These operations reduce the error of the level transmitter

These operations reduce the error of the level transmitter

The working principle of the liquid level transmitter is that the process pressure is transmitted to the center measuring diaphragm of the delta chamber through the isolating diaphragm on both sides and the tank liquid; the central diaphragm is a tensioned elastic element for acting on it. The pressure difference between the two sides produces a corresponding deformation displacement, the displacement is proportional to the differential pressure, the displacement is about 0.1mm, and the displacement is converted into the differential capacitance formed on the capacitor plate, and the differential capacitance signal is converted into the second line by the electronic circuit. 4-20mA DC output signal. The liquid level transmitter is suitable for liquid level measurement of various media in petrochemical, metallurgy, electric power, pharmaceutical, water supply and drainage, environmental protection and other systems and industries. The compact structure, simple adjustment and flexible installation make it easy for users to use. Standard signal output methods such as 4 to 20 mA, 0 to 5 v, and 0 to 10 mA are optional by the user as needed.

The method for reducing the error of the liquid level transmitter is as follows:

1) The pressure guiding tube should be as short as possible;

2) When measuring liquid or steam, the pressure guiding tube should be connected upwards to the process pipeline, and the liquid level transmitter should have a slope of not less than 1/12;

3) For gas measurement, the pressure guiding tube should be connected down to the process pipeline, and the slope of the liquid level transmitter should be no less than 1/12;

4) The layout of the liquid pressure guiding pipeline should avoid the occurrence of high points, and the layout of the gas pressure guiding tube should avoid the occurrence of low points;

5) The two pressure guiding tubes should maintain the same temperature;

6) In order to avoid the influence of friction, the diameter of the pressure guiding tube should be large enough;

7) There should be no gas in the pressure-filled tube filled with liquid;

8) When using spacer liquid, the liquid level of the pressure guiding tubes on both sides should be the same.

Maintenance method of the liquid level transmitter:

1. When the liquid level transmitter freezes in winter, the liquid level transmitter installed outside must adopt anti-freezing measures to prevent the liquid in the pressure inlet from expanding due to the ice volume, leading to damage to the sensor.

2. When wiring, pass the cable through the waterproof connector (accessory) or the winding tube and tighten the sealing nut to prevent rainwater from leaking into the transmitter housing through the cable.

3. When measuring the pressure of the gas, the pressure port should be opened at the top of the process pipe, and the liquid level transmitter should also be installed in the upper part of the process pipe to allow the deposited liquid to be quickly injected into the process pipe.

4. When measuring the steam or other high-temperature medium of the liquid level transmitter, it is necessary to add a condenser such as a buffer tube (coil), and the operating temperature of the liquid level transmitter should not exceed the limit.

5, the liquid level transmitter should pay attention to the sensor's pressure guiding tube should be installed in places with small temperature fluctuations.

6. When measuring the liquid pressure, the installation position of the liquid level transmitter should avoid the impact of the liquid (that is, the water hammer phenomenon), so as to avoid the sensor over-voltage damage.

7. When measuring the liquid pressure, the liquid level transmitter should be opened on the side of the process pipeline to avoid sedimentation.