The Krohn-Hite Model 6500 Phasemeter measures the phase angle between two waveforms of coincident frequency, over a range of 3 Hz to 5 MHz, and provides a typical accuracy of 0.02°, with 0.01° resolution.
A 5 digit planar gas discharge display provides direct readout of the phase angle from 000. 00° to 360. OOO. The 6500 accepts input voltages from 0.01 volts RMS to 120 volts RMS. The fluctuations or inconsistencies normally encountered in phase angle readings near zero and 360' (sometimes referred to as ambiguity) are eliminated by a unique network in the 6500 that permits readings a s small as 0. 01° to be observed, without the need of changing ranges or 180° shifting.
In addition, the circuitry of the 6500 significantly reduces the effects of distortion and noise on phase accuracy. An analog output on the rear panel provides a DC voltage equal to -10 mv/degree phase, for use with an external meter or recorder. An optional BCD output is also available. A readhold switch also provides continuous display of the phase angle reading, or holding of the reading for an indefinite period.