General Post Office differential line detector, made by the Automatic Telephone Manufacturing Co. Ltd, c. 1910. Model number: RH461. In wood case with glass fronted dial. Used to detect the presence of a current of electricity and to measure its strength.
Details
- Category:
- Telecommunications
- Object Number:
- Y1969.55.3
- Materials:
- wood (unidentified), brass (copper, zinc alloy), glass and metal (unknown)
- Measurements:
-
overall: 175 mm x 135 mm x 70 mm,
- type:
- galvanometer
- credit:
- Gift of NW Telecomms G.P.O.