With the rapid advancement of science and technology, high-tech applications have become widespread across industries. High-tech magnetostrictive level sensors are now employed for liquid level measurement in various storage tanks. This type of level instrument features high precision, strong environmental adaptability, and convenient installation. Consequently, it is widely used in the petroleum, chemical, and other industries for level measurement, gradually replacing traditional sensors and becoming a premium solution in this field.

The advantages of using magnetostrictive level gauges for measuring liquid levels in tanks are as follows:

1)High reliability : Magnetostrictive level gauges employ the waveguide principle, featuring no mechanical moving parts, thus eliminating friction and wear. The entire transducer is enclosed in a stainless steel tube, ensuring non-contact with the measured medium. This design guarantees reliable sensor operation and a long service life.

2)High precision : The gauge operates using waveguide pulses, determining displacement by measuring the time between the start and end pulses. This achieves a resolution better than 0.01% FS (Full Scale) , a level of accuracy difficult to match with other sensor types.

3)Safety : With intrinsically safe explosion-proof capabilities, magnetostrictive level gauges are ideal for measuring chemical raw materials and flammable liquids. Measurements can be taken without opening the tank, eliminating safety risks associated with manual methods.

4)Easy installation and maintenance : Typically installed through existing tank-top ports, these gauges are well-suited for underground or already operational tanks. Installation does not disrupt normal production processes.

5)Automation compatibility : The secondary instrument uses standard output signals (e.g., 4-20mA), facilitating signal processing by microcomputers and enabling networked operations to enhance system automation.

The magnetostrictive level gauge consists of three main components: a measuring rod, an electronic circuit unit, and a float. During measurement, the circuit unit generates an electric current pulse, which travels downward along the magnetostrictive waveguide wire, creating a circular magnetic field. The float, equipped with a permanent magnet inside, is positioned outside the measuring rod and moves up and down with liquid level changes. When the current-induced magnetic field interacts with the float’s magnetic field, a “twist pulse” (also termed a “return pulse”) is generated at the point of interaction. By measuring the time difference between the initial current pulse and the received twist pulse, the system calculates the float’s exact position, thereby determining the liquid level.

1.Pre-Installation Notes

a) Environmental Conditions : Carefully read all installation instructions to ensure the installation environment does not exceed the sensor’s allowable limits for temperature, shock, vibration, or pressure.

b) Mechanical Protection : No bending of the measuring rod is allowed. Avoid applying significant impact to the transmitter’s electronic component terminal or endmost part.

c) Chemical Resistance : Sensors must not be used in environments involving chemical reactions, flammable/explosive materials, corrosive substances, vapors, or liquids that could damage the sensor.

d) Water Protection : The electronic components are splash-proof but not submersible .Ensure no liquid reaches above the hexagonal base.

e) Post-Installation Handling : After installation, apply protective measures to the measuring rod to prevent damage.

2.Sensor Installation Instructions

a)Sensor Bracket Fixation : Secure the sensor using a sensor bracket and fasten the bracket to the sensor’s threaded section with a locking nut.

b)Magnet Ring Installation : Fix the split magnet ring to the magnet ring bracket using two anti-loosening washers (#6) and two dedicated screws (M3*12). When installing the magnet ring on the measuring rod: Ensure the screw heads face the hexagonal base side. The magnet ring should be as concentric as possible with the measuring rod and without physical contact. Slight eccentricity of the magnet ring does not affect sensor performance .

c)Fixing Strips : Wrap the fixing strip tightly around the endmost section of the measuring rod and secure it with two M3*8 screws and two M3 nuts.Note : MS-1 Installation Kit : Includes one fixing strip , which must be mounted within 50mm of the measuring rod’s end. MS-2 Installation Kit : Includes three fixing strips : One strip is installed within ~25mm of the end.

The remaining two strips are evenly distributed along the measuring rod.

d)Final Fixation : After initial assembly, secure the entire pre-assembled sensor unit to the installation location using custom-made screws as required.

Key Technical Notes : Anti-loosening Washers (#6) : Ensure proper torque to prevent vibration-induced loosening.Concentricity : Critical for sensor accuracy; verify alignment during installation. Hexagonal Base : Acts as a reference point for component orientation.

Wiring Method:

1.The level gauge wiring compartment has two terminals labeled “24V” and “Signal”. Connect “24V” to POOL+ and “Signal” to POOL- .

2.The cable must have a shielded layer, and the shielding wire should be connected to the grounding bolt .

3.The load resistance must not exceed 300Ω .

Precautions:

1.Each sensor must be powered by a dedicated power supply that meets product specifications.

2.Shielded cables for sensors should be kept away from high-power power supplies, RF signal sources, and other noisy transmission lines .

3.Ensure the shielding mesh of the cable is intact (no breaks) and connected to the ground terminal of the downstream equipment.

The sensor requires proper calibration prior to use. A multimeter with a voltage resolution of 1mVDC or current resolution of 1µADC is needed for zero-point and full-scale adjustments (speed output does not require adjustment). The calibration procedure for zero-point and full-scale (standard wiring) is as follows:

• Mount the magnetic ring onto the measuring rod and move it from the topmost position toward the end.

• Loosen the sealing screws on the side of the electronic component using a screwdriver.

• Connect the multimeter to the corresponding output lines for adjustment.

Zero-point Adjustment

Note: The nominal range is factory-set, calculated from 50.8mm (or a customer-specified position) above the hex base. The zero-point adjustment range is 20% of the measurement range. In reverse mode, this range becomes the full-scale adjustment range (use the full-scale potentiometer for adjustment). The zero-point potentiometer is factory-calibrated to its optimal position. When the magnetic ring is positioned to produce a zero output (electrical zero), align it with the mechanical zero during installation. If the mechanical zero is non-adjustable, follow these steps:

A. Place the magnetic ring at the desired zero-point position.

B. Carefully insert the screwdriver into the adjustment hole on the left side of the electronic component (ensure the screwdriver is fully seated in the potentiometer slot before rotating).

C. Adjust the zero-point potentiometer (clockwise rotation increases the output signal; counter-clockwise decreases it) until the multimeter reads 0.000 ± 0.001 VDC , -5.000 ± 0.001 VDC , -10.000 ± 0.001 VDC , or 4.000 ± 0.001 mA DC .

Full-scale Adjustment

Note: The full-scale potentiometer has a 20% F.S. adjustment range. In reverse mode, this becomes the zero-point adjustment range (use the zero-point potentiometer instead).

A. Position the magnetic ring at the desired full-scale point.

B. Insert the screwdriver into the full-scale potentiometer slot.

C. Adjust the full-scale potentiometer (clockwise increases output; counter-clockwise decreases it) until the multimeter reads 5.000 ± 0.001 VDC , 10.000 ± 0.001 VDC , or 20.000 ± 0.001 mA DC .

Repeat these steps until both zero-point and full-scale values fall within the specified range.

• Retighten the zero-point and full-scale sealing screws. Calibration is complete, and the sensor is ready for use.

• Warning: Explosion-proof level sensors must not be calibrated on-site.