A photoelectric liquid level measuring device

Abstract

The invention discloses a photoelectric liquid level measurement device, and belongs to the technical field of photoelectric detection. A light guide plate is used for being in face contact with or being adjacent to liquid to be subjected to liquid-level measurement, is a solid integrity, and is pervious to light, a light guide plate liquid level face and a light guide plate lighting face are arranged on the light guide plate, and the light guide plate liquid level face is used for being in face contact with or being adjacent to the liquid to be subjected to liquid-level measurement; the liquid level line of the to-be-measured liquid falls into the light guide plate liquid level face, a light guide microstructure is arranged at the light guide plate lighting face and used for guiding lighttransmitted in the light guide plate out of the light guide plate, light beams are emitted into the light guide plate from positions except the light guide plate liquid level face and the light guideplate lighting face, through the liquid level of the to-be-measured liquid, the transmission of the light beams in the light guide plate is changed, and thus a light field of emergent light of the light guide plate lighting face is changed; by detecting the change of the light field of the emergent light, the liquid level of the to-be-measured liquid is detected. The measurement device is simplein structure, components and parts are low in price, the measurement is precise and reliable, and maintenance is convenient.

Description

technical field [0001] The invention belongs to the technical field of photoelectric detection, and in particular relates to a photoelectric liquid level measurement method and device with high precision and strong anti-interference performance. Background technique [0002] Liquid level measurement is widely used in the fields of biology, chemical processing and preparation, and fuel monitoring. The existing liquid level measurement systems mainly include capacitive, ultrasonic and optical fiber types according to their principles. [0003] The basic principle of the capacitive liquid level measurement system is: the filling liquid between the two electrodes of the capacitor will cause the capacitance to change, and the liquid level can be obtained by measuring the capacitance of the capacitor immersed in the liquid. The application of capacitive liquid level measurement has great limitations. There are disadvantages such as the measurement is susceptible to electromagnetic...

AI Technical Summary

Problems solved by technology

The application of capacitive liquid level measurement has great limitations. There are disadvantages such as the measurement is susceptible to electromagnetic interference, the capacitor must be immersed in the liquid for measurement, the measuring device is easily corroded, and it cannot measure flammable and explosive liquids.

[0004] Ultrasonic liquid level measurement uses the ultrasonic sensor to detect the transmission time of the reflected echo on the liquid surface to measure the liquid level. Due to the fast propagation speed of sound waves and the presence of other reflected echoes besides the liquid surface, ultrasonic liquid level measurement is difficult to achieve High precision and stable liquid level measurement

And the speed of sound is affected by factors such as density, pressure, temperature, etc., and cannot adapt to changing environments

[0005] In recent years, with the rapid development of optical fiber sensors, the application of optical fibers in the field of liquid level measurement has become more and more popular. Optical fiber liquid level measurement detects liquid levels by changing the effective refractive index of special optical fibers when immersed in liquids. For example, using various The change of the effective refractive index of the optical fiber grating in the liquid leads to the shift of the central wavelength of the optical fiber grating to measure the liquid level. Although the optical fiber liquid level measurement has certain advantages compared with the previous liquid level measurement method, such as measuring flammable and explosive liquids, anti-electromagnetic interference, but there are still some disadvantages, such as must be immersed in liquid measurement, it is difficult to adapt to liquids with different refractive indices, the need for a spectrometer leads to higher costs, and it is inconvenient to maintain, etc.

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