RGB颜色模式下的水溶液pH值定量测定

Quantitative Determination of Water Solution pH under RGB Colour Mode

在手机比色法基础上,引入误差传递规律,提出了一种测量pH值的新方法。在石蕊指示剂的显色范围内,向系列标准pH缓冲溶液滴加石蕊,溶液颜色由红变紫,以3款不同类型手机进行图片采集,利用误差传递公式对直接测量值进行优化。结果表明,理论和实验均证明了改进后的手机比色法的误差更小。3款手机得到的间接测量值与pH值变化趋势一致,其中iPhone 5S的X B与pH值线性关系最优。2组平行实验测定的相对标准偏差分别为2.009%和6.546%。以pH酸度计为测定标准,用该方法对自来水、农夫山泉天然水、百岁山矿泉水和爱夸矿泉水进行测定,两者的pH值测定结果基本一致,表明pH手机比色法的稳定性和可靠性符合测定要求。

On the basis of mobile phone colorimetry,a new method for measuring pH value had been proposed by introducing error transfer law.Within the colour range of litmus indicator,litmus was dropped into a series of standard pH buffer solutions,and the solution colour changed from red to purple.Picture collection was carried out with 3 mobile phones of different types,and the direct measurement values were optimized by the error transfer formula.Experiments showed that both theory and experiment proved that the improved mobile phone colorimetric error was smaller.The indirect values obtained by three phones were consistent with pH change trend,among which the linear relationship between X B of iPhone 5S and pH was the best.The relative standard deviations of two sets of parallel experiments were 2.009% and 6.546%,respectively.Taking the pH meter as the determination standard,analyses were performed in acquired samples of tap water,Nongfu Spring natural water,Baisuishan mineral water and Aikua mineral water.The pH values of two methods were basically the same,indicating that the stability and reliability of the pH mobile phone colorimetry met the requirements of pH test.