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).
Specification for the inspection and testing of a chassis ammeter.
| Identifier | ExFiles\Box 168\5\ img220 | |
| Date | 28th October 1931 | |
| X6122 CHASSIS AMMETER. SPECIFICATION OF INSPECTION & TEST. (1) The instrument should be tested by means of a twelve volt battery and sensitive voltmeter to ensure that the electric circuit through the instrument is insulated from the case. (2) Check the accuracy of the instrument at one reading between ten and fifteen amperes on each side of the scale against a reasonably accurate box type instrument, and note if there is any tendency to sticking of the indicating needle at any point of the scale. Also note if similar readings are obtained with the instrument vertical and horizontal. Ascertain also if the instrument is reasonably dead beat. (3) Re-check the instrument as in (2) with the instrument raised to a temperature of 35°C. (4) Pass a current of 60 amperes through the instrument for three seconds in one direction and then for three seconds in the other direction, and note if this causes any apparent mechanical irregularity. Increase the current to 90 amperes and repeat. (5) Re-check the instrument as in (2) to see that its calibration has remained of a similar degree of accuracy. Hs{Lord Ernest Hives - Chair}/Wst. | ||