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).
Results of a 180-hour test on tungsten contacts, noting misfiring, metal transfer, and rust.
| Identifier | WestWitteringFiles\G\August1921\ Scan58 | |
| Date | 11th August 1920 | |
| -2- Contd. for 180 hours during which time misfiring and contact sparking became worse. During the run the make ratio of the contacts had altered from the standard .5 to .83. This was probably due to the transfer of metal which had taken place as in previous tests of tungsten points. There was no perceptible resistance either before or after the test. The points were also discoloured and generally affected in the same way as other tungsten points have been, except for some slight scratches due to the rubbing. The roller in contact with the blade in this test was rusted up although oiled at the start, and deposited a considerable pile of rust in the bottom of the condenser housing. RJA. R.R. 235A (100 T) (S.H. 159. 11-8-20) G.{Mr Griffiths - Chief Accountant / Mr Gnapp} 2800 | ||