The MDM uses piezoresistive differential pressure sensor as a sensing element. Silicon oil is filled between a die and two diaphragms. When the measured differential pressure is applied on the two diaphragm, the pressure is transferred onto the die through the silicon oil. The die sensor connects with an amplifier circuit through wires, using semi-conductor's piezoresistive effect, transforming differential pressure signal into electric signal. The whole product is used for differential pressure measurements of petroleum, chemical industry, power station and hydrology. This transmitter is suited for measuring up to 3.5MPa.Pa.