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Test report on speedometer lag during acceleration at different speeds.


Identifier  ExFiles\Box 8\2\  02-page36
Date  27th January 1923 guessed
  
TESTS CARRIED OUT TO DETERMINE IF THE SPEEDOMETER SHEWS ANY LAG IN FOLLOWING UP INCREASE OF SPEED.

Third speed.
A. {Mr Adams} Readings. Start 10 m.p.h. Finish 28 m.p.h. Distance 177 ft.
By time 3.85 f.p.s²
By speedometer 3.92
Error 2%
B. Readings. Start 10 m.p.h. Finish 29 m.p.h. Distance 192 ft.
Time 6.8 secs.
By time 3.92 f.p.s²
By speedometer 3.96 f.p.s²
Error 1% +
C. Readings. Start 10 m.p.h. Finish 28 m.p.h. Time 6.4 secs.
Distance 178 ft.
By time 4.14 f.p.s²
By speedometer 3.92 f.p.s²
Error 5% -
D. {John DeLooze - Company Secretary} Readings. Start 10 m.p.h. Finish 29 m.p.h. Time 6.8 secs.
Distance 192 ft.
By time 3.988 f.p.s²
By speedometer. 3.97 f.p.s.²
Error 4% -
Average error for accns. of 4 f.p.s. = 1% too little by Speedometer.

Second speed.
A. {Mr Adams} Readings. Start 10 m.p.h. Finish 28.5 m.p.h. Time 6.6 secs.
By time 4.3 f.p.s²
By speedometer 4.06 f.p.s²
Error 6% -
B. Readings. Start 10 m.p.h. Finish 29 m.p.h. Time 6 secs.
Distance 178 ft.
By time 4.7 f.p.s²
By speedometer 4.5 f.p.s²
Error 5% -
C. Readings. Start 10 m.p.h. Finish 30¼ m.p.h. Time 6 2/5 secs.
Distance 192 ft.
By time 5 f.p.s²
By speedometer 4.68 f.p.s²
Error 7% -
Average error for accelerations of 4.5 f.p.s.s. is 6% too little reading by speedometer.
  
  
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).


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