Vaisala WXT536, Руководство пользователя

Страница: 174 / 235

User’s Guide ______________________________________________________________________
172 _________________________________________________________________ M211840EN-C
The heating temperature should stay above 0 °C when the heating is on
(except in extremely cold conditions where the heating power is not
sufficient). The heating voltage Vh should correspond to the heating
voltage supplied. If there is a remarkable deviation, check the wiring.
Note that wire gauge should be large enough to avoid remarkable
voltage drop in the cable.
Operating Voltage Control
The supervisor message aSU shows you continuously monitored supply
voltage level (Vs). In case of deviations between the supplied voltage
and monitored voltage, check the wiring and the power supply. See
Supervisor Message on page 144 .
Missing Readings and Error
Indication
If the transmitter is not able to measure the wind, it indicates a missing
reading in the output. The most common reasons for measurement
problems are foreign objects, such as ice, birds, or other foreign objects,
on the line of measurement, or sound reflections from nearby objects,
such as wind tunnel walls.
NOTE
In case AC or full-wave rectified AC is used for the heating, the Vh
measurement behaves as follows:
While heating is off, Vh indicates the positive peak value (V
p
) of the
heating voltage waveform.
While heating is on, Vh indicates:
- 0.35 x V
p
in case of AC voltage
- 0.70 x V
p
in case of full-wave rectified AC voltage