farnboro engine indicator

[monty37]

what is a farnboro engine indicator and what is it used for?

[AlephZero]

For an IC engine, an "indicator diagram" is a plot of pressure against volume in the cylinder over the engine cycle, which measures the work done by the gas.

The Farnborough indicator was an early mechanical device to measure this, before electronic pressure transducers etc were available.

Googling for "Farnborough Indicator" will find you more details (note the correct spelling).

[monty37]

I did find details but the principle ,experimental setup etc are not explained ,is this
indicator obsolete now ?

[brewnog]

Everyone uses pressure transducers now, these are read at high speed and correlated against crank angle electronically to give an indicating diagram.