This practice is applicable for qualitatively evaluating coated and uncoated monolithic polycarbonate sheet material, for monitoring process control, for screening studies, and as an aid in the prediction of hardware performance when exposed to impact service conditions.

A limitation of Type A specimen testing is that a thick sheet may not fail since the available impact energy is limited by the maximum drop height and falling weight capacity of the test apparatus. Use Specimen Type A for material less than 12.7 mm (0.50 in.) thick.

Within the range of drop heights of this system, tests employing different velocities are not expected to produce different results. However, for a given series of tests, it is recommended that the drop height be held approximately constant so that velocity of impact (strain rate) will not be a variable.

As the polycarbonate specimen undergoes large plastic deformation under impact, the down (opposite impact) side is under tensile loading and most influential in initiating failure. Polycarbonate sheet coated on one side may yield significantly different test results when tested with the coated side down versus the coated side up.

Direct comparison of specimen Type A and specimen Type B test results should not be attempted. For test programs that will require the comparison of interlaboratory test results the specimen type and the approximate drop height must be specified.

Monolithic polycarbonate sheet is notch sensitive. Data obtained from other test methods, particularly notched Izod/Charpy test results, and extremely high- or low-strain rate test results, should not be compared directly to data obtained from this method. It is noted that Type A specimens, free of flaws, have not experienced the characteristic ductile-to-brittle transition between thin, less than 3.18 mm (¹/₈ in.), and thick, greater than 7.94 mm (⁵/₁₆ in.), sheet as reflected by other test methods.