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).
Log sheet detailing the results of trials conducted on a speed indicator tester.
| Identifier | ExFiles\Box 33\5\ Scan085 | |
| Date | 17th May 1928 | |
| TRIALS OF SPEED INDICATOR TESTER. Date. | Approx. time period. | Time under 10 mins. for 3000 counter revs. (secs). | % fast. | Frequency. 18-5-26 | 5-15 to 5-25 | correct | correct | correct 19-5-26 | 2-40 to 2-50 | +1.8 | .30 | 50.15 24-8-26 | 2-45-2-55 | +1.4 | .28 | 50.14 24-8-26 | 3-0-3-10 | +1.2 | .20 | 50.10 17.5.28. | ||