SU757947A1 - Device for measuring spin-spin relaxation - Google Patents

Description

The invention relates to the field of measurement technology, in particular, to devices for measuring the time of spin-spin relaxation by methods of radio spectroscopy, in particular by pulsed methods of nuclear magnetic and nuclear quadrupole resonances, and can be used to emit the physicochemical properties of various personal substances and. other ¹

There are known devices containing a programmer, a transmitter of radio pulses, an oscillating circuit with a test sample, an echo receiver and a recorder, with which the spin-spin relaxation time is determined by the graph of the measured echo-signals amplitudes from the observation time [11.

The disadvantage of such devices is 2! It is difficult and time consuming to determine the spin-spin relaxation time, carried out by manual processing of experimental data.

The closest technical re- * shein is a device consisting of programmers, a transmitter of radio pulses, an oscillatory circuit with a test sample, a receiver of echo signals, a time meter measuring ICTOR-3 '

2

shafts, amplitude-time converter and oscilloscope [2]. The spin-spin relaxation time is determined visually from the angle of inclination of the straight line, obtained as a result of the logarithmic amplitude-time conversion of the measured amplitudes of the echo signals.

The disadvantage of this device is also the complexity and complexity of determining the time of spin-spin relaxation, which requires additional time for processing the measurement results. In addition, the measurement range of the time of the spin-spin re> laccia of the specified device is limited by the dynamic range of the transducer.

The aim of the invention is to reduce the complexity and increase quickly5 actions in a wide range.

"The goal is achieved by

that a known device containing a programmer, a radio transmitter transmitter. owls, we investigate oscillation circuit ⁵ with emym sample echo signal receiver

and time interval meter,

equipped with a controlled memory unit, a control unit, a comparator, with the output of the receiver echo-signal connected to the input of the controller

757947

four

memory unit, one output of which is connected to one of the inputs of the control unit and to the first input of the comparator, and the other output through the amplifier to the second input of the comparator, the output of which is connected to the input of the programmer and the second input of the control unit, while the output of the programmer is connected to the third input of the control unit, one output of which is connected to the control input of the controlled eaming unit, and the other output - to the time interval meter.

FIG. 1 shows a block diagram of the proposed device ‘, FIG. 2-5 stress plots explaining his work.

The device contains a programmer 1, a transmitter 2 radio pulses, an oscillating circuit 3 with the test sample, a receiver 4 echo signals, a controlled memory unit 5, an amplifier 6, a comparator 7, a control unit 8 and a time interval meter 9.

The device works as follows. When the test sample, which is located in the coil of the oscillatory circuit 3, is excited with powerful radio pulses of the transmitter 2, spin echo signals appear at the output of the receiver 5 (see figure 2). In this case, the video pulses generated by the programmer 1 simultaneously arrive at the input of the control unit 8. Using the control unit 8, if necessary, pre-set the reference time η (where n = 1,2,3, ..) is the beginning of which the relaxation process under study is one-component, i.e. starting from which the required time of spin-spin redoxing T ₂ belongs to only one slow-falling component.

Thus, when the first echo arrives at the input of the controlled storage unit 5, its first output (see fig. 3) will display a voltage level and _η equal to the amplitude of the fixed echo signal, which is applied to one of the inputs of the control unit 8 and to the first (reference) input of the comparator 7. At the same time, the second output of the control unit 8 will receive a pulse of the beginning of the time, fixed by the time interval meter 9 (see Fig.5). Subsequent echoes received at the input of the controlled memory unit 5 will appear at the second output in the form of voltage pulses (see Fig. 4). Reinforced by the amplifier 6, these pulses are fed to the second input of the comparator 7. At the moment equal voltage V., = (Y ^ cUsch, where is the amplitude of the pulse at the input of the amplifier 6) at the output of the comparator 7 will receive a pulse that simultaneously goes to one of the inputs of the control unit 8 to fix the measured time interval and to the input of the programmer 1 to turn off the last .

The gain to the amplifier 6 is set to a certain value depending on the experimental conditions - the degree of attenuation of the relaxation process and the minimum possible setting of the interval from _0. Since

then at the moment of equality

^and n ^{= and} t> ^k ' ^ex p [^ ίт-г,)] When measuring the value of m in real time, set the gain factor k = 2.718, which corresponds to 4 ί = Τ ₂ -ΐ ₀ (ιτι-η) (see .fig. 5).

In comparison with known devices, the use of the proposed device for measuring the time of spin-spin relaxation provides the following advantages:

- reduction of labor input and increase of speed in a wide range of measurement due to automation of the measurement process; the possibility of measuring the time of spin-spin relaxation both in real and on a given time scale, which is established by adjusting the gain of the amplifier, which allows us to further accelerate the process of measuring the time of spin-spin relaxation of slowly occurring relaxation processes; improvement of measurement accuracy due to the absence of a reference error.

Claims (1)

Claim A device for measuring the time of spin-spin relaxation, containing a programmer, a transmitter of radio pulses, an oscillating circuit with a test image, an echo receiver and a time interval meter, characterized in that, in order to reduce labor intensity and increase speed in a wide range, it is equipped with a controlled unit memory, an amplifier, a control unit and a comparator, with the output of the echo receiver connected to the input of the controlled memory block, one output of which is connected to one of the inputs s control unit and to the first input of the comparator and the other output through the amplifier - a second input of the comparator, the output of the latter is connected to the input of the programming device and the second input of the control unit, and programming the output is connected to the third input unit upravle5 757947 6 This unit is connected to the control input of the controlled storage unit, and the other output to the time interval meter.