Residual Value Test of Determination Calibration Curve of Total Nitrogen in Water Based on Mathematical Statistics Method
Objective Exploring the normality,independence,and homoscedasticity of residual values in the determination calibration curve of total nitrogen in water.Methods Six measurements of nitrate nitrogen standard solutions with different concentrations were conducted within a year,and the calibration curve was fitted using the measurement results to calculate the residual value.Test the normality of residual values through QQ diagrams and Anderson Darling(AD)method;Test the independence of residual values through graphical and DW methods;Test the homoscedasticity of residual values through Residual Plots and Rank Correlation Coefficient methods.Results The residual value of this sam-ple satisfies normality,but does not satisfy independence and homoscedasticity.Conclusion The curve fitting of data using Ordinary Least Squares method needs to be based on a series of assumptions.In actual work,we cannot blindly default the establishment of relevant assump-tions,and should combine mathematical statistics theory with laboratory testing to ensure the reliability of curve fitting.
国家科技期刊平台
NSTL
万方数据
维普
