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 on the accuracy and performance of a Moving Iron Ammeter.
| Identifier | ExFiles\Box 168\5\ img236 | |
| Date | 16th January 1932 | |
| Copy for Files. MOVING IRON AMMETER. Accuracy correct, in both directions. Insulation correct. Reasonably damped. Reads .5 amp lower in vertical position than when horizontal. Accuracy maintained at 35°C. After passing 30 amps through instrument for three seconds in both directions, the zero moved .5 amp in charge direction. On retesting for accuracy the readings were found to be inconsistent owing to slight stickiness of the needle. After passing 30 amps through the instrument for three seconds in both directions the readings obtained were .3 amp high for every 5 amps for a 10 amp deflection the instrument showed 11 amps, for 15 amps the instrument read 15.5, these readings were taken in the charge direction. In the discharge direction, for readings from zero to 10 amps the instrument was accurate, at 15 amps the reading was .5 amp high. J.W. | ||