Engineering topics
Publications and source records attributed to Egger, R. L..
Capacitive pressure transducer operates continuously at temperatures as high 1,2000 F, and has been evaluated over full-scale differential pressure range of + or - 10 psi (69 x 1000 N/sq m).
High temperature pressure transducers capable of continuous operation while exposed to 650 C were developed and evaluated over a full-scale differential pressure range of + or - 69 kPa. The design of the pressure transducers was based on the use of a diaphragm to respond to pressure, variable capacitive elements arranged to operate as a differential capacitor to measure diaphragm response and on the use of fused silica for the diaphragm and its supporting assembly. The uncertainty associated with measuring + or - 69 kPa pressures between 20C and 650C was less than + or - 6%.
Improved bridge-compensation circuit saves considerable time in balancing bridge and wiring it for temperature compensation. Large bridge-balance compensation is made before temperature cycling and small adjustments are made with different type of wire.
Capacitive strain gage and signal conditioning system measures stress-induced strain and cancels thermal expansion strain at temperatures to 1,500 F (815 C). Gage does not significantly restrain or reinforce specimen.
Strain gage for detecting and measuring mechanical strain in thermally strained specimens
High temperature thermal null strain gage with sensing unit and electronic control unit to measure mechanical strain in terms of induced thermal strain