Difference between the average value for the measurement, corrected to make up for any known systematic measuring errors, and the upper and lower limit for the (measurement uncertainty) interval within which the correct result lies. As such, measurement uncertainty does not account for the entire breadth of this interval! (Figure M 22) (as per DIN 1319).
Figure M 16 shows these relationships based on the example of possible errors associated with a position measurement system.
Figure M 22: Upper and lower levels for measurement uncertainty