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 all parts from all selected Appraisers.
UCL , LCL (Upper and Lower Control Limit)
R-doublebar is the centerline of the Range Chart
Ordinate is the specified Sigma Level (usually 2.575 for Gage R&R analysis)
d3 is based on a subgroup size equal to the number of trials.
d2* is based on the sample size m = the number of trials and number of samples g = the number of Appraisers times 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 Sigma Chart Calculations: Combined Appraisers (If (Number of Trials > 10)
Repeatability Range Chart Calculations: Per Appraiser (If (2 ≤ Number of Trials ≤ 10)
Repeatability Sigma Chart Calculations: Per Appraiser (If (Number of Trials > 10)