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).
Calibration results and findings for a Cambridge Millivolt Potentiometer.
| Identifier | ExFiles\Box 165\3\ img052 | |
| Date | 28th April 1924 | |
| x925 6033. To H.L. from E.F.C. EFC3/T28.4.24. X.975 - RE CAMBRIDGE MILLIVOLT POTENTIOMETER We have carefully tested and calibrated this instrument on both ranges and have seen no sign of anything wrong. The calibration of the instrument we find to be as follows :- 18 Milli-volt range. Subtract 1.1% from all readings, result then correct to within ± .8%. Scale proportionality very fair. 190Milli-volt range. Subtract .7% from all readings, result then correct to within ± .3%. Scale proportionality good. It will be seen that the calibration of the 90milli-volt range is distinctly better than that of the 18. We herewith return the instrument but may like to borrow this sometime soon in connection with some temperature measurements of valves, utilising EFC. nickel-iron thermo couple. | ||