Barcol hardness test the Barcol impressor was developed by Walter Colman as a hand-held, portable means of assessing the hardness of a material during World War II. The United States Army Air Corps required a hand-held method of checking the hardness of rivets due to concerns that aircraft could be sabotaged by replacing normal rivets with soft lead or wooden ones which would fail during flight. The impressor operates when the tip is pressed against the material in question. The hardness of the material determines how far the tip indents and this is transferred by a tension spring and lever to be read
Leeb rebound hardness test was named “Equotip”, a phrase which still is used synonymously with “Leeb rebound” due to the wide circulation of the “Equotip” product. Traditional hardness measurements, "e.g.", those of Rockwell, Vickers, and Brinell, are stationary, requiring fixed workstations in segregated testing areas or laboratories. Most of the time, these methods are selective, involving destructive tests on samples. From individual results, these tests draw statistical conclusions for entire batches. The portability of Leeb testers can sometimes help to achieve higher testing rates without destruction of samples, which in turn simplifies processes and reduces cost. The traditional methods are based on well-defined physical