Some of the certificates of Quality testing are shown here.
The final product must meet certain specifications regarding physical and chemical properties. These properties are determined by standard tests established by the relevant institutions. Properties measured include mechanical strength, abrasion resistance, chemical resistance, water absorption, dimensional stability, frost resistance, and linear coefficient of thermal expansion. More recently, the slip resistance, which can be determined by measuring the coefficient of friction, has become a concern. However, no standard has yet been established because other factors (such as proper floor design and care) can make results meaningless.
We use statistical process control (SPC) for each step of the manufacturing process. Many also work closely with their raw material suppliers to ensure that specifications are met before the material is used. Statistical process control consists of charts that are used to monitor various processing parameters, such as particle size, milling time, drying temperature and time, compaction pressure, dimensions after pressing, density, firing temperature and time, and the like. These charts identify problems with equipment, out of spec conditions, and help to improve yields before the final product is finished.