Displacement sensor, also known as linear sensor, is divided into inductive displacement sensor, capacitive displacement sensor, photoelectric displacement sensor, ultrasonic displacement sensor, and Hall displacement sensor.
Inductive displacement sensor is a kind of linear device belonging to metal induction, after the power is turned on, an alternating magnetic field will be generated on the sensing surface of the switch, when the metal object is close to this sensing surface, eddy current is generated in the metal and absorbs the energy of the oscillator, so that the output amplitude of the oscillator is linearly attenuated, and then according to the change of the attenuation amount to complete the purpose of non-contact detection of the object.
The inductive displacement sensor has no sliding contacts, is not affected by non-metallic factors such as dust during operation, and has low power consumption and long life, so it can be used in various harsh conditions. Displacement sensors are mainly used in the intelligent control of analog quantities in automated equipment production lines.
Displacement is a quantity related to the movement of the position of the object in the process of motion, small displacement is usually detected by strain gauge, inductance, differential transformer, eddy current, Hall sensor, large displacement is commonly measured by sensing technologies such as inductive synchronizer, grating, grating, magnetic grating, etc. Among them, grating sensors are increasingly used in machine tool processing, testing instruments and other industries because of their advantages of easy digitization, high accuracy (the current resolution can reach nanometer level), strong anti-interference ability, no human reading error, easy installation, and reliable use.
Classification of displacement sensors.
1. Classification according to the mode of exercise.
Linear displacement sensors.
Angular displacement sensor.
2. Classification according to material.
Metal film sensor, conductive plastic sensor, photoelectric sensor, magnetic sensor, metal glass uranium sensor, wirewound sensor, displacement sensor Main characteristic parameters: Nominal resistance: the resistance value indicated on the potentiometer.
Repeatability: The smaller this parameter, the better.
Resolution: The small displacement value that the displacement sensor can feed, the smaller the parameter, the better, the resolution of the conductive plastic displacement sensor is infinitesimal, and the percentage deviation of the difference between the nominal resistance value and the actual resistance value and the ratio of the nominal resistance value is allowed, which indicates the accuracy of the potentiometer. The allowable error is generally within +20% to meet the requirements, because the general displacement sensor is used in the form of partial pressure, and the size of the specific resistance has no impact on the data acquisition of the sensorLinear accuracy: the smaller the linear error, the better the life: the conductive plastic displacement sensor is more than 2 million times.
At present, the global sensor market is showing a rapid growth trend in the midst of ever-changing innovation. Relevant experts pointed out that the main technologies in the field of sensors will be extended and improved on a certain basis, and all countries will compete to accelerate the development and industrialization of a new generation of sensors, and the competition will become increasingly fierce. The development of new technologies will redefine the sensor market in the future, such as the emergence and market share expansion of new sensors such as wireless sensors, fiber optic sensors, smart sensors and metal oxidation sensors.