Two kinds of pressure flange level transmitter of the medium to be measured through into the high and low pressure chamber, the role of the delta components (i.e. responsive element) on both sides of the isolation diaphragm, isolation and the element by filling liquid is transferred to a measurement on both sides of the membrane. The flange type liquid level transmitter is a capacitor which is composed of a measuring diaphragm and an electrode on both sides of the insulating sheet. When both sides of the pressure is not consistent, resulting in the measurement of the diaphragm displacement, the displacement and pressure difference is proportional to the two sides of the capacitance range, through the oscillation and demodulation process, and the pressure is converted into a signal. The working principle of the pressure transmitter and the absolute pressure transmitter is the same as that of the differential pressure transmitter.

The A/D converter converts the current of the demodulator into a digital signal, and the value is used by the microprocessor to determine the input pressure value.

Microprocessor control transmitter. In addition, it makes sensor linearization. Reset measurement range. Engineering unit conversion, damping, prescribing, fine-tuning operations, sensors, and diagnostic and digital communication.

This microprocessor has 16 byte program RAM, and there are 16 three bit counters, one of which performs /D A conversion.

The D/A converter converts the microprocessor to the corrected digital signal to fine tune the data, and the data can be modified by the transmitter software. Data is stored in the EEPROM, even when the power is off.

Digital communication lines for the transmitter to provide the interface of a with external devices (such as 205 intelligent communicator or with HART protocol control system). The circuit detects the digital signal superimposed on the 4-20mA signal, and transmits the required information through the loop. Type of communication for frequency shift keying FSK technology and based on BeII202 standard.