Meaning
Electromechanical position measurement relies on a differential transformer that generates an electrical AC voltage proportional to the physical movement of a magnetic core through its coil winding. An lvdt displacement sensor measures linear travel in heavy industrial machinery, hydraulic actuators, and valve position feedback loops. Operating performance covers millimeter scales up to several hundred millimeters while stopping at nanometer resolutions where optical encoders dominate.
Core Architecture
Construction involves a central primary coil surrounded by two secondary coils wound symmetrically on a cylindrical form. Magnetic coupling changes as a ferromagnetic core travels axially inside the bore, inducing varying voltages in the secondary windings. Signal conditioning electronics convert these differential outputs into a direct current voltage level or digital stream proportional to position.
Signal Precision
Output linearity depends entirely on primary excitation frequency stability and phase angle demodulation circuitry. Thermal drift inside the copper windings alters resistance values over extended temperature ranges, demanding internal compensation networks to maintain calibration accuracy. Purchasing engineers evaluate zero balance offset and total electrical stroke before committing capital to harsh vibration environments.
Operational Boundaries
Core friction remains nonexistent because mechanical contact never occurs between the moving rod and the stationary coil housing. Infinite mechanical resolution stems from this frictionless coupling, allowing continuous tracking without wear over millions of actuation cycles. Saturation limits in the magnetic core restrict application scope when operating near high magnetic fields unless external shielding enclosures are specified.
