Phase measurement by reversible cycle counting - using additional conversion channels for increased sensitivity, inversion rate and reliability

摘要

The phase measurement device for measuring the phase between two electrical signals using reversible cycle counting can be used in laser interferometer instruments for measurement of displace-ment and vibrations. Increased resolution inversion rate and reliability are achieved by adding phase conversion channels and using a different circuit arrangement compared to conventional arrangements. Additional phase conversion units (1) have their first inputs (6) connected to the first signal source (7). The second input (9) of each successive conversion unit is connected to that of the preceding unit via a phase shaft chain (10). The phase shift in each phase shift chain (10) is 'pi' divided by one more than the number of phase shift chains.