Resistive sensors, along with corresponding measuring circuits, are used to construct measuring instruments for force, pressure, weight, displacement, acceleration, torque, etc. These instruments are indispensable tools for automatic weighing, process monitoring, and production automation in sectors such as metallurgy, power, transportation, petrochemicals, commerce, biomedicine, and national defense.
Classification of resistive sensors
According to their working principle, resistive sensors can be classified into: resistance strain gauge sensors, potentiometer sensors, resistance temperature detectors (RTD) sensors, semiconductor resistance temperature detectors (RTD) sensors, etc.
Working principle of resistive sensors
All metallic objects have a certain resistance, the value of which varies depending on the type of metal. For the same material, the thinner or more delicate it is, the greater its resistance. When an external force is applied, if the metal becomes thinner or longer, the resistance increases; if it becomes thicker or shorter, the resistance decreases. If a metallic resistor is installed on an object undergoing strain, when the object expands or contracts, the metal also expands or contracts proportionally, thus causing a corresponding change in its resistance.
Ordinary resistance sensors are evolving towards higher precision, ease of use, and labor-saving operation. A resistance sensor is a sensitive element that directly converts strain signals into electrical signals, making it suitable for manufacturing various sensors. Resistance sensors are primarily used for measuring force, pressure, acceleration, displacement, torque, etc.
In the past, resistance sensors were mainly used in experimental research, and are frequently used in industrial inspection and weighing and control of production lines. Their use in medicine and bioengineering is also increasing. During use, sensors are typically required to have stable electrical signal output, fast response speed, small size, and light weight, all of which resistance sensors meet. However, resistance sensors still have shortcomings in several areas, including temperature, creep, hysteresis, and elastic modulus self-compensation. But with the advent of superior materials such as phenolic resins, epoxy-phenolic resins, and polyimide resins, resistance sensors with improved performance have a brighter future.
