During the 1980s, commercial electronic instrument manufacturers introduced many performance-oriented keyboard instruments that used digital computer technology in combination with built-in sound-synthesis algorithms.
Reflecting microscopes, in which the image is magnified through concave mirrors rather than convex lenses, were brought to their peak of perfection in 1947 by British physicist C.R. Burch, who made a series of giant instruments that used ultraviolet rays.
XPS instruments function in a manner analogous to SEM/EDS instruments that use a focused electron beam for compositional analysis.
By comparison, instruments that use beams of high-energy (10 keV to 10 MeV) electrons are relatively compact and inexpensive.
Optical tweezers are instruments that use a highly focused laser beam to hold and manipulate a small object.
Early modular synthesizers were large instruments that used patch cords to route the signal flow.
Because of its conductive properties and relative chemical inertness, tungsten is also used in electrodes, and in the emitter tips in electron-beam instruments that use field emission guns, such as electron microscopes.
The SF-12 and SF-6D are health-related quality of life instruments that use a subset of these items.
In light of this, we surmise that, since 1997, QOL instruments that use a symptom index have slowly been replaced with subjective QOL instruments.
