BASIC PRINCIPLE AND ORIGIN OF LVDT

The letters LVDT are an acronym for Linear Variable Differential Transformer. Ever since being introduced as a lab measurement tool for military use during WWII, the linear variable differential transformer, or LVDT, has expanded its use into industrial, commercial, aerospace, subsea and process control applications. A highly reliable displacement feedback device, the LVDT linear position sensor is capable of measuring movements as small as a few millionths of an inch up to ± 20 in. (<±0.5 m). 

As showed in the picture below, LVDT construction involves three sets of winding: One primary and two secondaries. A core composed of magnetic material based on nickel alloy is usually attached to a moving object that needs to be sensed. The primary coil is driven from an DC signal,  hrough magnetic induction, secondary coils pick up the signal as the core moves. The LVDT generates an electrical output signal that is the differential DC voltage between the two secondary windings, which varies with the axial position of the core within the LVDT coil.

APPLICATION

LVDT is widely applied in Aerospace, Machinery, Construction, Textile, Railway way,Coal mine, Metallurgy, Plastic, Chemical industry and Academic research,which is used to measure the distance, vibration,thickness, expansion and so on.
We also provide digital output.The integrated circuit is hermetically sealed in SUS 304 stainless steel sleeve, which can ensure the transducers works accurately and reliably in hostile environment such as damp and dust, corrosion, etc.  

SPECIFICATION

1. High pressure resistance,withstand 35MPa.
2. 4-wire switching signal, 6-wire AC signal.
3. 2-wire: 4-20mA output; 3-wire:voltage output..
4. AC output,wide range motivated voltage (AC output)
5. Power supply 9 - 28V DC, power consumption <2W.
6. Measuring range(2.5 - 35mm).
7. Linearity<1%.
8. Protection grade can reach IP67.
9 Highly integrated,small size.

REAL PICTURES OF SOWAY LVDT