Linear Variable Differential Transducer
LVDT (Linear Variable Differential Transformer), is an absolute position/displacement transducer that converts a position or linear displacement from a mechanical reference (zero, or null position) into a proportional electrical signal containing phase (for direction) and amplitude (for distance) information. The LVDT operation does not require an electrical contact between the moving part (probe or core assembly) and the coil assembly, but instead relies on electromagnetic coupling; this and the fact that LVDTs can operate without any built-in electronic circuitry are the primary reasons why they have been widely used in applications where long life and high reliability under very severe environments are a required, such as in Military/Aerospace, process controls, automation, robotics, nuclear, chemical plants, hydraulics, power turbines, and many others.
LVDT’s come in two different varieties, either DC or AC output. DC versions in general have integral electronics or there is limited need for complex signal conditioning, or AC variants which will require signal conditioning. There are lots of object application based uses for a LVDT device, as they are not electromechanical there are many good uses for many devices. LVDTs are robust and offer outstanding repetition which means they are suitable for use in a range of industries and in applications which involve ongoing measurements. LVDTs are used in applications such as the following:
Power turbines, hydraulics, aircrafts, satellites, nuclear reactors, factory automation, servo mechanisms, weight sensitive applications, general industrial application, process and control, materials testing.
In applications where both accuracy and reliability are key; an LVDT is well suited and recommended. Some benefits to choosing LVDTs are:
Friction Free – they are non-contacting and therefore friction free meaning they offer long life
Fast Response – the fast response time of the LVDT means that time can be managed effectively during use.
Robust – being robust means that LVDTs can be used in extreme applications and environments.
Versatile – different configurations are available to suit different applications.
Considerations when choosing should be on size as AC versions are much smaller body length than DC, and also temperature.