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).
Letter from H.D. Symons & Co. Ltd. discussing conductance test results on waxed paper.
| Identifier | ExFiles\Box 61\1\ scan0170 | |
| Date | 23th March 1931 | |
| H.D.S. continuation 2. Rolls Royce Limited. 23rd March, 1931. There is no doubt that the conductance is affected by the voltage of test, but we should not expect a very great difference between conductance tests made at 300 and 500 volts, unless the number of layers has an influence on the results. We found that the results are very greatly affected by the surface moisture, and even heating for a period of as short a time as 1 1/2 minutes at 100°C with top electrode removed gave very much improved conductance figures. The following give the results which we obtained in this way with the paper we originally delivered to you, and which was rejected by you:- 1. Top electrode in position immediately specimen placed in oven ...................0.0238 micromhos. Temp. 100°C. 2. Top electrode in position 1 minute after specimen placed in oven...............0.0010 " Repeating these tests on the new paper we sent to you we got the following figures:- 1. Top electrode in position immediately specimen placed in oven.................. .0005 micromhos. 2. Top electrode in position 1 minute after specimen placed in oven.................. .0008 " We would be glad to have your comments on the relative value of your method of test by testing 15 layers at a high voltage and ours of testing a single layer at a lower voltage. In the meantime we are continuing our work on the raw materials and method of manufacture used in the production of this waxed paper. Yours faithfully, H.D. SYMONS & COMPANY LIMITED. Harold D.{John DeLooze - Company Secretary} Symons. | ||