1、 Selection of liquid level transmitter
1. The consideration is the characteristics of the medium, such as the content of impurities, whether it is easy to scale, and so on, which is the influence on the measurement of liquid level instrument.
2. The working conditions, such as pressure, temperature and liquid level range, determine the optional range of liquid level gauge;
3. Consider the installation method, such as the opening position, diameter, standard and material of the liquid level gauge on the process equipment; consider the price for others; primary selection of instrument manufacturer; repair and maintenance; after-sales service, etc.
2、 Selection of supporting instruments
1. Digital display: it can directly show the depth of the detected liquid, which is more in line with the viewing habits. Arbitrary setting of liquid level point: the liquid level parameter value required on site can be set arbitrarily on the display and control panel, which is easier to use. Relay switch output: normally open / normally closed, easy to meet various automatic control requirements.
2. Definition of output direction: it can make each liquid level point output according to the rising or falling output, which conforms to the conventional custom.
3. Computer communication: it can form a computer centralized monitoring and management system.
4. Return differential protection: avoid misoperation caused by liquid level fluctuation and protect the safety of control system.
5. Fault self inspection: when the signal of liquid depth transmitter exceeds the range or the connecting line is open or short circuited, the fault code will be displayed to facilitate maintenance.
6. Display translation correction: when the installation position of the liquid depth transmitter is lower than or higher than the bottom surface of the detected container, it can be corrected to make the liquid depth display value and the actual liquid depth value the same, more intuitive.
7. Liquid specific gravity correction: when detecting the depth of liquid with different specific gravity, it can be corrected to make the displayed value of liquid depth consistent with the actual value of liquid depth, which is more intuitive. Electronic parameter lock: to avoid the wrong setting and operation of non professional technical personnel.