Position Sensor 101: Types and Working Principle of Linear Sensors


Position sensors are a vital component of many industrial processing set-ups and monitoring equipment. Sensors are typically needed for quality control and ensuring safety. In some commercial applications like consumer products, sensors provide the framework for some functions.

How does a position sensor work?

The type of position sensor also dictates its working principle. There are several kinds of position sensors categorised according to how they measure and detect an object’s displacement as well as the method of producing an output signal. A linear voltage differential transformer is perhaps the most identifiable type of Linear position sensor. An LVDT is a non-contact sensor which converts the linear movement of a body into electrical signals. It consists of three coils wound around a core encased in a tube. The core is freely moving but connected to the target object.

What kind of position sensors are there?

You can identify a linear sensor according to its sensing technology. Industrial buyers distinguish between the following sensor categories to find the most appropriate selection for the intended application:

• Capacitance sensor. It is a type of non-contact position sensor which works by determining the difference in voltage applied to the sensor and the target object.

• Linear potentiometers. Also known as a linear transducer, it produces a resistive output which is directly proportional to the target object’s displacement.

• Eddy current sensors. Another non-contact type of linear sensor which uses the same working principle as an LVDT.

• Photoelectric sensors. Just as the name suggests, a photoelectric sensor uses fibre optics and optical triangulation to detect object displacement.

• Hall-effect sensors. This type of sensor uses magnetic fields to measure movement.

• Ultrasonic sensors. This type of sensor measures displacement through sound projection and detection.

You can further classify sensors according to the type of movement they detect. There are rotary sensors and angle sensors which detect rotational and angular motion respectively. Sensors are also categorised as submersible if they are used in applications which require submersion in liquid.

Positek specialises in manufacturing sensors using their patented non-contact technology suitable for various industrial applications. Their range of linear, rotary, submersible, and tilt angle sensors have the most robust fabrication capable of withstanding even the harshest working conditions. With proven durability and robustness, Positek’s sensors have an unlimited lifecycle and measurement repeatability.

Can Positek build a sensor to my size requirements?

In some industrial applications, it is possible to require sensors with unique specifications not found in pre-fabricated products. Positek understands that manufacturing a sensor with the exact size requirements is vital to maintaining the integrity of the application. If you need custom sensors, Positek can build the sensor you need by letting you get in touch with their team of engineers ready to assist you with the design process. With over 25 years of experience in building high-quality sensors, every customer is guaranteed the same attention to detail and impeccable craftsmanship.

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