Linear displacement sensors, also known as draw-wire sensors, string potentiometers, or string encoders, are precision devices used for measuring linear positions. They combine the advantages of angular sensors and linear displacement sensors, featuring a compact design, high precision, and large measurement range. These characteristics make them widely applicable in various scenarios where linear position measurement is required.
Overview of the Working Principle
1、Unique Encoding System
The working principle of a linear displacement sensor is based on a simple physical phenomenon: as the string is extended or retracted, the internal encoder of the sensor measures the movement of the string, providing precise position information. The core component is a rotary encoder connected to a reel or hub with a threaded design, which is wound with a stainless steel string used for measurement. Below is an internal schematic of a high-precision linear displacement sensor from Briterencoder.
Specific Working Principle
Structure: The linear displacement sensor consists of an extendable stainless steel string, a spring mechanism for retraction, and a precision rotary encoder. The stainless steel string is wound around a hub with threads, which is tightly connected to the encoder.
Operational Process: The sensor is typically mounted in a fixed position, while the string is attached to a moving object. As the object moves, the string extends or contracts accordingly. An internal spring ensures that the string remains taut, ensuring measurement accuracy.
Encoder Measurement: As the string extends or contracts, the threaded hub drives the encoder to rotate. The encoder calculates the length of the string extension based on the rotation angle, converting it into position information.
Signal Output: Depending on the type of encoder (incremental or absolute), the output signal may be a pulse sequence or a unique value representing the absolute position. Incremental encoders output a series of pulses, each representing a certain amount of displacement, while absolute encoders provide a unique code for each possible position.
Signal Output Types and Parameters
Linear displacement sensors offer digital and analog signal outputs. Digital output options include incremental rotary encoders and absolute encoders, with signals in forms such as square wave ABZ or Gray code. Analog output options include precision potentiometers, Hall effect encoders, and absolute encoders, with signals in forms such as 4-20 mA, 0-5 V, or 0-10 V. Briterencoder’s linear displacement sensors support all these signal output methods. Below are the signal output methods supported by our products.
Other common parameters for linear displacement sensors include measuring range, linearity, repeatability, resolution, string diameter specification, pull-out force, maximum reciprocating speed, weight, input resistance value, power, operating voltage, operating temperature, vibration resistance, and protection level. Briterencoder linear displacement sensors can measure data within a range of 0-10 meters, have a linearity of 0.1%, and a repeatability of 0.01%. The string is made of 0.8 mm thick stainless steel with a nylon coating, a maximum reciprocating speed of 1 m/s, and an optional IP68 waterproof or EX intrinsically safe explosion-proof version.
Application Areas
Linear displacement sensors have a wide range of applications, including but not limited to industrial automation, mechanical equipment, aerospace, transportation, and construction engineering. In AGV unmanned forklifts, linear displacement sensors are used for precise measurement of pallet lift height, ensuring the AGV forklifts can operate accurately and safely.
In conclusion, linear displacement sensors play a crucial role in scenarios requiring linear position measurement due to their high precision, large stroke, compact structure, and ease of use.
For more information or to make a purchase, please visit our official website https://briterencoder.com/. Choose Shenzhen Briter Technology Co.,Ltd and experience the excellent enjoyment of high-precision measurement!
