The working principle of the UQZ-17LX type liquid level transmitter is when the two kinds of pressure of the medium are tested into high and low pressure chambers, which function on the separate diaphragm of the delta element (i. e. the sensitive element), through the spacer and the filler liquid in the component to the measuring diaphragm.
The UQZ-17LX type (floating ball) liquid level transmitter is made up of the measuring diaphragm and the electrodes on both sides of the insulating sheet to constitute a capacitor. When the two sides of the pressure inconsistent, resulting in the measurement of the diaphragm displacement, the displacement and pressure difference is proportional, so the two sides of the electrical capacity of unequal, through the oscillation and demodulation link, converted to the pressure proportional to the signal. The pressure transmitter and the absolute pressure transmitter work principle and the differential pressure transmitter is identical, the difference is that the low-pressure chamber pressure is atmospheric or vacuum.
A/D converter converts the current of the demodulator into a digital signal whose value is used by the microprocessor to determine the input pressure value. The microprocessor controls the work of the transmitter. In addition, it is linearized for sensors. Resets the measurement range. Engineering unit conversion, damping, radical, sensor fine-tuning and other operations, as well as diagnostics and digital communication.
This microprocessor has a 16-byte program RAM and has three 16-bit counters, one of which performs A/D conversion.
D/A converter converts the microprocessor to the corrected digital signal, which can be modified by the transmitter software. Data is stored in the EEPROM, even if the power outage is preserved intact.
A digital communication line provides a connection interface to a transmitter with an external device such as a 205-type intelligent Communicator or a control system using the Hart protocol. This line detects the digital signal superimposed on the 4-20mA signal and transmits the required information through the loop. The type of communication is the frequency shift keying FSK technology and according to the BEII202 standard.