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Armentrout, E. C.

Publications and source records attributed to Armentrout, E. C..

Fatigue strength testing employed for evaluation and acceptance of jet-engine instrumentation probes

This report outlines the fatigue type testing performed on instrumentation rakes and probes intended for use in the air flow passages of jet-engines during full-scale engine tests at Lewis Research Center. Included is a discussion of each type of test performed, the results that may be derived and means of inspection. A design and testing sequence outlines the procedures and considerations involved in the generation of suitable instrument probes.

Armentrout, E. C.↗

Pressure instrumentation for gas turbine engines - A review of measurement technology

Many types and designs of pressure measuring instrumentation are used during the development and testing of gas turbine engines. This paper provides an overview of more commonly available pressure transducers and their characteristics. Probe designs for use in both steady-state and dynamic pressure measurement systems are reviewed. Techniques used to qualify instrument probes and the methods used to calibrate pressure transducers during engine testing are described.

Armentrout, E. C.↗

On-line calibration of high-response pressure transducers during jet-engine testing

Current jet engine testing is concerned with the effect of inlet pressure and temperature distortions on engine performance and involves the use of numerous miniature pressure transducers. Despite recent improvements in the manufacture of miniature pressure transducers, they still exhibit sensitivity change and zero shift with temperature and time. To obtain meaningful data, a calibration system is needed to determine these changes. A system has been developed which provides for computer selection of appropriate reference pressures selected from nine different sources to provide a two- or three-point calibration. Calibrations are made on command, before and sometimes after each data point. A unique 'no leak' matrix valve design is used in the reference-pressure system. Zero-shift corrections are measured and the values are automatically inserted into the data reduction program.

Armentrout, E. C.↗

On-line calibration of high-response pressure transducers during jet-engine testing

Jet engine testing is reported concerned with the effect of inlet pressure and temperature distortions on engine performance and involves the use of numerous miniature pressure transducers. Despite recent improvements in the manufacture of miniature pressure transducers, they still exhibit sensitivity change and zero-shift with temperature and time. To obtain meaningful data, a calibration system is needed to determine these changes. A system has been developed which provides for computer selection of appropriate reference pressures selected from nine different sources to provide a two- or three-point calibration. Calibrations are made on command, before and sometimes after each data point. A unique no leak matrix valve design is used in the reference pressure system. Zero-shift corrections are measured and the values are automatically inserted into the data reduction program.

Armentrout, E. C.↗

Signal conditioner for potentiometer type transducers

Low cost method is described for signal conditioning of pot-type transducers utilizing printed circuitry. Conditioner fits into standard rack, accommodates 56 channels, and can be operated by one attendant.

Armentrout, E. C.↗

Cooled miniature pressure transducers effective at high temperatures

Miniature pressure transducers in compact water-cooled mounts are placed in hotter and more confined environments than previously possible. It quantitatively measures high frequency total pressure fluctuations resulting from rotating stall in an axial flow engine compressor.

Armentrout, E. C.↗