SU1597541A1 - Apparatus for reversive counting of bands in interferometers with internal phase modulation - Google Patents

Abstract

This invention relates to instrumentation technology. The purpose of the invention is to improve accuracy by eliminating the false alarms of the band counter. The device contains a pulse shaper 1, a counter 2 of the duration of the intervals between pulses, and a register 8. Shaper 1 generates two pulses, the first of which is related to the phase of the modulation signal of the interferometer, and the second is related to the level of the interference signal. The decision on the band count is made when the time interval between pulses changes abruptly. 1 hp f-ly, 1 ill.

Description

315

The invention relates to a monitoring and testing technique and may be

used in interferometers with

internal phase modulation before the band count.

The purpose of the invention is to improve accuracy by eliminating the false alarms of the band counter.

Pa drawing shows the block diagram of the device.

The device consists of serially connected pulse driver 1, counter 2 of the pulse interval, subtractor 3, comparator 4, element 5, reversible counter 6 and display unit 7, register 8 connected between the output of counter -2 and the second input of the subtractor 3, a digital o setting circuit 9, the output of which is connected to the second input of the comparator 4, connected in series to the comparator 10, whose input is connected to the output of the subtractor 3 and the output to

the second input of the element H 5, and the element 11, the second input of which is connected to the second output of the comparator 4, and the output to the second input of the counter 6 and the number setting circuit 12.

. The device operates as follows.

The shaper 1 in each measurement cycle generates two pulses: the first at the moment of time associated with a specific phase of the modulation interferometer, and the second at the moment when the interference signal is equal to zero. Counter 2 generates at the output a number proportional to the time interval between two pulses. This number is written to

Q

five

0

14

register 8. In subtractor 3, the number is subtracted, which is proportional to the current time interval, from the number that is proportional to the time interval during the previous measurement cycle. When PREVENTING the result of the threshold subtraction, the comparator 10 generates a signal for counting the whole band. This signal, depending on the signals from the comparator 4, determined by the sign of the result of the subtraction, is fed through the elements 5 and 11 to the input + or -. of the counter 6. The result of counting the bands from the counter 6 is fed to the input of the display unit 7.

Claims (1)

Invention Formula A device for reversing the counting of bands in interferometers with internal phases Ovian modulation, which contains a pulse shaper and a reversible counter, characterized in that, in order to improve accuracy, it is equipped with a series-connected pulse duration meter, the input of which is connected to the output of the pulse formaker, the subtractor, the first comparator and the first element I, whose input is connected to the first input of the reversible counter, the recorder connected between the output of the duration meter between impulses and the second input of the subtractor, serially connected by the second comparator, the input of which is connected to the output of the subtractor, and the output to the second input of the First element And, and the second element And, the second input of which is connected to the second output of the first comparator, and the output input reversible counter.