G 归东龙子大写 Analytical Chemistry The middle numerical value in a set of values. 4.Accuracy Accuracy describes the nearness of an experimental value to the true value. Accuracy is expressed as error E=x-m relative error (RE)is calculated by the following formula:
Analytical Chemistry 4. Accuracy Accuracy is expressed as error relative error (RE) is calculated by the following formula: The middle numerical value in a set of values. Accuracy describes the nearness of an experimental value to the true value. 2023/7/28 6
归东理工大军 Analytical Chemistry E RE= '100% m 5.Precision precision refers to the agreement between values in a set of date,it describes the reproducibility of measurements. (1)Deviation d;=xi-x
Analytical Chemistry 5. Precision precision refers to the agreement between values in a set of date, it describes the reproducibility of measurements. (1) Deviation 2023/7/28 7
G 归东我王大 Analytical Chemistry (2) Relative deviation RD=4100% X (3)average deviation ax;-x d i=l n
Analytical Chemistry (2) Relative deviation (3) average deviation 2023/7/28 8
归东我工大军 Analytical Chemistry (4) standard deviation a (x-x)》 i=1 n-1 6.The relationship between accuracy and precision Error and deviation,the respective measures of accuracy and precision,are not always numerically related to one another
Analytical Chemistry (4) standard deviation 6. The relationship between accuracy and precision Error and deviation, the respective measures of accuracy and precision, are not always numerically related to one another. 2023/7/28 9
归东理工大图 Analytical Chemistry That is,the precision of the data in a set can be excellent while the overall accuracy is terrible. The precision must be good if we want to get a high accuracy
Analytical Chemistry That is, the precision of the data in a set can be excellent while the overall accuracy is terrible. The precision must be good if we want to get a high accuracy. 2023/7/28 10