The bias statistics consist of:

·    Bias, how different the mean is from the reference value.

·    T, which is the T statistic for testing the null hypothesis that Bias = 0.

·    P-value, which is the probability (|T|>t) where T follows the t-distribution with n-1 degrees of freedom, where n is the number of measurements.

These values indicate whether you have significant bias in your measurements.

For the thickness data, the p-value is 0.021, which indicates that the null hypothesis for the test of bias=0 must be rejected.

There is significant bias present in the measurement system, even though the value seems small (-0.000015).