High-Temperature, up to 815 °C, Frequency Bandwidth 12 kHz (± 3 dB), Piezoelectric Accelerometer Operating With Remote Charge Converter

Design of the extremely high-temperature, up to 815 °C, piezoelectric accelerometer with extended frequency bandwidth is presented in this letter. The accelerometer incorporates a high-temperature, up to 815 °C, piezoelectric (HTPE) transducer connected to a patented remote charge converter (RCC) via a high-temperature shielded hardline cable. The HTPE transducer contains a Parker Meggitt MC2 high-temperature crystal in shear mode as a sensing element. The RCC suppresses the transducer natural resonance resulting in extending its frequency bandwidth from 3 to 7 kHz at the level of ±5% and from 6 to 12 kHz at the level of ±3 dB. The accelerometer including RCC has a sensitivity of 3 mV/G and a frequency range from 3.5 Hz to 12 kHz at the level of ±3 dB. RCC's gain is fixed and equals 1 mV/pC. It can operate over a constant current range of 8 to 20 mA and at temperatures from −10 °C to +100 °C. RCC features small size and weight, two-wire output, and allows a transducer to have a resistance as low as 10 kΩ that typically takes place at extreme high temperatures. The small size (about 24 × 14 mm) and lightweight (30 g) of the HTPE transducer allows installation in narrow locations with minimal structural support.