The inductive sensor is the use of metallic conductors and the mutual inductance of the alternating electromagnetic field principle. At the front end of the sensor detection coil generates a high frequency magnetic field, when metal objects are close to the magnetic field, eddy current metal objects internal product, leading to the decay of the magnetic field energy, energy is absorbed when the metal special body constantly gets close to the sensor sensing face and cause decay. when the attenuation reached a certain extent, the trigger sensor sensors the output signal, so as to achieve the purpose of the non-contact type of detection.

The sensing surface of the capacitive sensor is constituted by two coaxial metal electrode, the two electrodes form a capacitor, in series with the RC oscillation circuit. When the power is turned on, the RC oscillator does not oscillate, when a target is closer toward the sensor sensing surface, the increase in capacitance, and the oscillator starts to oscillate. Is converted into a switching signal by the processing of the post-stage circuit, and thus play the purpose of detecting the presence of the object exists. Capacitive sensors can detect metal objects, can also detect non-metallic objects, metal objects can get maximum distance of the action, and non-metallic objects action distance determines the dielectric constant of the material, the larger the dielectric constant of the material, available action the greater the distance.

Photoelectric sensor is a sensor that uses light to detect objects collectively, the light signal emitted by the sensor by detecting objects it shot, block and absorb longer accepted part of the detected and converted into corresponding electrical signal to the control device.

Diffuse reflection type photoelectric sensor is the transmitter and the receiver is placed integrally under normal circumstances, the receiver received less than the optical signal sent by the transmitter; when detection purified by blocking the light, and the light portion is reflected back, the receiver receives optical signal, and outputs a switch control signal.

Retro-reflective photoelectric sensor is the transmitter and the receiver is loaded into the same apparatus, and a reflective plate mounted in front thereof, and the completion of the principle of reflection of the photoelectric control role. Under normal circumstances, the light emitted by the transmitter is reflection plate reflected back is received by the receiver, blocker once the optical path of the object to be detected, the receiver detects the optical signal changes, the operation of the photoelectric sensor, outputs a switch control signal.

Beam photoelectric sensor is composed by an independent transmitter and receiver of the photoelectric sensor. Since the separation of the transmitter and receiver, the detection distance of the sensor to increase. Detection distance of up to a few meters or even tens of meters. To use the transmitter and receiver are mounted in the test object through the sides of the path, and must be aligned to create an optical path, when the subject was purified by blocking the light path, the receiver operation outputs a switching control signal.

Hall sensor is a magnetic sensor composed of voltage regulator, Hall voltage generator, differential amplifier, Schmidt trigger and output stage of Open collector. Its input is Magnetic flux density and its output is a voltage signal.

● No Institutions contact detection, difficult to damage, wear, small errors
● Not influenced by ambient environment, Work normally under harsh environment
● High accuracy of repeated detection, accurate objects positioning
● Rapid reaction frequency, suitable for fast moving object detection

● Non-contact detection, long sensing life, no damage to the objects to be detected.
● Suitable for long-distance detection of a wide range of uses.
● Applicable to a variety of subjects, also suitable to the objects which may affect ray propagating.
● High frequency response, suitable for the use of the high speed line detection.
● high detection precision, different colors can be used to distinguish.
● Use IC of independent research and development, Anti-glare interference，Anti-electromagnetic interference.

The sensing distance of the sensor will be changed slightly due to changes of ambient temperature, voltage changes surrounding conditions. Therefore, in order to make the sensor steady work, the maximum approach position of the detecting body is required to be less than the sensing distance. Using standard detection, the setting the actual sensor distance should be 80% of the operation distance or less of the distance. In addition, when the sample detecting the shape of the body is less than the standard sample or use detected body with other material, the sensing distance is shortened, the actual sensing distance is set must also be reduced.

① The detection distance of long distance proximity sensors is twice that of ordinary sensors with the same diameter.
② It has various protection circuits such as polarity protection, over current protection, surge protection, etc.
③ QWIFM long distance proximity sensors have stronger resistance to electromagnetic interference through internal processing compared to other brands' long-distance products.

Proximity sensor installation methods can be divided into flush and non-flush. The difference is that the flush can be used to sense inside the metal, and the non-flush can’t. But the sensing distance is longer when compared with the flush.

About way of leads Cable leads
About way of terminals Terminal block
About connection Connecting through socket

From the perspective of output level, the high and low levels of PNP and NPN output signals are different. From the meaning represented by PNP and NPN, the PNP type indicates that the signal output terminal outputs a high level output, and the internal switch is connected between the signal terminal and the positive electrode; The NPN type indicates that the signal output terminal outputs a low-level output, and the internal switch is connected between the signal terminal and the negative electrode.
From the perspective of load connection, PNP type sensors are used when the load is connected to the negative electrode, and NPN type sensors are used when the load is connected to the positive electrode.

When wiring two wire sensors, they must be connected in series with the load to the power supply (excluding the emission of photoelectric sensors).

Sensing distance of the proximity sensor detects the size of the body.

Detect body factors affect the sensing distance of the sensor. The nature of the material of the detecting body plays an important role, which can be described attenuation coefficient. Attenuation coefficient refers to a movement distance of a material with respect to reducing the number of iron (ST37). The attenuation coefficient is smaller, the smaller a distance for the operation of certain materials. The characteristic parameters of the capacitive sensor is the relative permittivity.

The voltage drop is when the sensor is working, the voltage obtained from the ends of the sensor or the output end.

The needde current of the sensor in working state.

The difference between the distances of proximity sensors detect body sensing surface, triggering the sensor action sensing distance away from the sensor detects body movements reversion reversion.

Repeated accuracy is in the housing temperature(23±5)℃，the relative humidity is random,the supply voltage for rated measuring voltage ±5, the effective distance measuring the resulting amount of change in the range of 8 hours.

The switching frequency is the maximum times of sensor operation per second.

IP PROTECTION CLASS SYSTEM was drafted by IEC (International Electrotechnical Commission).Classify electrical appliances according to their dust and moisture resistance characteristics. The external objects referred to here, including tools, and human fingers, should not come into contact with the live parts inside the electrical appliance to avoid electric shock. The IP protection level is composed of two numbers. The first number represents the level of dust separation and prevention of foreign object intrusion of the product, the second number represents the degree of airtightness of the product against moisture and water intrusion, and the larger the number, the higher the protection level.

The emitter of the photoelectric sensors typically use the following light sources: Red LED-visible, can be easily adjusted. Infrared LED-high-energy unvisivle light. Red laser-visible light, its physical characteristics are the ideal choice for small detected body and a wide range of detection. The Vanguard IFM brand photoelectric sensor using infrared LED as a light source.

The load current is in the normal case, the working current through the sensor.

When the sensor is not turned on, the residual current in its load, is called leakage current.