Vaisala WXT510 - Manual (Page 27)

Chapter 3 ______________________________________________________ Functional Description
VAISALA _______________________________________________________________________ 25
Three fixed temperature limits, namely +4 °C, 0 °C, and -4 °C (+39 °F,
+32 °F, +25 °F)control the heating power as follows:
Th > +4 °C: heating is off,
0 °C < Th < +4 °C: 50 % heating power,
-4 °C < Th < 0 °C: 100 % heating power,
Th < -4 °C: 50 % heating power.
When the heating function is disabled the heating is off in all conditions,
see
Supervisor Message on page 108 .