German ALPAR METAL sensor ALPAR METAL model ALPAR METAL price

ALPAR METAL sensors are sensors that use laser technology for measurement. They consist of a laser, a laser detector, and a measurement circuit. Laser sensors are a new type of measuring instrument; their advantages include the ability to perform non-contact long-distance measurement, high speed, high precision, large measuring range, and strong resistance to optical and electrical interference.

ALPAR METAL sensor detection principle

Detection is achieved by influencing with an external magnetic field to detect magnetic losses caused by eddy currents generated on the surface of a conductor. An AC magnetic field is generated within the detection coil, and detection is performed by monitoring impedance changes caused by eddy currents in the metallic target body. Additionally, other methods include aluminum detection sensors that detect frequency phase components, and all-metal sensors that detect only impedance change components via the working coil. A transformer-like state occurs between the surface of the target object and the surface of the sensor.

ALPAR METAL sensor classification

1) Capacitive proximity sensor: This is a capacitive proximity switch with an electrode as the detection terminal. It consists of a high-frequency oscillation circuit, a detection circuit, an amplification circuit, a shaping circuit, and an output circuit. Normally, there is a certain capacitance between the detection electrode and ground, which forms part of the oscillation circuit. When the detected object approaches the detection electrode, the voltage applied to the electrode causes electrostatic induction and polarization. The closer the object gets to the detection electrode, the more induced charge accumulates on the electrode. Since the electrostatic capacitance of the detection electrode is C, the capacitance C increases as the charge increases. Because the oscillation frequency of the oscillation circuit is inversely proportional to the capacitance, an increase in capacitance C weakens the oscillation, potentially stopping it entirely. These two states—oscillation and non-oscillation—are converted into switch signals by the detection circuit and output externally. 2) Inductive proximity sensor: Consists of a high-frequency oscillation circuit, a detection circuit, an amplification circuit, a shaping circuit, and an output circuit. The sensitive element for detection is the detection coil, which is part of the oscillation circuit. The oscillation frequency of the circuit is L. When AC current flows through the detection coil, an alternating magnetic field is generated around it. When a metal object approaches the detection coil, eddy currents are induced in the metal object, absorbing magnetic energy. This causes the inductance L of the detection coil to change, reducing the oscillation frequency of the circuit until oscillation stops. These two states—oscillation and non-oscillation—are converted into switch signals by the monitoring circuit and output. Note: Similar to capacitive proximity sensors, inductive proximity sensors detect metallic conductors; non-metallic conductors cannot be measured using this method. Amplitude variations differ depending on the type of metal in the target object, so the detection distance also varies with the metal type. 3) Photoelectric proximity sensor: The beam axis of the light-emitting diode (or semiconductor laser tube) and the axis of the phototransistor lie in the same plane and form a specific angle, intersecting at a point in front of the sensor. When the surface of the detected object approaches this intersection point, reflected light from the LED is received by the phototransistor, generating an electrical signal. When the object moves away from the intersection, the reflection area falls outside the phototransistor's field of view, and the detection circuit produces no output. Generally, the drive current supplied to the LED is not DC but AC at a specific frequency. Consequently, the receiving circuit also receives an AC signal of the same frequency. Filtering the received signal to allow only signals of this frequency to pass effectively prevents interference from other ambient light and can increase the LED's luminous intensity.

ALPAR METAL sensor applications

Proximity sensors are primarily used to detect object displacement and are widely applied in aviation, aerospace technology, and industrial production. In daily life, they are used in automatic doors and automatic heaters in hotels, restaurants, and garages. For security and anti-theft purposes, important locations such as archives, accounting departments, financial institutions, museums, and vaults are typically equipped with anti-theft devices composed of various proximity switches. In measurement technology, they are used for length and position measurements; in control technology, they are extensively used for measuring and controlling displacement, speed, and acceleration.

Weidou Intelligent Technology specializes in selling German ALPAR METAL sensors, ALPAR METAL proximity sensors, ALPAR METAL distance sensors, ALPAR METAL vision sensors, ALPAR METAL displacement sensors, ALPAR METAL torque sensors, ALPAR METAL speed sensors, ALPAR METAL photoelectric sensors, ALPAR METAL position sensors, ALPAR METAL angle sensors, ALPAR METAL tactile sensors, ALPAR METAL temperature sensors, ALPAR METAL pressure sensors, ALPAR METAL flow sensors, ALPAR METAL level sensors, ALPAR METAL motion sensors, and ALPAR METAL process sensors. All products are original imports from Germany. Customers are welcome to inquire and place orders.