分光光度法测定地表水叶绿素a的测量不确定度分析

Measurement Uncertainty Analysis of Chlorophyll-a in Surface Water by Spectrophotometry

采用分光光度法对地表水中叶绿素a进行了不确定度评定,发现影响地表水叶绿素a测量不确定度的因素包括样品体积、定容体积、测量重复性、比色皿光程、分光光度计透射比最大允差等。按照测量不确定度的传播规律建立数学模式进行了分析,结果表明:当水中叶绿素a的检测结果为2.40mg/m^3时,取包含因子k=2,扩展不确定度为0.16mg/m^3。

The uncertainty of chlorophyll a in surface water was determined by spectrophotometry.The factors affecting the measurement uncertainty of surface water chlorophyll a include sample volume,constant volume,measurement repeatability,cuvette optical path,and the maximum tolerance of the spectrophotometer transmittance.The mathematical model is established according to the propagation law of measurement uncertainty.The results show that:when chlorophyll a in water was detected as 2.40 mg/m^3,include factor k=2,extension uncertainty is 0.16 mg/m^3.