Liquid density on-line monitoring system based on ultrasonic diffraction grating

Abstract

The invention provides a liquid density on-line monitoring system based on ultrasonic diffraction grating, which comprises a laser, a beam expander, a collimator, a piezoelectric ceramic plane ultra radiation wave generator, a direct digital synthesizer (DDS) ultrasonic signal source, an ultrasonic pool, a peristaltic pump sample introduction system and a charge coupled device (CCD) monitoring system. A high-quality monochromatic line light source can be obtained after laser beams output by the laser pass through the beam expander and the collimator, and high frequency sine and cosine signalsgenerated by the DDS ultrasonic signal source stimulate the piezoelectric ceramic plane ultra radiation wave generator to form 'the ultrasonic grating' in the ultrasonic pool. Emergent laser beams ofthe line light source become a row of extremely fine monochromatic diffraction stripes through the diffraction of 'the ultrasonic grating', a converging lens converges emergent rays of same-directiondiffraction angles on the photosensitive surface of the CCD monitoring system. Diffraction strips are collected by the CCD monitoring system into computers, and the space between strips and the density of liquid samples are calculated. The liquid density on-line monitoring system has the advantages of being high in precision, easy to measure in real time, simple and compact in structure, high in operability, free of complicated optical systems, low in cost and the like.

Description

technical field [0001] The invention relates to an on-line monitoring system for liquid density, in particular to an on-line monitoring system for liquid density based on an ultrasonic diffraction grating. Background technique [0002] At present, photoelectric technology and ultrasonic technology are quite mature, and they are widely used in many fields. For the on-line monitoring of liquid density, there is no instrument and equipment in China that combines photoelectric and ultrasonic technology to monitor liquid density. For the determination and monitoring of liquid density, the following two measurement methods are mainly used: [0003] (1) In the case of a fixed volume, its density is obtained by monitoring the corresponding mass; [0004] (2) Use the force sensor to measure the pressure difference in the liquid. [0005] The main disadvantages of these two methods are: [0006] (1) There are strict requirements on the working state of the sensor. To achieve accur...

AI Technical Summary

Problems solved by technology

[0008] (3) Fatigue changes in the characteristic curve of the sensor, such as the quality of the characteristic curve of the sensor decreases with the passage of time, resulting in a decrease in accuracy and an increase in error

Images