Q：Inductive sensors？

A：Inductive sensors are the principle of mutual inductance using metal conductors and alternating electromagnetic fields. The detecting coil at the front end of the sensor generates a high-frequency magnetic field, when the metal object approaches the magnetic field, an eddy current is generated inside of the metal object, causing the magnetic field energy to decay. When the metal object is continuously close to the sensing surface of the sensor, the energy is absorbed to cause attenuation, and when the attenuation reaches to a certain extent, the sensor switch output signal is triggered to achieve the non-contact detection purpose.    

Q：Inspection method of inductive sensor？

A：Inductive proximity switch belongs to non-contact switch (i.e, the switch sensor). It is generally used in mechanical automatic control equipment with high precision, long service life, fast response and convenient installation. It is mainly used as limit, reset, and stroke positioning, counting, automatic protection, replacement of micro switches and so on. The detector of inductive sensor must be a metal object and for non-metallic objects, the inductive switch has no action. It has the characteristics of waterproof, shockproof, oil proof, dustproof and corrosion resistant, and has strong applicability to harsh environment. 

Q：What is the error range of proximity switch sensing distance?

A：The error between the sensor's sensing distance and the standard sensing distance is typically ±10%.

Q：Output signal of inductive sensor？

A：Proximity switch is a general term for contactless sensors. It includes inductive, capacitive and Hall-type sensor. The output signal of inductive proximity switch is mainly: the on/off switch signal (ie, there is a metal object at any position within the maximum range detected by the proximity sensor of the proximity switch to the product, it will give a switching signal, when the object is out of the detection distance range, the sensor switching signal is opposite to the action).

Q：Operating voltage of inductive sensor？

A：The output of inductive proximity switches is generally divided into below 2 types: DC output DC12~24V（Max10~30V）, 2 wires, 3 wires, 4 wires, aviation plug, low voltage DC5~12V can also be customized. AC output AC220V（Max：10~250V), 2 wires.

Q：Can Defuro Inductive sensors detect magnets?

 A：Our proximity switches are not Hall-type and cannot detect magnets. But if the magnets are made of magnetic metal, they can be detected as ordinary magnetic metals.  

Q：Capacitive sensors？

A：The sensing surface of capacitive sensor is composed of two coaxial metal electrodes, which form a capacitor connected in series in the RC oscillation circuit. When the power is turned on, the RC oscillator does not oscillate. When a target approaches the sensor sensing surface, the capacitance increases and the oscillator begins to oscillate. It is converted into a switching signal by the processing of the latter stage circuit, thereby detecting the presence or absence of an object. Capacitive sensors can detect metal objects and non-metallic objects, the maximum working distance can be obtained for metal objects and the working distance of non-metallic objects depends on the dielectric constant of the material. The larger the dielectric constant of the material, the longer the action distance we can obtain.    

Q：Photoelectric sensor？

A：Photoelectric sensor is a general term for sensors that use light to detect objects. It's a device that emits an optical signal and the signal is reflected, blocked, and absorbed by the detected object, and then received by the receiving portion and converted into a corresponding electrical signal to achieve control. Photoelectric sensors are generally composed of three parts: transmitter, receiver and detection circuit.  

Q：How to estimate the standard detector of photoelectric sensor?

 A：The standard detector of through-beam sensor and retro-reflective sensor is an opaque object, the diameter is the bigger one of  diagonal length. Generally the standard detector length of through beam sensor is the diagonal length of the emitter and receiver. The retro reflective sensor considers the diagonal length of the reflector as the diameter of standard detector.   The standard detector of diffuse reflection sensor is a white paper whose size is the same with diameter of the projection beam.  

Q：What is the frequency of photoelectric sensor?

A：When converting the frequency, we need to find the product information to understand the response time of the product, as shown in the following figure: The response time of HLD through beam sensor (sensing distance 5m) is 2ms, this 2ms represents vibration and reset for 2ms, so the whole response time is 4ms.  Then the frequency f=1/(2* response time), which is 250Hz.

Q：Characteristics of photoelectric sensor?

A：Non-contact detection, with long service life and no damage to the detected object Suitable for long distance testing, wide range of applications Suitable for various detected objects, and objects that affect light propagation are also applicable. High response frequency, suitable for high-speed production line detection. High detection accuracy, suitable for distinguishing different colors.  

Q：What kinds of light sources are commonly used in photoelectric sensors?

A：The emitter of photoelectric sensor typically use the following types of light sources: Red LED--Visible light, easy to adjust Infrared LED-- High energy invisible light Red laser-- Visible light, it's ideal for small object detection and a wide range of detection ranges. Defuro photoelectric series sensors mainly use infrared LEDS as light sources.