Page 899 - Basic Electrical Engineering

Figure 12.16 Piezoelectric pressure transducer

Figure 12.17 Measurement of pressure by a photoelectric transducer

12.13 PHOTOELECTRIC TRANSDUCER

This is an optical transducer which uses a photo tube and a light source. The

amount of light falling on the photosensitive cathode of the photo tube is
varied so that the anode current is changed. Fig. 12.17 shows a light source

and a photo tube used for the measurement of pressure. The output voltage
depends upon the amount of light falling on the tube through the window.