Photoelectric sensors have several measurement methods, based on the principle of measurement is what?

Photoelectric sensors have four measurement methods, based on the principle of measurement is through the change of light intensity into the change of electrical signals to realize the control.

Introduction of photoelectric sensors:

Photoelectric sensors are 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 irradiated on certain substances, the material electrons absorb the energy of photons and the corresponding electrical effect phenomenon. According to the photoelectric effect phenomenon will be divided into three categories of photoelectric effect: external photoelectric effect, internal photoelectric effect and photovoltaic effect.

Measurement:

1, slot photoelectric sensor. A light emitter and a receiver face-to-face in a slot on both sides of the composition of the slot photoelectric. The emitter can emit infrared light or visible light, and the light receiver can receive light in the absence of resistance.

2, reflector type photoelectric switch. The light emitter and light receiver into the same device, installed in front of a reflector, the use of the principle of reflection to complete the role of photoelectric control, known as the reflector reflective photoelectric switch.

3, diffuse reflection photoelectric switch. Diffuse reflective photoelectric switch detection head is also equipped with a luminescence and a light collector, but the diffuse reflective photoelectric switch in front of no reflector. Under normal circumstances the light emitted by the emitter is not found in the light receiver.

4, the counter-reflective photoelectric sensor. If the light emitter and light receiver separated, it can make the detection distance increased, a light emitter and a light receiver composed of a pair of separate photoelectric switch, referred to as the counter-emitting photoelectric switch.

Photoelectric sensor applications:

1, soot turbidity monitor

Preventing industrial soot pollution is one of the important tasks of environmental protection. In order to eliminate industrial soot pollution, the first thing to know the soot emissions, so the soot source must be monitored, automatic display and exceed the alarm. The turbidity of the soot in the flue is detected with the size of the change in the transmission process through the light in the flue.

2, bar code scanning pen

When the scanning pen head in the bar code on the movement, if encountered black lines, light-emitting diode light will be absorbed by the black line, the photosensitive transistor can not receive the reflected light, high impedance, in the cut-off state. When encountering white intervals, the light emitted by the light-emitting diode, is reflected to the base of the photosensitive transistor, the photosensitive transistor generates photocurrent and conduction.

3, product counter

Products running on the conveyor belt, constantly blocking the light source to the photoelectric sensor of the optical path, so that the photoelectric pulse circuit produces an electrical pulse signal. Every time the product shades the light, the photoelectric sensor circuit produces a pulse signal, therefore, the number of output pulses that represents the number of products, the pulse counted by the counting circuit and displayed by the display circuit.