Aluminium, white - black lettering

The fluid-filled, closed measuring system consists of a WIKA SC15 temperature sensor, a measuring capillary and a bourdon tube. Heating the temperature sensor leads to a volume change in the closed system and thus a change in the pressure. This is transferred through a measuring capillary to the bourdon tube and, through the angular motion of the pointer shaft, to the dial on the display. When the switch point is passed, the switching disc (cam disc), fitted to the pointer shaft, triggers the microswitch.