NewTek Sensor Solutions offers a free downloadable learning module on Free-Core vs. Spring Loaded LVDT Position Sensors that focuses on the differences between the technologies and ideal applications.
While both sensors convert the linear position or motion of a measured object into an electrical output that is displayed or input into a PLC, free core and spring-loaded LVDTs have different constructions. While free-core LVDT sensors have a floating core unit not attached to any coils, a spring-loaded configuration has a core connected to a spring-loaded probe shaft with a ball tip.
Spring-loaded LVDTs also are available in air-actuated versions that operate with low pressure air that extends the sensor’s shaft. Probe contact force is regulated by air pressure so that when it is removed, an internal spring retracts the sensing probe to avoid any damage when gaging parts such as in an assembly line.
While the free-core LVDTS offer high reliability with the absence of friction during operation as well as robustness for long life, spring-loaded LVDTs, also known as gaging probes, remain in constant contact with the measured object for highly repeatable and accurate measurement. They are popularly used in dimensional gaging of components as part of manufacturing quality assurance.
The learning module discusses real-world applications for both technologies including the use of spring-loaded gage heads for measuring surface parameters on a manufacturing line and free-core LVDTs fo
