利用近红外吸收光谱特性实现酒精浓度的非接触式测量系统的设计  

Design of non-contact measurement system for ethanol concentration using near infrared spectrometry characteristics

作　　者：王添 吴卫 张紫芸馨 Wang Tian;Wu Wei;Zhang Ziyunxin(School of Physics and Electronic Science,Guizhou Education University,Guiyang 550018,Chi)

机构地区：[1]贵州师范学院物理与电子科学学院,贵州贵阳550018

出　　处：《红外与激光工程》2023年第12期166-172,共7页Infrared and Laser Engineering

基　　金：中央引导地方科技发展专项资金项目(黔科中引地[2019]4012号)。

摘　　要：酒精浓度的非接触式测量是一种新型的测量方法。对一些特殊行业有着很大的帮助,比如酿酒业测量酒的酒精浓度,工业上生产工业酒精等。为了便于测量不能接触的酒精溶液,文中设计了一种基于近红外吸收光谱特性的酒精浓度测量系统,可以对不同浓度的酒精溶液进行非接触式连续测量。对于酒精来说,在1300~1350 nm的光谱段浓度定性反应非常明显,使用处于该波段的红外LED发光二极管,加上光电二极管、模数转换芯片、单片机和LCD屏幕组成该系统。通过使用该系统对不同浓度的酒精进行测量,利用最小二乘法找到酒精浓度和电压信号之间的函数关系式。这样就能通过测量电压值来反推出酒精浓度值。实验表明,在该红外波段下,采集到的电压值和酒精浓度之间有良好的二次函数关系,拟合优度达到了0.99946。测量结果显示,测量值和标准值之间的相关系数R为0.999911,平均绝对误差为0.64。与传统酒精计的0.5相差不大,重复测量和连续测量的方差分别为0.0044和0.0056,证明了该装置的稳定性和可靠性符合预期。而且通过优化电路和程序,选择更为精确的酒精计作为标准,可以使误差更小。该方案相比传统测量方法结构简单,速度更快,还可以进行连续测量。在现实生活中,制酒业、医疗行业和工业生产等行业都对于测量酒精浓度有着很高的需求。该装置可以在不损坏产品的情况下进行酒精浓度测量,它的连续检测能力对某些行业的批量生产有着很大的帮助。通过改良,可以实现自动化检测。除了企业生产,也可用于制造日常使用的便携式酒精浓度测量仪。Objective The non-contact measurement of ethanol concentration represents a novel approach to concentration measurement,offering significant advantages for specialized industries such as medical,wine,and industrial alcohol.To facilitate non-contact ethanol measurement,a dedicated ethanol concentration measurement system has been designed based on the characteristics of infrared spectrometry.This system enables continuous and contactless measurement of varying concentrations of ethanol.Methods In the context of ethanol,the spectral characteristic response is highly sensitive in the 1,300-1,350 nm range of the near-infrared band.Therefore,an infrared LED light-emitting diode emitting in this band is employed as the light source,and a photodiode sensitive to this band is chosen as the receiver.When exposed to light,the photodiode generates a weak reverse current,which is then converted into a voltage signal by the transimpedance amplifier.Subsequently,an A/D converter chip is utilized to collect the voltage signal.Using this system,the relationship between ethanol concentration and the voltage signal can be determined by measuring different concentrations of ethanol.Consequently,the ethanol concentration value can be obtained by measuring the corresponding voltage value.Results and Discussions The experiment demonstrates a robust quadratic function relationship between the voltage and ethanol concentration in the infrared band.The results reveal a high correlation coefficient of 0.99911,with an average absolute error of 0.64.This level of error is comparable to that of traditional ethanol measurement devices(0.5),affirming the feasibility of the device.Further optimization of the circuit and program has the potential to reduce errors.Compared to traditional measurement methods,this approach boasts advantages such as a simple structure,faster operation,and the capability for continuous measurement.Conclusions The device designed for measuring ethanol concentration holds significant value in various industries such as

关 键 词：酒精浓度测量 近红外吸收光谱特性 非接触测量 光电二极管 红外LED光源 

分 类 号：TN216[电子电信—物理电子学]