The N.A.C.A. optical engine indicator

Tozier, Robert E
naca-tn-634
1938


An optically recording engine-pressure indicator of simple and rugged construction has been developed for use in high-pressure and high temperature combustion research. This instrument is of the diaphragm type and has a natural frequency of about 10,000 cycles per second.

An Adobe Acrobat (PDF) file of the entire report:
http://naca.central.cranfield.ac.uk/reports/1938/naca-tn-634.pdf