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).
Test report for a Magneto Speed Indicator, detailing resistance adjustments and reading corrections.
| Identifier | ExFiles\Box 34\2\ Scan053 | |
| Date | 12th October 1922 | |
| RR 238 (300 Bks.) (SF 152. 6-11-18.) MP 197880 X.2238 ROLLS-ROYCE LIMITED. INSTRUCTIONS. To EFC Order No. AB.56. Customer's No. 1 X 2238 Magneto Speed Indicator. The resistance coils of the first machine, mentioned in the previous report on the above, AB55, 5-X-22, have been used in conjunction with the second machine, operating on the same Weston instrument. The resistance was adjusted so that the reading was correct at 1000 rpm and the correction necessary for the rest of the scale was then found with the results shown below. Reading | Speed | Ratio | % correction 500 | 495 | .990 | +1.0 790 | 795 | .994 | -.6 1000 | 1000 | 1.0 | 0 1250 | 1285 | 1.028 | +2.8 1500 | 1580 | 1.052 | +5.2 2000 | 2150 | 1.075 | +7.5 Signed: A.{Mr Adams} Allen This Sheet must be filed on completion of the work. | ||