Theory, Characteristics and Application of LVDT Displacement Sensor
Theory, Characteristics and Application of LVDT Displacement Sensor
LVDT displacement sensor is the abbreviation of linear differential variable pressure displacement sensor. The working principle of LVDT displacement sensor is that three groups of coils, one group of primary coils and two groups of secondary coils are hung on a hollow skeleton. When the primary coil is energized, a magnetic field will be formed in the spacetime skeleton. When a magnetic core is inserted into the hollow skeleton, two secondary coils will form a weak AC voltage due to the principle of cutting magnetic induction lines. When the iron core moves to the position of a secondary coil, the output voltage of the secondary coil is larger than that of the other coil. According to this rule, the voltage values output by the two secondary coils are amplified, and then the two voltage values are subtracted to obtain a difference value, which is in direct proportion to the displacement of the iron core in the hollow skeleton. This difference value can be processed into analog signals such as -5V, 0-10V, 4-20mA or Modbus SSI.
The advantages of LVDT mainly include: non-contact principle, good wear resistance, high resolution, good repeatability, no sliding contact and long service life; Fast response speed; High linearity; Good repeatability; Wide range coverage; Low fault/low power consumption/diversity of input and output; Good dynamic characteristics, can be used for high-speed online detection, automatic measurement and automatic control; Can be used in harsh environments such as humidity and dust; Can work under special conditions, such as high pressure resistance, high temperature resistance, radiation resistance, full-tight soil seal working underwater; It can withstand impact up to 150g/11ms, vibration frequency 2KHZ acceleration 20 g; Small size, low price and high performance-price ratio.
It is suitable for high-precision and high-repeatability measurement in quality control and measurement applications.
Product features:
1. Small size, high precision and long mechanical life.
2. It can be installed inside the workpiece for more convenient measurement.
3. the length of the head can be increased, and the contact range with the surface of the workpiece is wider.
4. The error caused by removing the lateral force friction is smaller.
Industry application: It is mainly used for the rapid detection of cycling parts, axle diameter, internal and external circle runout, end runout and other products.
It is widely used in automobile, aerospace, military industry, machinery, textile, railway, metallurgy, scientific research institutes and other industries of national economy.