heating resistor

The mechanical structure is actually driven by the heating resistor at its resonance.

Electrical resistors (including rheostats and potentiometers), other than heating resistors.

Heating resistors and temperature sensors are located around the circular perifery of the etalon retainer.

Problems with dew and frost (which particularly affect the CG 2 measurements) can be avoided by powering the heating resistors inside the CG 2 (12 or 24 VDC).