自制光谱仪实时测量溶液浓度

Real Time Measurement of Solution Concentration Based on Double Beam Optical Path

浓度是表征溶液特征的物理量,其测量在生物医学、材料科学等领域具有重要的研究意义。本文利用自制简易光栅光谱仪搭建了溶液浓度实时测量系统。光路采用双光束有利于减小吸收光谱的抖动,从而提高测量系统的稳定性;简易光谱仪结合机器视觉技术实现对浓度在线测量的功能。由朗伯-比尔定律建立吸光度A-浓度c的工作曲线,自主设计程序实时测量待测样品的吸收光谱得到吸光度,并根据工作曲线测量样品的浓度。由该装置测量得到高锰酸钾溶液浓度的相对误差在1%以内,表明该测量系统能够快速、精确地测量溶液浓度。

Concentration is a physical quantity characterizing the characteristics of solution.Its measurement has important research significance in biomedicine,material science and other fields.A real-time measurement system of solution concentration is built by using a self-made simple grating spectrometer.The use of double beams in the optical path is conducive to reduce the jitter of the absorption spectrum and improve the stability of the measurement system.The simple spectrometer combined with machine vision technology realizes the function of on-line concentration measurement.The working curve of absorbance a-concentration C is established by Lambert Beer law.The self-designed program measures the absorption spectrum of the sample to be measured in real time to obtain the absorbance,and measures the concentration of the sample according to the working curve.The relative error of potassium permanganate solution concentration measured by the device is less than 1%,which shows that the measurement system can measure the solution concentration quickly and accurately.