The purpose of Drop Test is to simulate two situations: one is improper handling of packages during shipping and transportation, and the other is accidental dropping of unpackaged hand held products. Usually the drop height is based on the weight and the drop probability. However, for the same weight, there is a variance of specified height in different international standards.
Most predetermined drop heights for hand held products (eg: cell phones, MP3, etc.) are between 100cm~150cm. In IEC standards, hand held products≦2 kg are recommended a drop height of 100 cm without being damaged. In MIL standards, the drop height is 122 cm. Intel recommends the drop height to be 150 cm.
For the drop probability, in 1979, Americans researched the relationship between drop probability and the weight of the product and they found out:
Most products are easily dropped at a lower height in most times; in contrast, fewer drops are from a higher height.
Unitized loads are usually dropped less and have less drop probability than a single unit.
Most packaging is dropped on the bottom face and the statistics show that during shipping and handling, the number of drops and drop probability on the bottom face is over 50%; therefore, packaging design must consider protection of the bottom face.
From these findings, we know that in the theory of drop testing, the drop height is mostly based on the drop probability of the product (see Figure 2). According to the findings of packaged drop probability, if we wish the product to have 1% damage, the designed height should be 81cm (32inch). If we wish to have 4% damage, then the height should be 50cm (20inch). In other words, if we strictly requested damage probability to be under 1%, the packaged drop height should be 106cm (42inch). This type of evaluation is to find the greatest balance between the cost of product's damages and the cost of transportation.