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Estimation of Repeatability by Double Measured Data

Repeatability is estimated by calculating standard deviation using repeated measured data.

But there is the case that we want to know repeatability without such data. It is the case that repeating is difficult. In this case Measured data is useful.

Difference between Errors of Samples and Repeatability

For example, there is a data set of 5 samples measured by A and B. And that of standard deviation.
Double Measured Data

Standard deviation 2.1 for A and 2.2 for B are sums of errors of samples and repeatability.
Double Measured Data

Division of Errors of Samples and Repeatability

Double Measured Data
Then difference of repeatability A and B is calculated.
Double Measured Data(1)

Calculate the difference of A and B. Then calculate standard deviation of this difference.
Double Measured Data

Meaning this standard deviation is below.
Double Measured Data (2)

At this point we can see the goal. We can get the value of repeatability using the upper formlations (1) and (2).
Double Measured Data

NEXT Use Double Measured Data for Pattern Recognition