Gage R&R Procedures: Selecting parts (sample) to measure
I am fairly new to Gage R&R studies, and I need to perform one on an analytical balance used mainly to weigh tablets. There are about 5 different kinds of tablets that are normally weighed in this balance (different sizes and weights). I understand that for the study I should select tablets that are representative of the usual variation, which i interpret means that if a tablet's target weight is 0.1g but varies from 0.096 to 0.15, i should pick tablets that cover that range. My confusion is, should i pick one type of tablet and select 25 (or however many is necessary) samples of the same tablet, ensuring that they cover that range, or should i pick tablets from the five different kinds?
Thank you for your help!