When pressure is app lied to diaphragm 1, electric charges
(piezoelectric charges) are developed on the surfaces of quartz
wafers 2, which contact electrode 3 and plates 4. The am ount of
the charges is proportional to the pressure app lied to diaphragm
1. Metal plates 4 serve to transm it pressure from d ia phragm
1 to crystal wafers 2. Electrode 3 serves to conduct the
charges to the measuring instrument.