Photoelectric Sensors

1 Overview Editing

The photoelectric detection method has the advantages of high accuracy, fast response, non-contact, etc., and more measurable parameters, simple structure of the sensor, and flexible and diverse forms. Therefore, the photoelectric sensor is widely used in detection and control.

Photoelectric sensors are the key components for photoelectric conversion in various photoelectric detection systems. They are devices that convert light signals (infrared, visible, and ultraviolet laser light) into electrical signals.

The photoelectric sensor is a photoelectric device as a conversion element sensor. It can be used to detect non-electrical quantities that directly cause light quantity changes, such as light intensity, illuminance, radiation temperature measurement, gas composition analysis, etc.; it can also be used to detect other non-electrical energy that can be converted into light quantity changes, such as part diameter, surface roughness, strain , displacement, vibration, speed, acceleration, as well as the shape and working status of the object. Photoelectric sensors have the characteristics of non-contact, fast response, reliable performance, and are widely used in industrial automation devices and robots. The emergence of new optoelectronic devices, especially the birth of CCD image sensors, has created a new page for the further application of photoelectric sensors.

2 Principle Editing

The optical measurement and control system made by the different effects of the luminous flux on the photoelectric element is various, and the output characteristics of the photoelectric element (optical measurement and control system) can be divided into two types, ie, the analog photoelectric sensor and the pulse (switch) optical Sensors. Analog photoelectric sensors convert the measured photocurrent into a continuously changing photocurrent, which is a single-valued relationship with the measurement. The analog photoelectric sensor can be classified into a transmission (absorption) type according to the measured (detection target object) method. Diffuse reflection, shading (beam block) three categories. The so-called transmissive refers to the measured object placed in the optical path, light emitted by the light source energy through the measured object, part of the absorption, the transmitted light is projected to On the photoelectric element, the so-called diffuse reflection means that the light emitted from the constant light source is projected on the object to be measured, and then reflected from the surface of the object to be measured and then projected on the photoelectric element; the so-called shading refers to when the light flux emitted by the light source passes through the object to be measured. The light covers part of it, causing the flux of light projected onto the optoelectronic component to change. The degree of change is related to the position of the object being measured in the light path.

Photodiodes are the most common light sensors. The appearance of the photodiode is the same as that of a normal diode. When there is no light, it is the same as an ordinary diode. The reverse current is small (<μA), which is called the dark current of the photodiode. When light is present, carriers are excited. Generate electron-holes, known as photoelectric

Photoelectric Sensors

Carriers. Under the action of an external electric field, photocarriers participate in conduction, forming a much larger reverse current than a dark current, which is called photocurrent. The size of the photocurrent is proportional to the light intensity, so that an electrical signal that changes with the light intensity can be obtained on the load resistance.

In addition to photodiodes that have the ability to convert optical signals into electrical signals, phototransistors also have the ability to amplify electrical signals. The appearance of the phototransistor is almost the same as that of a normal triode. In general, the phototransistor only leads to two poles—the emitter and the collector. The base is not led out. The shell also opens the window so that the light can enter. In order to increase the illumination, the base area is made large, the emission area is small, and the incident light is mainly absorbed by the base area. During operation, the collector junction is reversed and the emitter junction is positive. In the absence of light, the current flowing through the tube is the dark current Iceo=(1+β)Icbo (small), which is less than the penetration current of a normal triode; when there is light, a large number of electron-hole pairs are excited, making The current Ib generated by the base increases, the current flowing through the tube at the moment is called the photocurrent, and the collector current Ic=(1+β)Ib. It can be seen that the phototransistor has a higher sensitivity than the photodiode.

working principle

Photoelectric sensors are controlled by converting changes in light intensity into changes in electrical signals.

Photoelectric sensors in general, there are three parts, they are divided into: transmitter, receiver and detection circuit.

The transmitter is aimed at the target emitting light beam. The emitted light beam is generally derived from a semiconductor light source, a light emitting diode (LED), a laser diode, and an infrared emitting diode. The beam is continuously emitted, or the pulse width is changed. The receiver consists of a photodiode, a phototransistor, and a photocell. In front of the receiver, optical elements such as lenses and apertures are mounted. Behind it is a detection circuit that can filter out the valid signal and apply the signal.

In addition, there are emission plates and optical fibers in the structural elements of the photoelectric switch.

Classification and working methods

(1) Trough type photoelectric sensor

An optical transmitter and a receiver are mounted face-to-face on one side of a slot to form a slot-shaped optoelectronic. The light emitter emits infrared light or visible light, and the light receiver can receive light in the unimpeded condition. However, when the detected object passes through the slot, the light is blocked, the photoelectric switch is activated, a switch control signal is output, and the load current is cut off or switched on to complete a control action. The detection distance of the trough switch is generally only a few centimeters because of the limitation of the overall structure.

(2) On-beam photoelectric sensor, if the light emitter and the light receiver are separated, the detection distance can be increased, and one light emitter and one light receiver constitute a split-type photoelectric switch, which is abbreviated as an on-beam photoelectric switch. The detection distance of the shoot-type photoelectric switch can reach several meters or even tens of meters. When using a photoelectric switch, the light emitter and the light receiver are respectively installed on both sides of the path through which the object passes, and the light path is blocked when the detected object passes through. The light receiver outputs a switch control signal when it passes through.

(3) Reflector type photoelectric switch

The light emitter and the light receiver are installed in the same device, and a reflector is installed at the front, and the photoelectric control function is accomplished by using the principle of reflection, which is called a reflector reflective (or reflective mirror) photoelectric switch. Under normal circumstances, the light source emitted by the light reflector is reflected back by the reflector and then received by the light receiver; once the detected object blocks the light path and the light receiver does not receive light, the photoelectric switch activates and outputs a switch control signal.

(4) Diffuse reflective photoelectric switch

In the detection head of the diffuse reflection type photoelectric switch, there is also a light emitter and a light receiver, but there is no reflector in front of the diffuse reflection type photoelectric switch. The light emitter emitted by the light emitter is normally not found. In the detection, when the detection object passes the light is blocked, and the light part is reflected back, the light receiver receives the light signal and outputs a switch signal.

No reason for signal output

The first thing to consider is the problem of wiring or configuration. For the shoot-type photoelectric sensor must be combined by the light emitter and receiver, both ends need to supply power; and the retro-reflective type must be used in combination with the sensor probe and the retro-reflective panel; at the same time, the user must provide a stable power supply to the sensor. For DC power supply, the positive and negative poles must be confirmed. If the positive and negative poles are connected incorrectly, the output signal will not be generated.

The above reason analysis is the consideration of the photoelectric sensor itself. We also need to consider the problem of detecting the position of the object. If the detected object is not in the detection area, such detection is futile. The detection object must be within the area that the sensor can detect, that is, within the range that the photoelectricity can sense. Secondly, it is necessary to consider whether the optical axis of the sensor is aligned or not. The optical axis of the emitter and receiver sections of the injection type must be aligned, and the corresponding retroreflective probe section and the optical axis of the reflector must be aligned. It is also necessary to consider whether the detection object conforms to the criteria of the standard detection object or the minimum detection object, and the detection object cannot be smaller than the minimum detection object standard, so as to avoid the result that the radiation type and the reflection type cannot detect the transparent object well, like the reflection type There is a requirement to detect the color of the object, the darker the color, the closer the detection distance.

If the above conditions can be clearly eliminated, what we need to do is to detect environmental disturbances. Such as light intensity can not exceed the rated range; if the scene environment has dust, we need to regularly clean the surface of the photoelectric sensor probe; or multiple sensors are closely installed to interfere with each other; there is a greater impact is electrical interference, if there is High-power equipment must have appropriate anti-jamming measures when generating interference. If you have done the above-mentioned investigations one by one, these factors can be clearly excluded or there is no signal output, it is recommended to return to the factory inspection and judgment. [1]

Structural analysis

Photoelectric sensors are usually composed of three parts, they are: transmitter, receiver and detection circuit.

The transmitter has a calibration lens that focuses the light towards the receiver and the receiver output cable connects the device to a vacuum tube amplifier. Inside the metal cylinder there is a small incandescent lamp as the light source. These small and sturdy incandescent light sensors are the prototypes of today's photoelectric sensors.

The receiver consists of a photodiode, a phototransistor and a photocell. Photodiodes are now the most common sensors. The photoelectric sensor photodiode has the same appearance as a general diode, except that a glass-embedded window is opened on the shell to facilitate light injection. In order to increase the light-receiving area, the area of ​​the PN junction is made larger, and the photodiode is operated. In the reverse biased working state, and in series with the load resistance, when there is no light, it is the same as ordinary diodes. The reverse current is very small, called the dark current of the photodiode; when there is light, the carriers are Excitation generates electron-holes called photocarriers.

In addition, there are emission plates and optical fibers in the structural components of the photoelectric sensor. The corner reflector is a structurally robust launcher consisting of a very small triangular pyramid reflective material that allows the light beam to accurately return from the reflector. It can change the emission angle in the range from 0 to 25 with the optical axis, so that the beam is reflected almost from an emission line and still returns from this reflection line. [2]

Types of

(1) Trough type photoelectric sensor

An optical transmitter and a receiver mounted face-to-face on both sides of a slot are slot-shaped optoelectronics. The light emitter emits infrared light or visible light, and the light receiver can receive light in the unimpeded condition. However, when the detected object passes through the slot, the light is blocked and the photoelectric switch is activated. A switch control signal is output, and the load current is cut off or turned on to complete one control action. The detection distance of the trough switch is generally only a few centimeters because of the limitation of the overall structure. [3]

(2) Photoelectric sensor

If the light emitter and the light receiver are separated, the detection distance can be increased. A photoelectric switch consisting of a light emitter and a light receiver is called a split-shot photoelectric switch, or short-shot photoelectric switch. Its detection distance can reach several meters or even tens of meters. When in use, the light emitter and the light receiver are respectively installed on both sides of the path through which the detection object passes. When the detection object passes, the light path is blocked, and the light receiver operates to output a switch control signal.

(3) Reflector type photoelectric switch

The light emitter and the light receiver are mounted in the same device, a reflector is installed in front of it, and a photoelectric reflection switch (or mirror reflection type) photoelectric switch that uses the principle of reflection to complete the photoelectric control is used. Under normal circumstances, the light emitted by the light emitter is reflected back by the reflector and received by the light receiver. Once the light path is blocked by the detection object and the light receiver does not receive light, the photoelectric switch activates and outputs a switch control signal.

(4) Diffuse reflective photoelectric switch

Its detector head is also equipped with a light emitter and a light receiver, but there is no reflector in front of it. The light emitter emitted by the light emitter is normally not found. When the test object passes the light is blocked, and the light part is reflected back, the light receiver receives the signal and outputs a switch signal.

3 Category Editor

Standard type

1) Diffuse type: General type or Energy type (-8), Focus type (-8-H), Background suppression type (-8-H)

Photoelectric Sensors

With background analysis function (-8-HW)

2) Reflector type: General type (-6), with polarization filter function type (-54, -55), with transparent body detection type (-54-G), with foreground suppression function type (-54-V)

3) Shooting type

4) Groove type

5) Optical fiber sensor: plastic fiber type, glass fiber type

6) color mark sensor, color sensor, fluorescence sensor

7) Optical Communication

8) Laser Ranging: Principle of Triangle Reflection, Principle of Phase Difference, Principle of Time Difference

9) Raster

10) Explosion-proof/flameproof type

Security type

1) Security on Optoelectronics

2) Safety grating

3) Safety light curtain

4) Safety Controller

Gating type

1) Radar sensor: area detection type

Radar sensor

2) Active sensors: single beam type, multi beam type, area detection type

3) Passive Sensors: Area Detection

4) Elevator light curtain

5) General-purpose photoelectric: trough, injection type, etc.

Specialty

1 long detection distance [4]

If a detection distance of 10 m or more is left in the beam type, other detection methods (magnetism, ultrasonic waves, etc.) cannot be detected over a long distance.

2 less restrictions on detection of objects

Since the principle of detection is light blocking and reflection caused by the detection of objects, the detection object is not limited to the metal like the proximity sensor, and it can detect almost all objects such as glass, plastic, wood, and liquid.

3 Short response time

The light itself is high speed, and the circuit of the sensor is composed of electronic parts, so it does not include mechanical working time, and the response time is very short.

4 high resolution

The high resolution can be achieved by using advanced design techniques to focus the projected light beam at a small spot or by forming a special light receiving optical system. Can also detect small objects and high-precision position detection.

5 can achieve non-contact detection

The detection can be performed without mechanically contacting the detection object, and thus the detection object and the sensor are not damaged. Therefore, the sensor can be used for a long period of time.

6 can achieve color discrimination

The reflectivity and absorptivity of the light formed by the detection object differ depending on the combination of the wavelength of the light to be cast and the color of the detection object. With this property, the color of the detected object can be detected.

7 easy to adjust

In the type of projected visible light, the cast light beam is visible to the eye, facilitating the adjustment of the position of the detected object.

application

First, smoke turbidity monitor

Preventing industrial smoke and dust pollution is one of the important tasks of environmental protection. In order to eliminate industrial smoke and dust pollution, we must first know the amount of smoke and dust emissions, so we must monitor the smoke source, automatically display and exceed the standard alarm. Flue dust turbidity in the flue is detected by the size of the change in light transmission through the flue. If the turbidity of the flue gas increases, the light emitted by the light source is increased by the absorption and refraction of smoke particles, and the light reaching the photodetector is reduced. Therefore, the intensity of the output signal of the photodetector can reflect the change of the turbidity of the flue.

Second, the bar code scanning pen

When the scanning tip moves on the bar code, if a black line is encountered, the light of the light emitting diode will be absorbed by the black line, and the phototransistor will not receive the reflected light, and will be in a high impedance and in an off state. When a white interval is encountered, the light emitted by the light emitting diode is reflected to the base of the phototransistor, and the phototransistor generates a photocurrent and conducts. After the entire bar code is scanned, the phototransistor transforms the bar code into electrical pulse signals. After the signal is amplified and shaped, the pulse train is formed. The signal processing is then processed by the computer to complete the identification of the bar code information.
Third, the product counter

When the product is running on the conveyor belt, it constantly blocks the light path from the light source to the photosensor, so that the photoelectric pulse circuit generates one electrical pulse signal. Once the product is shaded once, the photoelectric sensor circuit generates a pulse signal. Therefore, the output pulse number represents the number of products. The pulse is counted by the counting circuit and displayed by the display circuit.

Fourth, photoelectric smoke alarm

When there is no smoke, the light emitted by the light emitting diodes travels in a straight line, and the phototransistor does not receive signals. When there is no output and there is smoke, the light emitted by the light emitting diodes is refracted by the smoke particles, so that the triode receives the light, a signal is output, and an alarm is issued.

Fifth, measuring speed

Applying two colors of black and white on the rotating shaft of the motor, the reflected light and the non-reflected light alternately appear when the motor rotates. The photoelectric sensor intermittently receives the reflected signal of the light and outputs the intermittent electrical signal, which is amplified by the amplifier and the shaping circuit. The plastic output square wave signal, and finally the output speed of the motor is output by the electronic digital display.

Sixth, photocells in photoelectric detection and automatic control applications

When photocells are used as photodetectors, their basic principles are the same as photodiodes, but their basic structure and manufacturing process are not exactly the same. Since the photovoltaic cell does not require an applied voltage during operation, it has a high photoelectric conversion efficiency, a wide spectral range, good frequency characteristics, and low noise, and it has been widely used for photoelectric readout, photoelectric coupling, raster distance measurement, laser collimation, and movie playback. , UV light monitors, and flameout protection devices for gas turbines.

Applications

Photoelectric sensor applied to laser weapons

Because photoelectric sensors are particularly sensitive to infrared radiation, or visible light, or both, they are more likely to be the target of laser attacks. In addition, the electronic system and the sensor itself are also very vulnerable to thermal noise and electromagnetic noise generated by the laser and do not work properly. Laser weapons on the battlefield attack the photoelectric sensor in the following ways: The sensor is “blind” with a laser beam of appropriate energy, making it impossible to detect or continue to track the target that has been detected. Or, if the sensor is guiding the weapon to the target, blinding will cause it to lose its target. In summary, because sensors play a more and more important role on the battlefield and are vulnerable to laser attacks, they have become the preferred target for low-energy laser weapons [5] .

Photoelectric sensor applied to automatic meter reading system

With the development of microelectronic technology, sensor technology, computer technology and modern communication technology, photoelectric sensors can be used to develop automatic meter reading systems. The aluminum plate of the electric energy meter is rotated by the torque generated by the eddy current and the magnetic field. The use of photoelectric sensors converts the number of revolutions of an aluminum disk into pulses. Such as: in the rotating bright aluminum plate is partially blackened, coupled with a reflective optoelectronic emission receiving tube, when the aluminum plate rotates, it will produce a pulse in the local black place, and the number of rotation of the aluminum plate can be sampled Converted to the corresponding number of pulses, and through the optocoupler isolation circuit, sent to the CPU's T0 port count processing. The use of optocouplers can effectively prevent interference signals from entering the microcomputer. Combined with other transmission methods can form an automatic meter reading system. [6]

Photoelectric sensor used to monitor smoke pollution

A photoelectric sensor is a small electronic device that can detect changes in the intensity of light it receives and implement control functions by converting light intensity changes into electrical signals. Because photoelectric sensors have the characteristics of non-contact, fast response, and reliable performance, they have been widely used in industrial automation devices and robots. We can use the characteristics of photoelectric sensors to detect smoke and dust, and thus the output signal of photoelectric sensors is strong and weak. It can reflect changes in the turbidity of the flue. [7]

characteristic

1) Wide transient response range and strong harmonic measurement capability

The pros and cons of transient characteristics are an important parameter for judging whether a transformer can be used in the power system, especially with the relay protection action time. Due to the presence of iron cores, conventional electromagnetic transformers have poor response characteristics to high-frequency signals and cannot correctly reflect the transient process on the primary side. The frequency range measured by the photoelectric transformer is mainly determined by the electronic circuit part, there is no problem of core saturation, so it can accurately reflect the primary side of the transient process. It can be designed from 0.1 Hz to 1 MHz, and special bandpass can be designed to 200 MHz. The structure of the photosensor can measure the harmonics on the high voltage power line. The electromagnetic induction transformer is difficult to achieve.

2) Digital interface, strong communication capabilities

Because the photoelectric sensor transmits the optical digital signal, it is easy to interface with the communication network, and there is no measurement error in the transmission process. At the same time, with the widespread adoption of computerized protection and control equipment, photoelectric transformers can directly provide digital quantities to secondary devices. This saves the need for converters and A/D sampling parts in the original protection device, making secondary devices available. Greatly simplified and promoted research on the protection of new principles.

3) Small size, light weight, easy to upgrade, meeting the requirements of miniaturization and compactness of substations. Because photoelectric sensors rely on sensor heads and electronic circuits for signal acquisition and processing, the volume is small and the weight is generally less than 1000 kg, which is convenient. Integrated in AIS or GIS, this will greatly reduce the substation's footprint and meet the miniaturization and compactness requirements of the substation. At the same time, the photoelectric transformer is connected with the secondary equipment through a small number of optical cables, which can greatly reduce the cable trenches and cables. [8]

Market area

The main application areas of photoelectric sensors: Backlight control for car entertainment/navigation/DVD system, so that the ideal backlight brightness can be displayed under all ambient light conditions; backlit entertainment display backlight control; instrument cluster backlight control (speedometer/ Tachometer); automatic rear view mirror brightness control (usually requires two sensors, one is forward, one is backward); automatic headlights and rain sensing control (special, change according to demand); rear view camera Control (dedicated, change according to requirements). It has become one of the most effective solutions for providing more comfortable display quality. It has characteristics similar to human eyes, which is very important for automotive applications because these applications are required to be achieved in all ambient light conditions. Full backlight effect. For example, in the daytime, the user needs maximum brightness to achieve optimal visibility, but this brightness is too bright for nighttime conditions, so photosensors with good spectral response (good IR attenuation), appropriate The dynamic range and overall good output signal conditioning make it easy to automate these applications. The end user can set several threshold levels (such as low, medium, and high light), or can optionally dynamically change the backlight brightness of the sensor. This also applies to the control of the brightness of the rearview mirror of the car. Intelligent brightness management is required when the mirror is darkened and/or brightened. This can be done with ambient light sensors.

For portable applications, if the user does not change the system settings (usually brightness control), then a single display will always consume the same amount of energy. In particularly bright areas such as outdoors, users tend to increase the brightness of the display, which increases the power consumption of the system. When conditions change, such as entering a building, most users will not change the settings, so the system power consumption remains high. However, by using a light sensor, the system can automatically detect condition changes and adjust settings to ensure that the display is at optimal brightness, which in turn reduces overall power consumption. In general consumer applications, this also extends battery life. For mobile phones, notebook computers, PADs, and digital cameras, brightness control can be automatically performed by using ambient light sensor feedback to extend battery life.

Not a new idea. Photodiodes and photoresistors have been used for decades to realize this idea. The so-called new concept refers to the use of ambient light sensing while reducing unnecessary infrared and ultraviolet light. It also enables small packages to be supported while supporting the strict requirements of the automotive specification AECQ-1000, and in particular, guarantees a range of -40 degrees to + 105 degrees (2) temperature range of operation to meet the rest of the specification requirements. How to maintain working quality standards and meet the AECQ-1000's Level 2 job requirements is a challenge that is faced in all optical design solutions today. When using a light sensor or LED emitter or receiver, any optical solution faces the problem of discoloration of the package (which becomes dark or yellowish) when exposed to a constant high temperature (>+85 degrees). It is also worth mentioning that until now, all ambient light sensor applications have been confined to the cabin, and no light sensor applications have emerged in the engine compartment or outdoor environment. In fact, even with such applications, optical packages are not designed for such harsh conditions (+125 or +150 degrees). Therefore, under current optical packaging technologies, they may not be able to withstand such conditions. conditions of.

Recent advances in the development of semiconductor-like sensors and packages have led end users to have a wider choice of optical sensors. Small packages, low power consumption, high integration, and ease of use are the reasons why designers adopt more light sensors. Their applications range from consumer electronics to industrial applications and automotive.

New technologies and applications

1. 256 photocell array four-quadrant CMOS photoelectric sensors for target tracking and coordinate positioning [9-10]

Combining the traditional quadrant sensor with the rapidly developing CMOS image sensor, a four-quadrant CMOS photoelectric sensor with 256-cell photocell array using active sensing array is proposed.

The photosensitive unit of the sensor adopts an active pixel sensor (APS) design used in a CMOS image sensor, and photoelectric signal preprocessing circuit directly converts the photoelectric signal generated by the sensing into a larger amplitude in the photosensitive unit. The electrical signal output avoids the processing of weak signals and reduces the influence of noise. The sensor application array collects light signals and can directly determine the coordinate position of the target light source and achieve one-step rapid adjustment. The sensor is manufactured using standard CMOS technology. The sensor array and the signal processing circuit are integrated on the same chip, and the SOC integration and smart sensor design of the sensor can be realized. Widely used in laser sighting, guidance, tracking, search devices, precision measurement, such as laser micropositioning, displacement monitoring, precision machine tools and other areas of photoelectric control. It is a new type of integrated array four-quadrant CMOS photoelectric sensor for target tracking and coordinate positioning.

2, photosensitive quadrant array and magnetic line array compatible CMOS digital-analog sensor integrated circuit [11]

The quadrant sensors based on silicon photoelectric sensors are widely used in laser tracking guidance, displacement monitoring, precision machine tools and other fields. Silicon-based semiconductor magnetic sensors are widely used in various magnetic field meters for measuring magnetic field strength, various types of magnetic heads for reading information on magnetic media, and detectors for non-magnetic signals.

3. SPR biosensor weak signal detection using photodiode array [12]

To improve the detection capability of surface plasmon resonance biomedical sensors, and to use high-performance photodiode arrays as photoelectric conversion devices, to demonstrate and implement a detection method that can efficiently suppress noise, and to use a photodiode array device to output the characteristics of a reference noise signal Through coherent noise reduction combined with wavelet soft threshold denoising, the output signal-to-noise ratio of the SPR sensor is increased from about 40 dB to 52 dB. Experiments using SPR sensors to detect the specific binding of human immunoglobulin (IgG) molecules have shown that this method significantly improves The resolution of the SPR sensor allows it to accurately detect the faint changes in the IgG content in the sample solution at the level of 10~(-3) mg/mL, increasing the precision and resolution by more than an order of magnitude.

4, photoelectric detection sensor array in the detection of moving objects [13]

A photoelectric detection sensor array based on the coverage theory and Kalman filter algorithm. The array has the function of collecting and processing the information of objects perceived in the coverage area of ​​the array, that is, detecting and describing the existence, motion and trajectory of the sensing object [14], etc. Happening.

Forecast

According to the sensor market report of the consulting company INTECHNOCONSULTING, the global sensor market capacity in 2008 was 50.6 billion U.S. dollars, and the global sensor market in 2010 is expected to reach more than 60 billion U.S. dollars. The survey shows that Eastern Europe, Asia Pacific, and Canada have become the fastest growing areas for the sensor market, while the United States, Germany, and Japan are still the most widely distributed areas for the sensor market. Worldwide, the fastest-growing sensor market is still the automotive market, the second is the process control market, optimistic about the communications market.

Some sensor markets such as pressure sensors, temperature sensors, flow sensors, and level sensors have demonstrated the features of a mature market. Flow sensors, pressure sensors, and temperature sensors are the largest in the market, accounting for 21%, 19%, and 14% of the entire sensor market. The major growth in the sensor market comes from emerging sensors such as wireless sensors, MEMS (Micro-Electro-Mechanical Systems) sensors, and biosensors. Among them, the wireless sensor's compound annual growth rate in 2007-2010 is expected to exceed 25%.

The global sensor market is showing rapid growth among the ever-changing innovations. Relevant experts pointed out that the major technologies in the field of sensors will be extended and improved on an existing basis. Countries will compete to accelerate the development and industrialization of new generation sensors, and competition will become increasingly fierce. The development of new technologies will redefine the future market of sensors, such as the emergence and market share of new sensors such as wireless sensors, fiber optic sensors, smart sensors and metal oxide sensors.