Kistler unveils advanced version of their smallest water-cooled miniature cylinder pressure sensor

Source: press release, 25 January 2022

M8 miniature cylinder pressure sensor: Besides its measurement precision, the sensor offers engineers various installation options
M8 miniature cylinder pressure sensor: Besides its measurement precision, the sensor offers engineers various installation options (illustration: Kistler)

With the M8 miniature cylinder pressure sensor (6041C), Kistler launches the smallest water-cooled cylinder pressure sensor. It incorporates state-of-the-art PiezoStar crystals and yields precise measurement results thanks to improvements to its design and manufacturing process. This versatile, reliable cylinder pressure sensor is the solution of choice for thermodynamic investigations in the engine development process, where overall accuracy is of highest priority.

Combustion engines are set to maintain a position in future propulsion concepts for many years to come, but new alternative fuels will challenge engine developers. Kistler’s response: a portfolio of highly advanced sensors that provide maximum support for the development process.

The new 6041C miniature cylinder pressure sensor is the third generation of Kistler’s smallest water-cooled sensor (size: M8) and features minimal sensor-to-sensor deviation during combustion pressure measurements. Thanks to the small linearity deviation, engineers are able to yield accurate measurement data at all loads.

Improved thermodynamic behavior creates more stable measurements within the application temperature range of 50 ± 30° C, even during thermal changes in the combustion chamber. Moreover, its thermal shock error is minimal, ensuring mean effective pressure (MEP) accuracy under all conditions. The miniature sensor features an optimised cooling flow around the measuring element to enhance its stability over long-term measurements and grants a longer service life without losing thermodynamic accuracy over time.

A robust sensor for diverse applications
Compared to uncooled sensors, water-cooled sensors have the advantage that they can be either recess-mounted or flush-mounted, even when subjected to high thermal loads. Thanks to the latest PiezoStar crystal technology and an advanced measuring element coupled with improvements to the production process, they provide measurement results with maximum accuracy. These advances also give the 6041C miniature cylinder pressure sensor higher natural frequency and excellent thermal stability, so the sensor is optimised for gas exchange analysis tasks.

Like its predecessors, the 6041C cylinder pressure sensor requires only little space and can be mounted in a sleeve or directly into bore holes starting from 12mm diameter. The sensor is compatible for mounting with its predecessors 6041B and 6041A, and the uncooled variants 6045A, 6045B and 6044A. The sensor comes with a mounted cable, and optional PiezoSmart sensor detection.

Highest precision for engine developers
Roger Leutwyler, Product Manager for piezoelectric cylinder pressure sensors at Kistler, comments, “High sensitivity, high natural frequency, a low thermal shock error and outstanding zero-point stability: these advantages make our new 6041C cylinder pressure sensor deliver measurement results with the highest accuracy. As a miniature sensor with an M8 mounting thread, it is particularly suitable for compact multi-valve engines where space is limited – and obviously, its benefits also come into play whenever precision and long-term stability are critical factors.”