Basically, the collimator diameter should match the sample size when performing measurements.
Cases in which the collimator size does not have to match the sample size:
• Performing qualitative analysis only (quantitation not needed)
• Samples with no balance components
(E.g.: Metals, glass, etc.)
• When quantifying with a calibration curve with internal standard correction set
(E.g.: RoHS analysis 10 mm dia. analysis)
Limited to uniform samples