Tension detection was initially used primarily in safety protection scenarios, such as crane overload detection, elevator overload detection, and sling tension detection. With the increasing speed of automated production and the continuous improvement of product quality requirements, precise tension detection and control have played an increasingly important role in automated production processes. For example, industries such as steel, non-ferrous metals, paper making, printing, plastic films, and textiles all require precise and reliable tension detection and control to meet goals such as increasing production speed, ensuring stable and high-quality products, improving equipment production efficiency, and ultimately realizing intelligent production processes.

According to different working principles, tension detection sensors can be categorized into several types: capacitive, piezoelectric, fiber optic, photoelectric, surface acoustic wave, image-based, and resistive strain-based, among others. Compared with other technical solutions, tension detection sensors based on the resistive strain principle have the advantages of being mature, stable, and accurate in measurement, which is why they are currently the most widely used. Tension detection sensors based on this principle are structurally similar to common force sensors (or weighing sensors), but are specifically developed to meet the application requirements for tension detection.

The objects of tension detection are mainly wires and strips, such as yarns, steel ropes, cables, films, steel strips, and metal foils. In engineering mechanics, such constraints formed by flexible rope-like, chain-like, or strip-like bodies are called flexible constraints, also known as 'flexible cords'. Their characteristic is that they can only withstand tension, not compression, so when bearing a load, only the axial force is non-zero. The total internal force in any cross-section of a flexible cord, in an ideal catenary state, is always tangent to the curve of the flexible cord. Therefore, in general engineering applications, this is collectively referred to as the tension of the flexible cord. In engineering applications, the purposes of measuring the tension of flexible cords can generally be divided into two main categories: safety monitoring and process (quality) control.

Cable structures are widely used. Using steel wire ropes or ropes as flexible cables enables operations such as lifting and hoisting. In this process, controlling the tension of the steel wire rope is crucial to ensure the stable and accurate transport of heavy loads and the safe operation of lifting equipment. As a typical flexible cable, steel wire rope is an ideal device for transmitting tensile force. When it passes through a pulley or a pulley system, it can change the direction and magnitude of the tension. If the friction of the pulley system is neglected, the tension it experiences can be considered proportional to the load. Because steel wire ropes exhibit such characteristics as flexible devices, most lifting machinery relies on solutions involving steel wire ropes when conducting weighing, overload alarms, and torque alarms according to legal requirements. Today, tension measurement devices that support bridge-type load sensors at both ends of the trolley fixed pulley can achieve weighing system accuracy of over 0.1% FS.

In the production process of silk, fibers, fabrics, cables, and steel wire ropes, a constant force is required to wind them onto the drum. However, as the drum diameter increases during the winding process, the linear speed of the drum gradually becomes higher. Therefore, a tension measurement device (commonly a beam-type force sensor) is needed to provide tension feedback to the controller to regulate the drum's speed, ensuring a constant winding tension.

In the papermaking and printing industries, paper equipment such as rewinding machines, sizing machines, calenders, coaters, and slitting machines require precise tension control during the production process, because the tension of the paper machine affects the quality of the finished paper, papermaking efficiency, and production costs. Generally, tension detection devices are installed on the guide rollers of various drive sections of the paper machine for tension control. For example, force sensors of the shaft-type or beam-type can be installed on both sides of the running rollers for tension detection.