Vaisala DPT145 - Manual (Page 50)

User's Guide _______________________________________________________________________
50 ___________________________________________________________________ M211371EN-D
CHAPTER 7
TROUBLESHOOTING
This chapter describes common problems, their probable causes and
remedies, and provides contact information for technical support.
Solving Typical Problems
Some problems can be solved by simply resetting the transmitter. You
can reset the transmitter by disconnecting the power or issuing the
RESET command using the service port.
If resetting does not help, and if the problem is related to transmitter
software or settings, you can restore the factory configuration of the
transmitter by issuing the FRESTORE command. If you are unable to
solve your problem with the transmitter, contact Vaisala technical
support. See section Technical Support on page 52.
Table 10 Troubleshooting Table
Problem Possible Causes and Solutions
Dewpoint reading is not stable
after installation: reading
indicates slow drying.
This is normal behavior after installation. See
section Stabilization of Dewpoint Reading
After Installation on page 29.
Pressure reading is not stable:
reading indicates falling
pressure. Dewpoint
temperature may be rising.
Leak in the measurement environment.
Locate and repair the leak.
Transmitter outputs stars "****"
instead of measurement data
Possible causes: damaged sensor, incorrect
supply voltage, and unsuitable measurement
environment.
Power cycle or reset the transmitter, and see
if the problem continues. Check the active
errors using the ERRS command. Check the
power supply.
Unable to access transmitter on
the RS-485 line.
Possible causes: Incorrect wiring, unknown
serial settings, transmitter in POLL mode
with unknown address.
Check wiring. Try connecting as instructed in
section Unknown Serial Settings on page 52.
Issue the ?? command to make the
transmitter respond in POLL mode.