Comparing Positek's Linear Position Sensor and LVDTs

Positek is a leading manufacturer of position sensors using a patented non-contact inductive technology. Their linear position sensors have the benefits of modern LVDTs but with increased reliability, robustness, and durability.

Positek is a leading manufacturer of position sensors using a patented non-contact inductive technology. Their linear position sensors have the benefits of modern LVDTs but with increased reliability, robustness, and durability.

Contacting and non-contacting sensor design are two broad categories for position sensors. Simply put, a contacting sensor is one where the device gets in contact with the target object to read position displacement. On the other hand, a non-contacting position sensor does not directly get in touch with the target object while measuring movement.

One example of a contacting position sensor is a potentiometer. Potentiometers are some of the simplest and easiest sensors to operate and use. It is a resistor with three terminals where the sliding contact creates the resistance proportional to the object's movement. Because if this working principle, potentiometers are more sensitive to the effects of wear and tear as well as other environmental elements. Although potentiometers are economical and readily available, they are not suitable for industrial applications.

The advantages of a modern LVDT

A linear variable differential transducer or LVDT specifically measures linear movement. This device works by converting mechanical motion into an electric signal or AC voltage. The internal composition of an LVDT consists of three coils. The primary winding coil is in the middle of two identical secondary winding coils. All three coils are wound around a tube or core which is typically reinforced to resist moisture. These coils and tube are then hermetically sealed inside a stainless steel housing.

The core inside the coil is free moving and coupled mechanically to the target object while the coil structure remains stationary and does not get in contact with the moving object. Some of the benefits of using an LVDT over other types of position sensors are:

• Frictionless operation. While the sensor operates, the coil and the core does not get in contact, hence the absence of friction. For applications where the target object is subject to vibration and excessive movement, an LVDT's frictionless operation is advantageous.

• Limitless measurement resolution. One of the outstanding features of an LVDT is how it can measure infinitely small changes in position. The capability of an LVDT to measure a limitless number of resolution may only be hindered by noise from the signal conditioner or a limited output display resolution.

• Outstanding mechanical life. Due to its non-contact working principle, an LVDT is not vulnerable to wear and tear. This characteristic is essential for applications that require reliability such as in aircraft and aerospace vehicles. LVDTs are also ideal for most industrial applications such as factory automation and process control.

• Environmental robustness. LVDTs are constructed using rugged and durable materials though techniques that ensure resistance to extreme environmental conditions. In applications where the device is subject to high amounts of moisture, flammable, or corrosive compounds, hermetic sealing is available for protection. For applications that require intrinsically safe devices, there are LVDTs manufactured to comply with standards set for intrinsic safety.

These are only a few of the desirable characteristics of an LVDT which makes it one of the most sought-after position sensors today. Moreover, LVDTs have also become more affordable to produce, hence no longer limits industrial buyers from choosing an LVDT while at the same time keeping the assembly cost within an attainable budget.

Linear position sensor by Positek

Positek manufactures linear position sensors with all of the benefits of a traditional LVDT, but with improved reliability and better stroke to length ratio. One of the challenges in using an LVDT is that it is not always compatible with compact or confined spaces. By reducing the coil assembly and producing a position sensor which operates using only one coil, Positek's linear displacement sensors lend well in applications with limited space for construction.

Position sensor customisation

With Positek, every industrial buyer looking for a particular type of position sensor has the added advantage of requesting for custom design and build. Although there is an extensive inventory to choose from, you can still ask for exact sensor specification to be manufactured by our dedicated engineering team.

The process begins with a consultation where you can collaborate with the engineer regarding the design. Once you've approved the final design, the sensor will be manufactured and delivered within several days. Customisation is an excellent option when an application is unique and highly specific. You won't have to worry about recalibrating or adjusting a sensor if you allow Positek to build the exact sensor you need.