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).
Test report comparing the insulation resistance in Megohms for Bakelite and Redmanol materials at various temperatures.
| Identifier | ExFiles\Box 61\1\ scan0082 | |
| Date | 8th December 1924 | |
| RR 238 (150 BKS.) (D3 431-8·12·24) MP 306975 ROLLS-ROYCE LTD. INSTRUCTIONS. (2) To________________ 19___ Order No. P.D.46. Customer's No.________________ together with the corresponding minimum values allowed by the production test. Ratio in Megohms. Material | 16°C | 20°C | 80°C | 100°C | 20°C ------------------------|--------|--------|--------|-------|------ Production Test figures.| ≮ 67 | ≮ 56 | ≮ 1.2 | — | ≮ 56 Redmanol | 266 | 118.7 | 12.3 | 7.3 | 241 Bakelite x.616.B. | 770 | 630 | 20.9 | 13.2 | 564 From these results it is seen that the Bakelite case passes our production test easily, and is actually better than the particular Redmanol case with which it was compared; although it may not be as good as other Redmanol cases. The Bakelite case, however, does not show that reduction in leakage with repeated heating, which is usual with Redmanol cases. This can be seen from the last observation, which was a check reading taken at 20°C after the case had been taken up to 100°C. In order to confirm this point the cases have been returned for baking, after Signed________________ * Cont'd This Sheet must be filed on completion of the work. | ||