Vaisala PWD22 - Visibility Value Is Continuously too Good; Visibility Constantly too Low

Chapter 7 ___________________________________________________________ Troubleshooting
VAISALA _______________________________________________________________________ 95
CHAPTER 7
TROUBLESHOOTING
This chapter describes common problems, their probable causes and
remedies, and provides contact information for technical support.
Common Problems
CAUTION!
Servicing the equipment must be performed by qualified personnel.
Message Indicating Warning or Alarm
Open the command mode and check the status information with the STA
command (or poll Message 3 to get the same information).
- See section STA on page 75 for status message error and
warning descriptions.
- Check the monitoring values against the internal monitoring
limits. See Appendix A, Internal Monitoring, on page 105.
- If the Backscatter increased warning is active (see section STA
on page 75), clean the lenses and remove possible disturbances
from the optical path.
Message Missing
1. Does your terminal have the right settings?
- Change the baud rate, for example, to 9600 bps.
- Check that you have 7 data bits, even parity, 1 stop bits.
2. Give the OPEN command (see section OPEN on page 51).
3. Give other commands to see if PWD22/52 is already in the
command mode.
4. Go to the site.
- Take the maintenance PC (terminal), tools, and the calibrator set
with you.