CHARACTERISATION OF SURFACE ACOUSTIC WAVE SENSORS FOR STRAIN MEASUREMENT
Abstract
Strain gauges are applied in a wide industrial range. Sometimes, their application can be very difficult or even impossible due to a lack of space or the requirement of an electronic connection with a processing unit. To avoid these problems, the SAW Components Dresden GmbH has developed a new sensor system for strain measurements. It is capable to transmit the measured signal directly from the sensor to the processing unit without any need of wires. In comparison to the strain gauge technology, the deformation on the components surface is not determined by a change of the sensors electrical resistance. Instead the SAW device measurement principle is based on the propagation of surface acoustic waves between two interdigital electrodes. The resonance frequency of the standing wave can be determined using an interdigital transducer. This resonance frequency is directly related to the tension of the sensor and decreases with increasing strain. The coupling factor between the modification of the resonance frequency and the tension of the component, the sensor is mounted to, can be described by the sensitivity, similar to the gauge factor of strain gauges.<BR />The sensitivity of the SAW sensors is mainly affected by the transmission of strain in the intermediate layer between component and substrate as well as the strain transmission of the piezoelectric crystal itself.
Event details
- Event
- TC15 Youth Symposium 2011
- Technical Committee
- TC15
- Place
- Chemnitz, GERMANY
- Time
- 25 May 2011 - 28 May 2011