The galvanometer is a component on the panel of the latest version of the SDMT control unit. It provides the status of the DMT contact, just like the DMT buzzer. When the DMT contact is OFF, the galvanometer indicator is on the red side and the buzzer is OFF. When the contact is ON, the indicator is on the green side and the buzzer is ON.
 
Important Note: This galvanometer does not fit the panel of the traditional mechanical-only control unit. Please use the contact form below in case there is interest for the old version of this component.