Fiber optic sensors and photoelectric sensors are two typical types of sensors, and they are widely used in production measurement. So what are the differences between the two? Next, we will analyze the differences between the two from the aspects of principle and application.
I. Principles
A photoelectric sensor is a sensor that uses photoelectric elements as its detection element. It first converts the change in the measured quantity into a change in a light signal, and then, with the help of photoelectric elements, further converts the light signal into an electrical signal. A photoelectric sensor generally consists of three parts: a light source, an optical path, and photoelectric elements.
Fiber optic sensor: Light from a light source is sent through an optical fiber to a modulator, so that the parameter to be measured interacts with the light entering the modulation region, causing changes in the optical properties of the light (such as light intensity, wavelength, frequency, phase, polarization, etc.), which is called the modulated signal light. After passing through an optical fiber to a photodetector, the parameter to be measured is obtained after demodulation.
II. Applications
1. Application areas of photoelectric sensors:
Preventing industrial dust pollution is a crucial task in environmental protection. To eliminate industrial dust pollution, it's essential to know the amount of dust emitted; therefore, monitoring the dust source, automatic display, and alarm functions for exceeding limits are necessary. The turbidity of dust in the flue is detected by measuring the change in light intensity during its transmission within the flue. If the flue turbidity increases, the absorption and refraction of light emitted from the light source by dust particles increases, reducing the amount of light reaching the photodetector. Therefore, the strength of the photodetector's output signal reflects the change in flue turbidity.
Applications of photovoltaic cells in photoelectric detection and automatic control: When used as a photoelectric detector, the basic principle of a photovoltaic cell is the same as that of a photodiode, but their basic structure and manufacturing process are not exactly the same. Because photovoltaic cells do not require an external voltage to operate; they have high photoelectric conversion efficiency, a wide spectral range, good frequency characteristics, and low noise, they have been widely used in photoelectric readout, photoelectric coupling, grating ranging, laser collimation, movie sound reproduction, ultraviolet monitors, and flameout protection devices for gas turbines, etc.
2. Application areas of fiber optic sensors:
Measurement of physical quantities such as insulator contamination, magnetism, sound, pressure, temperature, acceleration, gyroscope, displacement, liquid level, torque, photoacoustic, current and strain.
The above explanation of the differences between fiber optic sensors and photoelectric sensors should hopefully be helpful to everyone.
