Photometry Under the Condition of "Precision Rule"

Abstract

Taking the determination of manganese in iron and steel as an example, it is proved that following the "precision rule", that is, “to maintain infection consistency of each factor for the each sample in the same measurement series”, the "content determination series" of photometry will present its "content absorption law": In the absorbance domain ,the coordinate points of all content and corresponding absorbance must be in the same straight line. Whether it's trace or high content, the connecting line of the coordinate points of the upper and lower limits of the two standard samples can be used as the "measuring line" of the sample content. The "two standard photometry" is established, which changes the traditional concept and presents the simple, high-speed and high efficiency nature of photometry. It is also the embodiment of normal distribution theory in photometry, so the measured values of samples are normal distribution. Systematic error and abnormal error (statistical outlier) are easy to find, which ensures the reliability of the measurement results. The uncertainty evaluation of the measurement results is simplified, the measurement model of the uncertainty is established, which is concise and practical, and realizes the unity with the allowable error; The new understanding also provides new ideas for the development of photometer: The measuring parts of the photometer shall conform to the "precision rule"; The filter beam has higher sensitivity and better reproducibility.