Keller M5 series sensors for static and highly dynamic measurements

Keller has released the M5 series sensors for static and highly dynamic measurements. The rear of the silicon sensor is soldered to a supporting element designed for good fluid dynamics, which in turn is secured flush at the front of the pressure connection.

The design enables good decoupling of mounting forces and structure-borne vibration, extensive media compatibility and the durability offered by the antioxidation coatings. Other features include overpressure protection of up to five times the measurement range and a pressure connection with an external thread of 5 mm for installations in space-limited locations.

The pressure sensors are intended for operating temperatures between -40 and +180°C with a narrow total error band of ±1%. Without the remote signal converter, they come with a typical output signal range of 80 mV (based on a 1 mA supply) and an individual calibration certificate. The 3, 10 and 30 bar measurement ranges are available for absolute pressure measurements.

To avoid reduction in the piezoresistive pressure sensor’s dynamic range of 50 kHz, Keller did not digitise the measurement signal - instead, the purely analog signal path is adjusted in real time via the compensation electronics, which are controlled by a microprocessor. This ensures the output signal, amplified to 0-10 V, retains the full dynamic range of the sensor signal. The measurement system, consisting of the pressure sensor and signal converter, undergoes end-to-end calibration once the user-specific parameters have been determined. The operating temperature range of -40 to +125°C for the remote electronics satisfies the demands required by engine test benches.

The thermally ultra-robust pressure transducers in the series support high-precision static and dynamic measurements up to a bandwidth of 50 kHz and at working temperatures of up to 200°C at the pressure sensor. With its M5 connection thread, the remote pressure sensor - which contains no oil and associated isolation diaphragm and no sealant or adhesive in contact with the media - is suitable for taking highly dynamic measurements at close proximity. It can do this at the very thin pipes used in engine test benches, in wind tunnels or during turbine blade tests.