From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Procedure for testing the insulation of a machine using a lamp and alternating voltage.
| Identifier | ExFiles\Box 51\1\ Scan184 | |
| Date | 19th July 1923 guessed | |
| -3- Contd. (9) The insulation of the machine should be tested while still hot by applying through a lamp an alternating voltage of 200 between the windings and the frame, when the lamp should show no sign of being lighted. ----------- XPC. | ||