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 from trials of a speed indicator tester.
| Identifier | ExFiles\Box 33\5\ Scan084 | |
| Date | 17th May 1926 | |
| TRIALS OF SPEED INDICATOR TESTER. Date. | Approx. time period. | Time under 10 mins. for 3000 counter revs. (secs). | % fast. | Frequency. 10-5-26 | 11-55 to 12-5 | + 1.5 | +.25 | 50.12 10-5-26 | 3-25 to 3-35 | + 3.0 | +.50 | 50.25 11-5-26 | 10-45 to 10-55 | + 2.0 | +.33 | 50.16 11-5-26 | 11-30 to 11-40 | + 2.1 | +.35 | 50.17 11-5-26 | 12-30 to 12-40 | + 2.1 | +.35 | 50.17 11-5-26 | 4-50 to 5-0 | + 1.5 | +.25 | 50.12 12-5-26 | 10-0 to 10-10 | + 2.6 | +.43 | 50.22 12-5-26 | 12-25 to 12-35 | + 1.2 | +.20 | 50.10 13-5-26 | 9-20 to 9-30 | Correct | Correct | Correct 14-5-26 | 3-20 to 3-30 | Correct | Correct | Correct 17.5.26. | ||