Farnborough electric indicator

Made:
1954 in Glasgow
Farnborough electric indicator

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Farnborough ("Farnboro") electric indicator, made by Dobbie McInnes Ltd.

Measures cylinder pressure by recording the balance point, the time at which a certain cylinder pressure balances standard air pressure. The record or diagram is obtained by rotating a sheet of paper at engine speed or one-half engine speed in the air-gap such that the spark in going to earth must perforate this paper.

Details

Category:
Motive Power
Object Number:
Y1988.128
Materials:
metal (unknown) and wood (unidentified)
Measurements:
overall: 460 mm x 610 mm x 315 mm,
type:
electric indicator
credit:
Gift of Central Electricity Generating Board