Indentation hardness test, performed with either 3 gf or 9 gf loads, preceded the development of microhardness testers using traditional indenters. In 1925, Smith and Sandland of the UK developed an indentation test that employed a square-based pyramidal indenter made from diamond. They chose the pyramidal shape with an angle of 136° between opposite faces in order to obtain hardness numbers that would be as close as possible to Brinell hardness numbers for the specimen. The Vickers test has a great advantage of using one hardness scale to test all materials.The first reference to the Vickers indenter with low loads was made
Worshipful Company of Scientific Instrument Makers or using scientific instruments. This could be any kind of scientific instrument: a measuring instrument, like a feeler gauge or an atomic clock, or an imaging instrument like a PET scanner. It might even be a piece of control engineering incorporating many instruments. What makes the Company a community is partly a shared interest in scientific instruments and, more generally, in science and engineering. It is also partly a shared love of good company, of meeting for discussion over food and wine, and of bringing partners or guests to a grand banquet in distinguished surroundings. But what makes the Company