LVDT principle are constructed with a primary and two secondary coils, arranged symmetrically to the primary winding. An electronic oscillator supplies the primary coil with an alternating current of constant frequency (between 1~10 kHz) with a excitation voltage (AC) of a few volts.

As a measurement object (a rod shaped magnetic core) is moved within the differential transformer.

Depending on the core position alternating voltages are induced into the two secondary windings. If the core is located in its "zero position", the coupling of the primary to both secondary coils is equal giving zero output.

Movement of the core within the magnetic field of the coil causes a higher voltage in one secondary coil and a lower voltage in the second coil. The difference between the two secondary voltages is proportional to the core displacement. Due to the differential design of the sensor, the LVDT series has very stable output signal for good performance.

LVDT – Full Bridge

LVDT – Half Bridge

Numerous application possibilities

 Quality control (dimensional accuracy)

 Research and development

 Positioning tasks

 Building monitoring

For the measurement of:

Thickness, planarity, deflection, depth