Magnetic flip column level gauges are widely used for level measurement in industries such as chemical, energy, and food due to their high sealing, corrosion resistance, and intuitive reading characteristics. Its nominal accuracy reaches±10mmHowever, in actual use, it is necessary to maintain it continuously through standardized operation and regular maintenance. This article analyzes the key points to ensure measurement accuracy from three dimensions: installation, use, and maintenance.

1、 Installation phase: Avoid basic errors

1. Verticality and spatial calibration

The main pipe of the liquid level gauge must be installed strictly vertically, with a maximum allowable deviation angle≤3°If installed at an angle, the magnetic coupling efficiency between the float and the magnetic flip column will decrease, resulting in indication lag or flip column jamming. For example, a storage tank level gauge in a chemical enterprise was installed at an angle5°The liquid level display is lower than the actual value8%Deviation. During installation, a level should be used for calibration and within the measurement range of>4mAdd intermediate support points to prevent deformation of the main pipe.

2. Magnetic interference isolation

Surrounding the liquid level gauge200mmIt is prohibited to place magnetic materials such as excitation iron parts and motors within the range, otherwise the external magnetic field will interfere with the signal transmission of the magnetic steel inside the float. Due to the proximity of the solenoid valve, the level gauge of a certain steel plant's blast furnace had a chaotic indication of column flipping. After rectification, the accuracy was restored to±8mm.

2、 Usage stage: Standardized operation to prevent deviation

1. Media compatibility verification

The liquid level gauge needs to be based on the density of the medium（0.5～2.0g/cm³）Viscosity（≤0.4Pa·s）Choose the model based on temperature. For viscosity>0.4Pa·sFor media such as heavy oil or easily crystallizable media such as ammonium sulfate solution, a heating jacket type liquid level gauge should be selected to prevent the float from getting stuck. Due to the lack of a heating jacket installed in a certain refinery, the level gauge of the heavy oil storage tank measured incorrectly in winter±30mm.

2. Zero calibration before commissioning

After the first use or maintenance, the zero liquid level needs to be adjusted by adjusting the screw: first open the upper flange gas phase valve, and then slowly open the lower flange liquid phase valve to allow the medium to slowly flow into the main pipe, and observe whether the flipping of the column is synchronized with the actual liquid level. The liquid level gauge of a certain pharmaceutical company's reaction kettle had an initial error of±15mmAfter recalibration, the accuracy was restored to±5mm.

3、 Maintenance phase: Preventive maintenance strategy

1. Regular cleaning and sealing inspection

Check the sealing of the main pipe and process connection flange every month to prevent the float from sinking due to medium leakage. Wipe the flipping column panel with a soft cloth every quarter to remove dust or condensation and avoid sticking the flipping column. The liquid level gauge of a syrup storage tank in a certain food factory experienced a delay in indication due to uncleaned columns, but the error was eliminated after cleaning.

2. Float status monitoring

Check the magnetic strength of the magnetic steel inside the float every year. If the magnetic attenuation exceeds30%The float needs to be replaced. The liquid level gauge of a chlor alkali storage tank in a certain chemical plant failed to flip synchronously due to the weakened magnetic properties of the float. After replacing the float, the accuracy met the standard.

3. Remote transmission module calibration

If optional4-20mARemote transmitters require calibration of output values using a standard signal source every six months. The control room of a certain sewage treatment plant once displayed a lower liquid level than the actual value due to transmitter zero drift0.5mAfter calibration, it returns to normal.

Conclusion: Precision assurance requires full process control

Magnetic flip column level gauge±10mmAccuracy depends on the synergistic effect of installation verticality, medium adaptability, zero position calibration, and regular maintenance. By establishing standardized operating procedures（SOP）And preventive maintenance plan（PM）Can extend the service life of the equipment to8Over years, while controlling measurement errors within the design range, providing reliable guarantees for industrial process safety and efficiency.