
1. Check the condition of the hoods. If the hoods are twisted, consult
Vaisala.
2. Try to find a better direction for the receiver/transmitter optics. See
section Selecting Location on page 31.
3. Electrical fault. See items in section Message Exists but Visibility
Value Does Not on page 96.
To Next Page
Loading...
