New Miniature Triaxial Accelerometer for High Temperature Applications

The new Type 8766A lightweight, triaxial accelerometer from Kistler Instruments uses the, patented PiezoStar® crystal developed by Kistler to provide ultra-stable performance with very little sensitivity deviation with temperature changes. Over a temperature range of -50°C to +165°C a PiezoStar® sensor has a sensitivity deviation with temperature which is over thirty times better than a similar quartz sensor. The Temperature Coefficient of Sensitivity of a quartz triaxial accelerometer is 0.18 %/°C, compared with only 0.005 %/°C for a 250g measurement range for the new PiezoStar triaxial accelerometer.

The new accelerometer has been designed specifically to bring these unique properties to applications demanding high accuracy measurements in varying temperature up to 165°C. The small cubical, hermetic titanium housing has threaded mounting holes on each of three sides to facilitate calibration and simplify installation for tests whilst the low mass of only 4g reduces any influence on the test structure. The Kistler PiezoStar® shear element design provides a flat frequency response over a wide operating frequency range and extremely low sensitivity to temperature changes.

The IEPE sensor combines the PiezoStar® crystal with high gain, integral, hybrid microelectronics to achieve very low sensitivity variation over the wide operating temperature range, compared to other sensing element designs, and high immunity to base strain errors. The Transducer Electronic Datasheet (TEDS), embedded in the chips integrated within the IEPE sensor, enable data acquisition systems to automatically recognise the sensor specification and so reduce set up time, minimise risk of human errors and eliminate the need for manual point-to-point connection identification.

Five variants cover the measurement range from ±50g to ±1,000g all with a 100% overload capability plus a high temperature option for temperatures of up to 165°C. In contrast to ceramic and quartz, the extremely stiff piezoelectric crystal sensing element offers a flat frequency response with no slope across the entire useable frequency range of 0.5 to 20,000 Hz.

The accelerometer uses a welded titanium construction for low mass and an industry standard 4 pin connector, as well as a mini 4 pin connector option for lower mass and wider frequency operation. All variations provide reliable measurements and long-term stability, especially at higher operating temperatures. The miniaturised lightweight measuring element in a hermetic titanium housing which has threaded mounting holes on each of the three axes to simplify cable connection and minimise unwanted cable loops. A range of ground isolated mounting bases are available with adhesive, threaded and magnetic mounting options and an integral silicone cable variant is available for underwater vibration testing at up to 10 bars (150 psi).

With its extremely wide and flat frequency response, the unique Type 8766A accelerometer from Kistler instruments is ideal for use in modal and durability testing applications at widely varying temperatures.