Designing method for sensing body mechanism of differential pressure transmitter using silicon diaphragm type pressure sensor

This paper describes a designing method of the three-diaphragm type sensing body of differential pressure transmitter for protecting silicon diaphragm type pressure sensor from an over-pressure. This method includes how to decide each stiffness of three metal diaphragms and liquid quantity filled in the sensing body. This method is applied to differential pressure transmitters with measuring ranges from 0-0.6 kPa to 0-400 kPa. As a result, transmitters with significant stabilities are obtained: a zero and span influence of a static pressure and an over-pressure are less than 0.2% at a line pressure of 15 MPa.<>