Phase measurement, traceability, and verification theory and practice

Methods are presented that allow high-resolution (better than ±0.5 m°) relative and absolute phase measurements between sine waves to be made at, or in the vicinity, of angles of 0°, 60°, 90°, and 180°. Three of these methods appear to be completely independent of each other. They involve the use of 180° phase verification bridges, the use of a sine wave as a zero-degree intrinsic standard of phase, and the use of quadrature phase meters, respectively. A representative sampling of data comparing the different approaches is presented