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 accuracy of Simms Magnetic Petrol Gauges and a proposal for a more intelligible marking system.
| Identifier | ExFiles\Box 75\2\ scan0150 | |
| Date | 24th June 1920 | |
| X.4159 To BY.{R.W. Bailey - Chief Engineer} from Hs.{Lord Ernest Hives - Chair} c. to Sa. c. to EF. RFe HsL/LG.24.6.20. 2 X.4159 RE SIMMS MAGNETIC PETROL GAUGES. X.1798 X.3481 We do not consider that the Simms Magnetic Petrol Gauges are sufficiently accurate to record the correct quantity of petrol in the tank. From our experience with these gauges, we should expect an error of plus or minus one gallon in the reading. We do not know of a gauge that will record accurately the exact amount of petrol. We consider that instead of marking the gauges off to show the accurate gallons, they should be marked - empty, quarter-full, half-full, three-quarter-full and full. It might be an advantage that on the empty mark there should be two gallons of petrol remaining in the tank as the reserve. Another advantage of marking it in this way is, that no matter what country the Car was in it would be intelligible. It is no use having a gauge marked in gallons for France or Russia etc. When Mr. Royce started making a gauge, his intention was to mark it in this way because he did not think it was practicable to make a gauge sufficiently accurate to read the gallons. HS.{Lord Ernest Hives - Chair} E C JUN REC. | ||