A linear variable differential transformer (LVDT), also known as a linear transducer is a type of electric transformer used in measuring linear displacement. These devices are contactless or frictionless which makes them last a long time when used properly. Depending on the output type, there are linear transducers that can operate at extremely high temperatures. They can also be designed to function in harsh environments, even in high shock and pressure applications.
Development of Linear Displacement Transducer
Earlier linear variable differential transformer models were primarily used by the military. It was preferred in this type of application because of the inherent ruggedness of the device as well as the high resolution of measurement. A couple of decades later, further improvements were made in the construction and performance of linear transducers. By this time, LVDT devices were primarily used in industrial applications.
In the 1970s, the improvements made to linear transducers focused on electronics. This further conditioned the signal and increased the accuracy of the device. In the 1980s, integrated circuits with complete electronic functions became available. This innovation made LVDTs more practical to design, coupled with good performance.
Linear transducers throughout time have developed along with other technology. This opened opportunities for applications beyond industrial and agricultural machines. These days, transducers are used in a myriad of applications that range from machines used in production to sophisticated aircraft and satellites.
Modern application of LVDT Sensors
In only a span of 60 years, LVDTs have become widely used in land, air, water, and space applications. New techniques in construction have significantly reduced production cost whilst improving overall performance. Here are examples where LVDT linear transducers are used today:
- Hydraulic applications. Hydraulic machines have cylinders that facilitate movement. The LVDT provides position feedback in these machines by monitoring the performance accuracy of actuators and cylinders. One specific example is a robotic arm. The position feedback coming from the LVDT tells the control system when to stop. This allows the robotic arm to control functions without damaging any components of the machine.
- Petroleum extraction. LVDT linear sensors are widely used in downhole drilling equipment. It provides position information for various aspects of the drilling machine withstanding high temperatures and high pressure. This is applicable for deep-sea oil drilling.
- Other uses of LVDT in modern technology. The ever-expanding versatility of LVDT makes them ideally applicable to just about any type of machine. You can find linear sensors in ATM machines to ensure that money is dispensed correctly, military and commercial aircraft, agricultural machines responsible for food production, factory machines for industrial production, construction machines, satellite and spacecraft, and robotic components used in research and medicine.
It is safe to assume that there will be more practical uses for LVDT in the coming years. New developments, manufacturing methods and availability of materials will add to the versatility and usefulness of sensor technology.