CONTRIBUTION TO THE DEVELOPMENT OF A SMART SENSOR USING EDDY CURRENTSFOR MEASUREMENT OF DISPLACEMENT

A smart sensor is a device whose response takes into account and corre cts for environment variables. This study shows that such a device can be produced. The major influential variables studied were temperature and humidity. The sensor was a sensitive coil inserted in an LC oscil lator circuit. Oscillator operation was improved to obtain sufficient stability. Data were acquired on a testbench. Although the measurement s were distorted by many phenomena (noise, dilation and so on) it was quite possible to design a displacement measurement smart sensor, base d on several theoretical models. They predict a frequency response ver sus distance and temperature. The experimental results were in good ag reement with the models.