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 a Park Royal Ammeter, detailing initial issues, re-testing, and subsequent performance.
| Identifier | WestWitteringFiles\R\2December1927-February1928\ Scan213 | |
| Date | 28th February 1928 | |
| To R.{Sir Henry Royce} from EFC. c. BJ. E.{Mr Elliott - Chief Engineer} c. By.{R.W. Bailey - Chief Engineer} ORIGINAL EFC2/T28.2.28. PARK ROYAL AMMETER. V4670 We have had on test since June last an ammeter type MC.2.F. made by the Park Royal Company. A report JC.90 of one of my assistants dated 18.6.27 on this instrument reads as follows :- "This instrument is fitted with the makers' patent "Pivaspring" and is claimed to be immune from shock and vibration. The ammeter has a good appearance and also a good black finish. It reads correctly on each side of the scale and readily responds to a slight variation of current to the extent of .10 ampere. The instrument is more dead-beat than either the Weston or Elliott, giving one oscillation which covers half a division. The instrument was then overloaded with a current of 60 amperes for a period of 3 seconds in each direction, and afterwards tested for accuracy and movement. It was found to read correctly but the needle had a tendency to stick at about 1 div. each side of the zero and would not respond to a current of 1 ampere or less until the ammeter was tapped. This does not speak too well of the patent pivot. It should be noted that the dial is not marked "charge" and "discharge". EFC. instructed instrument to be re-tested owing to sticking of needle, as sticking apparently disappeared. G.J's further report:- The above tests were repeated, and the instrument passed the tests satisfactorily there being no signs of any sticking whatever. Ammeter fitted to 8-EX. 5.7.27. EFC/G.Johnson. The instrument having been put on 8-EX has done 8750 miles satisfactorily and is still giving, so far as our observation can go, satisfactory operation. Contd. | ||