Static and Dynamic Calibration of Pressure Transducers at Elevated Temperatures

Abstract

The Air Force conducts tests requiring measurement of high dynamic pressures in high-temperature environments. Such tests require measurement of dynamic pressures created by jet engines, turbulent air-flow along hot areas of aircraft structures, and acoustic levels in Air Force test chambers such as acoustic chambers, wind tunnels, and engine test stands. Several commercial industries also have requirements for high-temperature dynamic measurements. To address these Air Force needs for dynamic pressure measurements at high temperatures, the Structures Division of the Flight Dynamics Directorate of the Wright Laboratory evaluated dynamic pressure transducers for use in extreme acoustic and thermal environments. Transducer manufacturers were surveyed and three off-the-shelf pressure transducers capable of measuring dynamic pressures at extreme environments were identified. The first model measures up to 194 dB(A) and operates up to 260°C (500°F). This model has an extended operating temperature up to 1649°C (3000 °F) when used with a water-cooled jacket. The second model is an air-cooled transducer advertised to operate up to 593°C (1100°F). The third model is a water-cooled transducer advertised to operate up to 2802°C (5075 °F). Two of the models have low sensitivity and thus require more output amplification. These two models are also larger and require larger mounting holes. The transducers were evaluated at various static pressures, acoustic levels, and temperatures. This paper describes the procedures used to calibrate these transducers up to a 172-dB sound pressure level (SPL) and a temperature of 732°C (1350°F). The results for these transducers are summarized for different static pressures, operating SPLs, and temperatures.