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 behaviour and testing of different oil level indicators in aerated oil.
| Identifier | ExFiles\Box 6\6\ 06-page022 | |
| Date | 30th November 1934 | |
| -2- Behaviour in Aerated Oil. Commencing with a known quantity of oil (9 pts.) in the sump, the whole of it was whipped into foam. This of course increased the volume of the sump contents, and increased the "fixed" indicator reading (to 12 pints), but providing the B.W.P. and the R.R. indicators were allowed to follow their normal courses, they registered - within 1 pint - the correct oil - not foam - level. The sump contents were "frothed up" before each test to prevent false readings due to the oil settling down. If, with the pump running, the B.W.P. was lifted up, and then allowed to resettle, it returned to its original position, but, if it was further immersed in oil it "stayed put" whereas when the froth was not in circulation it returned, slowly, to within 1 pint of its correct oil level. The R.R. indicator always returned to the oil level, whether depressed to minimum, or lifted to maximum position. When the foam was allowed to de-aerate, all three indicators tallied. In order to aerate the oil to any degree, it was necessary to use cold oil, and to restrict the delivery. With hot oil, only a very thin layer of foam was produced - not sufficient to upset the indicator readings. The three types of indicator are illustrated in Hs.{Lord Ernest Hives - Chair}1627. Hs{Lord Ernest Hives - Chair}/W.Bell. | ||