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 conditions of test and values for Power Factor and Volume Resistivity.
| Identifier | ExFiles\Box 164\5\ img237 | |
| Date | 26th February 1935 | |
| (2) POWER FACTOR. Conditions of Test. Measurement to be made on same specimen as for permittivity. Measurement at 50 cycles/second under a voltage gradient of not more than 50 volts/mm. Value At 25°C less than .0004 " 70°C " " .020 (3) VOLUME RESISTIVITY. Conditions of Test. Specimen to be cast, allowed to stand at room temperature for 22 hours, and conditioned @ 25°C. for 2 hours. Measurement to be made under a voltage gradient of 100 volts/mm. after 10 minutes electrification. Value Above 2 x 10^13 ohms/cm^3. CWR/WFR. 26/2/1935. | ||