There are two methods that are used to test the compressive strength of materials. These are as follows:
A. Manual strength testing method: It is usually done by placing a flat piece of material on a flat surface and then pressing the material using a flat rectangular metal plate called a stamp press. In the box compression tester, we use a hydraulic jack instead of a metal stamp press to compress the material. The results of this type of test are expressed in psi (pounds per square inch).
B. Automated strength testing method: The process of using an automated machine to do compression testing on boxes, cartons, and similar materials is Box Compression Tester also known as an automatic strength testing machine. This type of testing machine uses a device called a platen which is similar to the metal stamp used in manual strength testing method.
The main difference between the two types of test is the amount of pressure applied during the test.
In box compression test, two plates are placed on top of the boxes and they are compressed with the help of hydraulic jacks. Each of the hydraulic jack presses the two plates together.
The number of times that each of the two plates are pressed together is recorded. A standard procedure in box compression test is that when the maximum compression pressure is reached, a load cell measures the force applied to the two plates.