Compact OEM force sensors allowing flexibility in design and application

Optimized to cover a broad force range and to minimize hysteresis

Pewatron introduces two new OEM force sensors which are perfectly suited for mobile dosage of medicine and a variety of other safety critical applications including pump regulation, robotics, weighing, automation and indirect pressure & flow measurement. The sensors can be used in variety of industrial segments, such as medical, semiconductor and biochemistry industries. Pewatron offers standard OEM, off-the-shelf force sensors. The CentoNewton OEM force sensor measures compressive forces in the range 10…200 N (1 to 20 kg @ 1 G). The MilliNewton OEM force sensor measures forces in the range 400…2000 mN.

The CentoNewton sensor is a simple and low-cost solution for the integrated measurement of medium forces, and for applications not necessitating the precision of a machined load cell. The force is measured by the “double ring” flexion principle. The integrated conditioning electronics delivers an adjusted and amplified ratiometric voltage output (0.5…3.0 V) that is linear with the applied force. The temperature range for operation is 0...70°C. The force sensor is not temperature compensated, but the temperature coefficients are typically well below 0.1 %/K. The CentoNewton draws less than 3 mA during operation, which is sufficiently low to be designed in for battery operations. One very big advantage of the “double ring” flexion principle is the reduced hysteresis of the force sensor, which is minimized due to a two-ring support principle.

The MilliNewton force sensor is optimized for measurement of small forces. The force is measured through bending of a cantilever beam, which carries a piezoresistive bridge. The electronics on the base carrier substrate deliver an adjusted ratiometric voltage output (0.5…3.0 V) that is linear with applied force. The accuracy of the zero-point offset and the span is better than 1 % FSO and the temperature coefficients of the zero-point offset and the span is typically better than 0.02 % FS/K (0…70°C). The MilliNewton also draws less than 3 mA during operation, making it also very useful in battery operated devices.

Both of the force sensors can be used to regulate the dosage of medicine, either by single use of one of the sensors or with the use of both of the sensors in the same device for higher accuracies and in order to cover a large range of medicine from a few ml up to liters. Generally speaking, most mobile devices (and not limited to medical applications) with dispensing of fluids or gasses can benefit from both the force sensors for optimal dosage and end-of-media control. Some applications use the force sensors for detection of clogging in a flow system. For this application, the force sensor secure a reliable flow by making sure that no pressure or force is building up in tubes and pumps.