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Magnetic flap level gauges are suitable for measuring the liquid level of various media in water towers, pools, tanks, sumps, and industrial tanks in both industrial and civil buildings. They are widely used in fields such as level measurement, chemicals, metallurgy, power generation, paper manufacturing, food processing, and industrial wastewater treatment. The product consists of a magnetic floating ball, a detection tube, and a signal transmitter. As the magnetic floating ball rises and falls with the liquid level, the transmitter converts the resistance signal within the sensing tube into a standard 4–20 mA.DC current signal, thereby enabling the measurement and control of the liquid level. It consists of a level sensor and an intelligent HART board (current converter). The float moves in sync with the liquid level, which controls the engagement and disengagement of the reed switch; this causes the resistance inside the sensor to change linearly. The converter then converts this change in resistance into a standard 4–20 mA current signal, which is combined with a HART digital signal for output. In the operation of a magnetic flap level gauge, the magnetic float can experience demagnetization, and this demagnetization leads to the failure of the gauge. High-temperature magnetic flap level gauges (especially those designed for high temperature and pressure) are typically used in environments where the temperature exceeds 180 degrees Celsius, and their detachable design poses certain risks during installation. The solutions to the demagnetization problem in magnetic flap level gauges can be categorized into the following aspects: 1. From a design perspective, it is necessary to select appropriate hard magnetic materials. For example, magnetic materials with a Curie temperature that is at least 20% higher than the operating temperature should be chosen, to ensure that the residual magnetism remains above the critical value after five years. 2. From a production perspective, the following points need to be taken into account when processing magnetic floats: 3. Cooling measures must be employed during welding (TIG welding) to prevent the temperature of the magnetic material in the float from exceeding its Curie temperature. 4. The magnetic float is filled with an inert gas (such as argon) ； From a usage perspective, users should do the following: 1. Select the appropriate model when placing an order, ensuring that the operating temperature does not exceed the nominal temperature of the magnetic flap level gauge ； 2. During use, it is necessary to constantly monitor the performance of the level gauge (to ensure it is functioning properly), as well as record the actual temperature of the medium. I have seen cases where the actual operating temperature is often higher than the temperature indicated in the specifications; those who prepared the design specifications may have overlooked certain factors. The magnetic flap level gauge is a commonly used instrument for measuring liquid levels. It features a simple structure, ease of use, stable performance, long service life, and convenience in installation and maintenance. It is widely employed in various fields such as petroleum processing, food processing, chemicals, water treatment, pharmaceuticals, power generation, papermaking, metallurgy, shipbuilding, and boilers for the measurement, control, and monitoring of liquid levels. However, during the testing process, due to the influence of interfering factors, magnetic float level gauges can experience the following fault issues, which affect the accuracy of the measurement results. Therefore, let’s take a look at these fault problems of magnetic float level gauges: 1. After the level gauge has been in use for some time, the float may have difficulty floating and its movement may be sluggish. This is fundamentally caused by iron filings or other contaminants sticking to the magnetic float. The medium can be emptied first, followed by the removal of the float, thereby eliminating any iron filings or other contaminants attached to it. 2. During on-site calibration, it is occasionally found that the float does not move up and down sufficiently smoothly. This is mostly caused by improper installation of the level gauge; in such cases, it is necessary to check whether the centers of the upper and lower flanges are on the same line and whether they are perpendicular to the horizontal plane. Generally speaking, the angle with the level surface should be no less than 87 degrees; if it is too large, it may affect the smooth movement of the float. 3. When selecting an intrinsically safe level gauge, special attention should be paid to whether the impedance of the level gauge matches that of the safety barrier. 4. The maglev ball level gauge was calibrated properly, but after it was put into use, the float exhibited a phenomenon of \"sticking\" in one position for a certain period of time. This is mainly caused by the level gauge being too close to the steel plate when it passes through the steel platform assembly. Therefore, when passing through the steel platform installation, special attention must be paid to the distance between the wall of the magnetic flap level gauge’s connecting pipe and the cutting edge of the platform. 5. During the operation of the level gauge, if there are frequent disturbances in the output signal or interference pulses, it is necessary to check whether the shielding layer of the signal cable is properly grounded, and whether the resistance of the working connection meets the required standards. 6. When putting the level gauge into use on-site, special attention should be paid to opening the upper gate valve first, and then the lower gate valve. This is because the bottom of the level gauge’s connecting tube is equipped with a thrust spring for the maintenance float; otherwise, the effect of high differential pressure could break the float, rendering the level gauge unusable. 7. If the sealed glass tubes used for on-site indication break due to transportation or other reasons, they can be replaced with domestically produced glass tubes. But it’s best to evacuate it. Also, pay attention to whether the glass tube is vertical, so as not to affect the indicator reading. 8. When using a magnetic float level gauge, it is essential to be careful: never use a strong magnet to pull the float up and down outside the connecting tube for inspection, as this will cause the magnetic float to become magnetized and its polarity to change. This can result in a decrease in the float’s magnetic strength, making it difficult for the gauge to function properly. Common faults of magnetic flap level gauges and their solutions: The float does not move: ① The density of the liquid is lower than that of the float; ② The float is leaking water; ③ Foreign objects are blocking the float. Solutions: ① Recheck the density of the float; ② Contact the company to have a new float installed; ③ Remove any foreign objects. The float moves, but no signal is generated: ① The position of the float is incorrect; ② The reed switch is damaged. Solutions: ① Adjust the position of the float; ② Replace the reed switch. Abnormal signal output due to magnetic interference in the vicinity. Solution: Eliminate the magnetic field; the signal remains unchanged, it cannot be restored, the float ball cannot return to its original position, as there is a foreign object stuck there. Solution: Remove the foreign object; this will result in two signal outputs, and the position of the ring buckle will change. Solution: Adjust the position of the loop. For more information, please visit the company’s official website at http://www.yb1518.com/. Please retain this link when reproducing the content! http://www.yb1518.com/uploadfiles/image/2010-11//201011191011384084.jpg