Grubb test

  • To use the Grubb test, we initially calculate:
    • X: The average of the entirety of the measurements
    • S: The standard deviation of the entirety of the measurements

    G: Distance between the value suspected of being an abnormal point and the average  Grubb 1

 

Grubb 2

Next, we compare the G value that was found with a G limit:

Grubb 3

If G > Glimit then the value is considered abnormal and vice versa