Apparatus and method are provided for loading a cell for testing crush-resistance of a proppant or other granular material. The apparatus includes a rod valve and one or two screens selected to allow proppant to pluviate into the cell. Stress may be applied to the cell and the amount of proppant crushed by the stress may be measured. Measurements may be repeated to produce mean and variance values. Screen sizes may be varied to select sizes to minimize variance of measurements.