Factures that are important for getting good data. Agreement between laboratories using high volume instrument (HVI) systems to test Cotton include using the correct calibration cottons, proper use of those calibration cottons, and good calibration procedures. It is also important to property condition the samples before testing and to carefully maintain the laboratory relative humidity during testing. Even with proper lab conditions, sample conditioning and instrument calibration, there are limits to the lab-to-lab agreement that are controlled by the with-in-sample variability and the number of tests made per bale or sample.