Adding Certainty to Measurements

摘要

Webster defines calibrate as "to standardize (as a measuring instrument) by determining the deviation from a standard so as to ascertain the proper correction factors." To perform a calibration, you need a reference and an instrument with which to measure deviation. For RF power calibration, a common test method uses a bolometer and a balancing bridge. Bolometers are made from various materials that have a stable and relatively large resistance temperature coefficient. Platinum often is used because of its very wide temperature range and nearly linear change in resistance vs. temperature difference.