NEWS CENTER
Working Principle and Application of Magnetostrictive Sensors
Time：
2025-05-12
1. Introduction
Magnetostrictive sensors are precision devices used to measure position, displacement, or level in a wide range of industrial and automation applications. They offer high accuracy, non-contact measurement, and excellent durability, making them ideal for use in harsh environments such as manufacturing plants, hydraulic systems, and oil tanks.
2. Working Principle
The operation of a magnetostrictive sensor is based on the magnetostrictive effect, a property of certain ferromagnetic materials that causes them to change shape or dimensions when exposed to a magnetic field. Magnetostrictive sensors also rely on the generation and detection of ultrasonic torsional waves in a waveguide.
The sensor typically consists of three main components:
A waveguide (typically a nickel alloy rod)
A movable permanent magnet (position magnet)
Electronics that generate and detect signals
Step-by-Step Process:
Excitation Pulse: An electrical pulse is sent through the waveguide, generating a circular magnetic field around the waveguide due to the current.
Interaction with Position Magnet: The position magnet, which moves along with the object being measured, produces a static longitudinal magnetic field. Where the two magnetic fields interact, a torsional strain (mechanical wave) is generated in the waveguide due to the magnetostrictive effect.
Propagation of Torsional Wave: This mechanical wave travels along the waveguide toward the receiving electronics at a known speed.
Signal Detection and Time Measurement: A pickup coil or piezoelectric sensor detects the returning wave. The system measures the time difference between the excitation pulse and the received torsional wave.
Position Calculation: Since the speed of the torsional wave in the waveguide is constant and known, the time delay is used to accurately calculate the position of the magnet.
3. Advantages
Non-contact measurement (no wear and tear)
High resolution and repeatability
Immunity to vibration, temperature, and contamination
Fast response time
4. Typical Applications
Hydraulic cylinder position sensing
Injection molding machines
Material handling systems
Tank level monitoring
Robotic positioning systems
5. Installation and Usage Tips
Ensure the waveguide is properly aligned and securely fixed.
The position magnet should move linearly and be within the specified sensing distance from the waveguide.
Avoid placing the sensor near strong external magnetic fields to prevent interference.
Use compatible signal conditioners or controllers to process the sensor output, which may be analog (e.g., 0–10V, 4–20mA) or digital (e.g., SSI, PWM, CANopen).
6. Conclusion
Magnetostrictive sensors provide reliable and highly accurate position feedback in a variety of challenging environments. Their non-contact nature extends sensor life and ensures consistent performance, making them an essential component in modern automation and control systems.
Prev： Internal Structure and Working Principle of Double-Chamber Balancing Vessel
Next： Understanding the Working Principle and Applications of Float Level Meters
Hot news
Celebrating both festivals, families and country unite in unity. In this season of refreshing autumn air and fragrant osmanthus blossoms, we welcome the beautiful encounter of Mid-Autumn Festival and National Day. VACORDA extends its sincerest holiday greetings to all its hardworking employees, our trusted and supportive customers, and the people of China!
Address：Guanghua Rd, Qingyang Dist, Chengdu, Sichuan Province, China
E-mail：sales@vacorda.com
Copyright © 2024 Sichuan VACORDA Instruments Manufacturing Co., Ltd.
