SU518713A1 - Device for measuring the frequency of signals - Google Patents

Description

(54) DEVICE FOR MEASURING THE FREQUENCY OF SIGNALS | NUCLEAR SQUARE-FIELD RESONANCE

an electronic detector loaded on a fiscter (low frequency,

The differential frequency period period HsNiepHTeneM 6 is an electron-counting frequency meter operating in period measurement mode.

The device works as follows.

A pulse oscillator 1, controlled by a program block 2, excites the spin system of the sample, receiver 3 receives signals of nuclear indices or spin echo, amplifies them, and supplies them to one of the inputs of the frequency comparison circuit 5 and the difference 1 peak 1. The signal from generator 4 of known frequency is fed to another input of the comparison circuit. The frequency of the signal on the output of the comparison circuit is the difference between the frequencies of the signals from the receiver output and from the generator of a known frequency. Period meter 6, the start of which is made at the time of occurrence

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The present invention makes it possible to record small shifts of the NQR frequencies as a result of external influences, such as pressure, temperature, internal stresses in the sample. It allows to significantly simplify the method and increase. Accuracy of measurement of some substance constants, for example, the quadrupole coupling constant еО.С |, asymmetry parameter

the gradient of which floor and their derivatives with respect to the parameters of external influences,

The invention can be found under the conditions of scientific research in the field of factory and factory, thorium when studying the properties of non-conductor 1С11Х material HjiaoB,

signal, measures the period of the received frequency response,

In the case of operation with a direct gain receiver, the frequency of the signal is defined as iv "{„ il / T.

, SIGN. And p

where is the law; signal frequency

 - ЖР;

{- frequency of the generator of known frequency;

- p - the period of the difference frequency. In the case of superheterodyne reception, the frequency of the signal will be

Lign G1: TER ..

nie {- the frequency of the heterodyne,

, e1 gaika,

The signs in fsmules are determined by the selection of the settings of the generators.

Absolute measurement error of the frequency | T10ta signal :.

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and

Claims (1)

Invention Formula A device for measuring the cis frequency of nuclear quadrupole resonance (NQR), consisting of a pulsed incoherent NQR spectrometer, which contains a pulsed self-oscillator, a program block and a receiver. This is due to the fact that, in order to overwhelm the nausea of measuring the frequency of the signal, a generator of a known clock, a frequency comparison and differential frequency selection circuit and a difference frequency period meter, the input of which is connected to the output of the comparison circuit, one of which is connected to the output, are entered into it. the receiver of the signals, and the other input of the co-ent unit with the generator output is known frequency. J