There are several common sensors

There are several common sensors

There are several common sensors, a lot of scientific research need to use sensors, sensors play a big role, sensors are a detection device, can feel the measured information, and can feel the information, then there are several common sensors?

There are several common sensors1

Sensors are a detection device, in daily life has been very widely used. Mainly by the sensitive components, conversion components, transformation circuits and auxiliary power supply, with miniaturization, digitalization, intelligence and other characteristics, sensors in the field of automatic control have an important role. The types of sensors are also extremely diverse, so what kinds of sensors? Next to give you an introduction.

According to the use can be divided into pressure-sensitive and force-sensitive sensors, position sensors, liquid level sensors, energy sensors, speed sensors, acceleration sensors, ray radiation sensors, thermal sensors.

According to the principle of operation can be divided into vibration sensors, moisture-sensitive sensors, magnetic sensors, gas-sensitive sensors, vacuum sensors, biosensors and so on.

According to the output signal can be divided into analog sensors, digital sensors, digital sensors, switch sensors.

According to its manufacturing process can be divided into integrated sensors, thin-film sensors, thick-film sensors, ceramic sensors

Sensors are categorized into:

1, according to the physical quantity of the sensor is categorized, can be divided into displacement, force, speed, temperature, flow, and other sensors;

2, by the Sensor working principle classification, can be divided into resistance, capacitance, inductance, voltage, Hall, photoelectric, grating, thermocouple and other sensors;

3, according to the nature of the sensor's output signal classification, can be divided into switching sensors, analog sensors, digital sensors of pulse or code. Vehicle sensors are automotive computer system input device, which runs the car in a variety of operating conditions, such as vehicle speed, temperature of various media, engine operating conditions, etc., into electrical signals to the computer, so that the engine is in a better working condition.

There are several common sensors2

A photoelectric sensor

The photoelectric sensor is a device that converts light signals into electrical signals. Its working principle is based on the photoelectric effect. The photoelectric effect refers to the light irradiation in some substances, the material of the electronic absorption of photon energy and the corresponding electrical phenomenon. According to the photoelectric effect phenomenon of the photoelectric effect is divided into three categories: external photoelectric effect, internal photoelectric effect and photoelectric effect. Photoelectric devices are phototransistors, photomultiplier tubes, photoresistors, photosensitive diodes, photosensitive transistors, photovoltaic batteries and so on.

Photoelectric sensors have a high resolution, short response time, long detection distance, less restriction on the detection of objects and so on. Especially worth mentioning is that it can achieve color discrimination. The reflectance and absorbance of light formed through the detection object vary according to the wavelength of the light being cast and the 'color combination of the detection object. Using this property, the color of the detection object can be detected.

The proximity sensor

The proximity sensor can be non-contact sensing detection, so there will be no wear and tear as well as damage to the detection object, and no sparks, noise. Because it is a non-contact output method, so the service life is long, almost no impact on the life of the contact.

Proximity sensors are different from other detection methods in that they are suitable for use in oil and water environments, and are virtually unaffected by stains and oil and water on the test object.

Among other things, proximity sensors themselves can only detect metal objects at close range and without contact. The most important feature of the range-altering spring-loaded rod device is that it can overload the sensing range range of the contact. Spring loaded pistons, probes, and buttons are generally used to contact the product and then detect whether the product is in place, positioned accurately, and to verify the product being measured.

Third, fiber optic sensors

The use of optical fiber to develop fiber optic sensors began in 1977, the technology was introduced that has caused great interest in the current fiber optic sensors have been developed rapidly.

Because the fiber itself is a dielectric, and sensitive components can also be made of dielectric materials, so the fiber optic sensor has a good electrical insulation, fiber optic surface can withstand 80kV/20cm voltage, especially for high-voltage power supply systems and large-capacity motor testing.

The use of optical fiber can constitute a wide variety of sensors, so some people say that the fiber optic sensor is wan energy sensor. It can measure many physical quantities, applications throughout the military, commercial, civilian, medical, industrial control and other fields. One thing to be clear is that traditional sensors are based on mechanical-electrical measurements, while fiber optic sensors are based on optical measurements.

Fourth, the displacement sensor

Displacement sensor is the object's motion displacement into a measurable electrical quantity of a device. Usually used for the deformation, vibration, displacement, position, size and other physical quantities are not easy to quantitatively detect and deal with the conversion into easy to quantitatively detect, easy to make the information transmission and processing of electrical quantities.

Displacement sensors are a wide variety of applications in recent years, more and more innovative technologies are beginning to be used in the sensor. For example, based on fiber optic technology, time grid technology, OEM's LVDT technology, ultrasonic technology, magnetostrictive technology, etc. As a result of technological advances, the performance of various sensors has increased dramatically, and the cost has been significantly reduced.

V. Hall Effect Sensors

Rotary Hall effect sensors generally do not use any moving parts, this semiconductor-based sensor combines a Hall effect sensing element with circuitry to provide an analog output signal that corresponds to a change in the rotating magnetic field. Two output options are available, analog or pulse width modulation (PWM).

Among other things, the linear Hall effect sensor measures the linear motion of the magnetic field, rather than rotation. The sensor is said to be programmable for a set output voltage that is proportional for a given distance traveled.

Up to now, the technology related to Hall sensors is still in the process of progress, programmable Hall sensors, smart Hall elements and miniature Hall sensors will have a good market prospect.

There are several common types of sensors3

What is a sensor?

Sensor (Transducer/Sensor) is a detection device, can feel the measured information, and can feel the information, according to a certain law, transformed into electrical signals or other required forms of information output to meet the transmission of information, processing, storage, display, recording and control requirements.

The characteristics of the sensor include miniaturization, digitalization, intelligence, multifunctionality, systematization, networking. It is the primary link to realize automatic detection and automatic control. The existence and development of sensors, so that the object has a sense of touch, taste and smell and other senses so that the object slowly become alive.

Usually according to its basic sensing function is divided into heat-sensitive components, light-sensitive components, gas-sensitive components, force-sensitive components, magnetic components, moisture-sensitive components, acoustic components, radiation-sensitive components, color-sensitive components and taste-sensitive components and other dozens of categories. This chapter will focus on two types of sensors: temperature sensors and pressure sensors.

Temperature Sensors

The role of temperature sensors is to feel the temperature and will be converted to electrical signals, transmitted to the processing organization, in order to achieve the corresponding display or control. Industrial use of temperature sensors are mainly four categories: thermistor temperature sensors, RTD temperature sensors, thermocouple temperature sensors and integrated circuit temperature sensors.

Thermistor Temperature Sensors

Thermistors are characterized by temperature sensitivity, different temperatures show different resistance values, which are divided into positive temperature coefficient thermistor (PTC) and negative temperature coefficient thermistor (NTC) two categories. PTC thermistors are divided into two categories: positive temperature coefficient thermistors (PTC) and negative temperature coefficient thermistors (NTC).

The main material of positive temperature coefficient thermistor is sintered by barium titanate doped with rare earth elements; the main material of negative temperature coefficient thermistor is sintered by manganese, cobalt, nickel, iron, copper and other transition metal oxides.

Thermistor temperature sensor probe is a negative temperature coefficient thermistor (NTC) after the formation of the package. Encapsulated in the form of resin encapsulation, copper shell encapsulation, stainless steel shell encapsulation, etc., commonly used in household air conditioning, automotive air conditioning, refrigerators, cabinets, water heaters, water dispensers, heaters, dryers, etc. on the measurement and control of temperature.

Thermoelectric Temperature Sensors

RTDs are resistors whose resistance value changes with temperature. Thermal resistance temperature sensor is the use of conductors (such as metal platinum, copper, iron, nickel) resistance value with the principle of temperature change for temperature measurement of a sensor.

RTDs are widely used to measure temperatures in the range of -200~+850℃, and in a few cases, the low temperature can be measured up to 1K (-272.15℃) and the high temperature up to 1000℃.

RTD sensor consists of RTD, connecting wire and display instrument, RTD can also be connected with temperature transmitter, the temperature will be converted to standard current signal output.

The materials used to manufacture RTDs should have the largest possible and stable resistance temperature coefficient and resistivity, the output is best linear, stable physical and chemical properties, good reproducibility. At present, the most commonly used RTDs are two metal materials: platinum RTDs and copper RTDs.

Platinum RTD, mainly Pt100 and Pt1000 two kinds, Pt after 100 and 1000 refers to 0 ℃ when the resistance value of 1002 and 1000; Copper RTD, there are two kinds of Cu50 and Cu100, Cu after 50 and 100 refers to 0 ℃ when the resistance value of 50 and 1000.