Note: This chart is used when (2 ≤ Number of Trials ≤ 10)
The difference between the largest and smallest trial for each part for each Appraiser.
The Average Range for the parts from each Appraiser (i.e. a different Center Line is calculated for each Appraiser).
UCL , LCL (Upper and Lower Control Limit)
Separate Control Limits are calculated for each Appraiser:
R-baroper is the Center Line (above)
d3 is based on subgroup size equal to the number of trials
d2* is based on a subgroup size m = the number of trials and number of samples g = the number of parts.
2. Table for d2* values may be found in A.J. Duncan, Quality Control and Industrial Statistics, 1965, Third Edition Richard D. Irwin, Homewood, Illinois. Table D3, pg. 910.
Repeatability Range Chart Calculations: Combined Appraisers (If (2 ≤ Number of Trials ≤ 10)
Repeatability Sigma Chart Calculations: Combined Appraisers (If (Number of Trials > 10)
Repeatability Sigma Chart Calculations: Per Appraiser (If (Number of Trials > 10)