1) Characteristics of magneto electric induction sensors

Magnetic electric induction sensor, abbreviated asInductive sensorAlso known as electric sensors. It converts the changes in the measured physical quantity into induced electromotive force. It is an electromechanical energy conversion sensor that does not require an external power supply, has a simple circuit, stable performance, low output impedance, and a certain frequency response range (generally 10-1000Hz). It is suitable for measuring vibration, speed, torque, and other parameters. Inertial sensors do not require a stationary base as a reference, and are directly installed on the vibrating body for measurement. Therefore, they have been widely used in ground vibration measurement and airborne vibration monitoring systems. But thissensorThe size and weight are both relatively large.

2) Magneto electric induction typesensorWorking principle, classification and application of the coil: According to the law of electromagnetic induction, an N-turn coil moves in a magnetic field to cut magnetic field lines, generating an induced electromotive force e inside the coil. The size of e is related to the rate of change of the magnetic flux Φ passing through the coil. According to different working principles, magneto electric induction sensors can be divided into constant flux and variable flux types, namely, moving coil sensors and magneto resistive sensors. Constant flux magneto electric induction sensors can be divided into moving coil type and moving iron type according to the different moving parts. The center coil of a moving coil magneto electric sensor is a moving component, and its basic form is velocitysensorIt can directly measure linear velocity or angular velocity. If an integration circuit or differentiation circuit is connected to its measurement circuit, it can also be used to measure displacement or acceleration; The moving component of the moving iron type magneto electric induction sensor is the iron core, which can be used for measuring various vibrations and accelerations.

Variable magnetic flux typeMagneto electric induction sensorIn the middle, both the coil and the magnet are stationary, and rotating objects cause changes in magnetic resistance and flux, which are commonly used to measure the angular velocity of rotating objects. As shown in the animation, coil 3 and magnet 5 are stationary. Measure gear 1 (made of magnetic material), and for each tooth it rotates, the magnetic resistance of the sensor's magnetic circuit changes once. The frequency of the induced electromotive force generated by coil 3 is equal to the product of the number of teeth on gear 1 and its rotational speed. Variable magnetic flux typesensorThe requirements for environmental conditions are not high, and it can work at temperatures ranging from -150 to+90 ℃ without affecting measurement accuracy. It can also work under conditions such as oil, water mist, and dust. But its lower limit of operating frequency is relatively high, about 50Hz, and the upper limit can reach 100Hz.