Vaisala recommends using a heated version of WMT700 in environmental conditions where snow and ice buildup are possible. Heating keeps the transducer temperature above 0 °C (+32 °F) and adds heating power only when there is a risk of ice build-ups.
The following options are available:
- Heating for transducers only (for freezing conditions). Maximum heating power is limited to 40 W and the average heating power to 30 W.
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Heating for both transducers and array arms (for extreme conditions). Maximum heating power is limited to 200 W and the average heating power to 150 W.
This option requires the 480 W power supply option in the weather station.
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Heating for transducers, array arms, and body.
This option requires the 480 W power supply option in the weather station.
The maximum power control is achieved by automatically sequencing the transducer heaters depending on the heating voltage:
- At low heating voltages, all the transducers are heated simultaneously.
- At mid-range, 2 of the transducers are heated.
- At high-voltage end, a single transducer is heated at a time.
A pulse width modulation (PWM) scheme is used to control the average heating power.