LVDT Transducer

What is an LVDT transducer?

An LVDT (Linear Variable Differential Transformer) transducer is also known as a linear variable displacement transducer. It converts linear movement into an electrical signal for linear position measurement.

Basic principle

An LVDT is composed of a primary solenoid coil, two secondary coils, an iron core,  a shell, and other components. When the core moves from the middle to both sides, the difference in output voltage between the two secondary coils has a linear relationship with the core movement, the position of the moving core is defined as a result. As an LVDT transducer works, the core must not move beyond the linear range of the coil, or it will generate nonlinear values, so all LVDT’s have a linear range.

basic principle of LVDT

AC-LVDT’s vs DC-LVDT’s

AC-LVDT’s. An AC-operated LVDT transducer has a strong resistance to vibration and shock and can operate over higher temperature ranges. It can also be used in smaller packages to fit in hard reaching locations.

DC-LVDT’s. A DC-operated LVDT transducer has a simple operation. The analog or digital output signal is precalibrated. There is no need for external signal conditioning equipment. It saves time and the cost as well.

Advantages of LVDT displacement sensors

LVDT transducer is one of the few displacement sensors that can work in a variety of harsh environments. The sealed LVDT, for example, is made of stainless steel and can be placed in corrosive liquids or gases. Sometimes, LVDT is required to work in extreme environments. For example, in a low-temperature environment similar to liquid nitrogen or a nuclear radiation environment. Although in most cases LVDT has an infinite working life (in theory), the working life of an LVDT in a harsh environment varies from environment to environment.

Application

A linear variable displacement transducer is widely used in aerospace, machinery, construction, textile, railway, coal, metallurgy, plastics, chemical engineering, scientific research, and other fields. It can also be used in the measurement of elongation, vibration, object thickness, expansion, and other high-tech products.

Why buy an LVDT Transducer from us?

LVDT transducers of KAIDI are ideal for the accurate monitor of the valve core position in the hydraulic control systems due to the shorter stroke lengths. Our inductive LVDT transducer fits hydraulic and solenoid valves. Importing advanced technology from BSO of Germany, our products have a wide linear range, good repeatability, and high reliability.

• None contacting. There is no physical contact between the movable core and the coil, which means there is no friction.
• Extremely long life. The shell is made of stainless steel. The zero physical contact property extends the service life.
• Infinite resolution. A KAIDI LVDT transducer can respond to the smallest movement of an iron core and produce output. The readability of external electronic devices is the only limit to resolution.
• High sensitivity. Our products are very sensitive to the axial motion of the core.
• High-pressure resistance. Static oil pressure is up to 31.5 Mpa. The protection class is up to IP65.

Key parameters of KAIDI LVDT transducers are as the following.