4.2 Classifications of transducers Physical-property-type transducers based on the change in physical properties of its sensing element material to realize signal conversion Pressure accelerometer: based on the piezoelectric effect of its quartz crystal material a Photo-sensitive resistor: changing its resistance when exposed to light• Physical-property-type transducers : based on the change in physical properties of its sensing element material to realize signal conversion ▪ Pressure accelerometer : based on the piezoelectric effect of its quartz crystal material ▪ Photo-sensitive resistor : changing its resistance when exposed to light 4.2 Classifications of transducers