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).
The comparative insulation tests of two different paraffin wax samples.
| Identifier | ExFiles\Box 164\5\ img150 | |
| Date | 26th August 1932 guessed | |
| COMPARATIVE TESTS OF SAMPLES OF PARAFFIN WAX. An insulation testing electrode having a diameter of 1.7 inches was placed in a metal container having a diameter of 4.25 inches this was then filled with Symonds wax and a leakage test carried out. At the atmospheric temperature (18°C) the resistance value was for all practical purposes infinity. This value remained constant, until the temperature was raised to 80°C when a leakage current of approximately 1 micro-ampere was observed on the galvanometer. This leakage was constant up to 120°C which was the maximum temperature reached. The melting point of this sample was found to be 60°C. Paraffin wax obtained from another source was next subjected to the same tests, the results were, there was no leakage at the ambient temperature (18°C), at 40°C the leakage was negligeable, at 80°C there was no leakage whatever. Above 80°C this wax was superior to Symonds wax, there being no leakage at all until 120°C was reached this being the highest temperature to which the wax was raised. The melting point was 75°C. From a point of view of leakage this wax is the better, but there is very little difference between either sample. | ||