October 18, 2012. Kistler, a supplier of precision sensors, systems, and instrumentation for the dynamic measurement of pressure, force, torque, and acceleration, has announced the availability of lightweight miniature accelerometers for automotive component durability testing.
Throughout all phases of the new vehicle R&D and manufacturing process, Kistler accelerometer technologies are used to test the critical automotive components found on engine mounts, rear and front suspensions, steering assemblies, exhaust mounts, bushings, transmissions, and drivelines, as well as within fully instrumented new vehicle prototypes during both on-road and laboratory simulated testing. These transducers play a vital role in helping automotive engineers to better understand how interrelated vehicle components and systems structurally behave over time, as well as within various environments.
Miniature automotive component durability testing is often conducted inside of test-chamber environments, where reliability and performance over a component’s full useful service life and temperature are simulated. These tests are commonly known as highly accelerated life test (HALT), highly accelerated stress screening (HASS), and environmental stress screening (ESS). Kistler Type 8703A and 8705A PiezoStar accelerometers are typically specified for HALT/HASS/ESS and other related areas of automotive evaluations. The accelerometers are used inside of the test chamber, as it runs through temperature changes, and on components and subassemblies themselves. Another choice is the Kistler Type 8766A family of lightweight, miniature triaxial PiezoStar accelerometers. The advantages offered by these sensors lie in their capability to provide simultaneous shock and vibration measurements in three orthogonal axes with stability and performance, particularly in environments where lowest possible mass with highest possible frequency response are required.
Available in measurement ranges of ±50, ±250 and ±500 g, the low-noise Type 8766A incorporates Kistler’s own proprietary PiezoStar shear element quartz crystal technology, together with high-gain internal hybrid microelectronics, to produce a sensor that can reliably operate over a wide dynamic frequency range, with very low sensitivity variations over its operating temperature range and high immunity to base strain errors. Piezoelectric sensing elements of the Kistler Type 8766A are housed within a welded, hermetically sealed, low-mass titanium housing, finishing in a ¼-28 automotive industry standard connector (other connector types available upon request). Additional special features of the Type 8766A that make them especially suitable for automotive component durability testing are their full calibration to 15 kHz and stud mounting on all three axes, with the added ability to measure low-frequency vibration to 0.5 Hz. Units also feature optional Transducer Electronic Data Sheet capabilities per IEEE 1451.4 (TEDS V1.0, with supported templates T05 and T06) for larger channel counts. For high-temperature applications, a +165°C version allows the sensors to maintain accurate readings under extreme conditions, with minimal sensitivity shift over the full operating temperature range.
Another choice is the Kistler Type 8763B, a miniature triaxial IEPE (voltage output) accelerometer, offering simultaneous shock and vibration measurements on three mutually perpendicular axes with optional TEDS. Available in ranges from ±50 to ±2000 g and in sensitivities from 100 to 2.5 mV/g, the low-noise Type 8763B incorporates Kistler’s shear element sensing technology, ensuring high base strain immunity, packaged in a lightweight, hermetically sealed titanium housing with choice of an automotive testing industry standard 4-pin ¼-28 or M4.5 mini four-pin connector. Units offer option of either adhesive mounting or three 5-40 threaded holes for flexible stud mounting, fully utilizing each cube mounting side and facilitating calibration of each orthogonal axis. Models are rugged to ±5,000 g shock and feature a wide per axis frequency response, making them ideal for the automotive component durability testing of lightweight structures, particularly within larger channel applications.
For high-precision, low-frequency structural analysis and vibration measurements of automotive components, subassemblies and other critical structures, K-Beam MEMS variable capacitance accelerometers are specified. The K-Beam family is offered in ranges from ±2 to ±200 g and with frequency response from DC (steady state) to 1000 Hz (±5%). These accelerometers are available in single-axis (Type 8315) or triaxial (Type 8395A) versions and incorporate the use of a MEMS variable capacitance sensing element, consisting of a small inertial mass and flexure element sandwiched between two electrodes. As the mass deflects under acceleration, the capacitance between the sensing element and electrodes changes, then converted to a proportional voltage by its internal analog signal conditioner. All sensors offer excellent thermal stability and reliability over temperatures of -55° to +125°C, with ±6,000 g pk shock survivability. The single axis Kistler Type 8315 features a 25.4-mm square footprint and is powered by a single wide range supply between +6 and +50 VDC, with three unique housing (AC, TA, TB) options that determine available output signal formats. The AC option features lightweight, hard anodized aluminum housings with environmental sealing, integral ground isolation, epoxy seal and integral PVC cable, and a maximum operating temperature of +85°C. TA and TB options are offered with identical output signal formats as the AC version, yet include a temperature output, if external compensation is desired.
The Type 8395A triaxial version is designed to simultaneously measure acceleration and low-frequency vibration in three orthogonal axes (x, y and z), within a compact 21.6-mm cube footprint. The output format of the Type 8395A is bipolar at 0±4V and provides a high-sensitivity, low-noise signal, compatible with a variety of data acquisition devices. Sensing elements and integral electronics are housed within a lightweight, welded titanium housing with a specially designed, miniature circular 9-pin connector for a fully hermetic design. It is powered by a single wide range +6- and +50-VDC supply. In the event that external temperature compensation is desired, a temperature output is provided, in addition to output signals. Ground isolation is obtained by mounting the sensor using off-ground accessories or by adhesively mounting to the test object.