SU1002982A1 - Device for measuring damping logarithmic decrement - Google Patents

Description

The invention relates to a measuring technique and can be used to create devices for measuring the relative velocity of introducing radioactive isotopes in the study of the functional state of organs and systems of man. The process under study is the frequency of randomly distributed pulses f (t) f, where fo is the frequency of the pulses at the initial moment of time; X is the logarithmic decrement damping. A device for measuring the logarithmic damping decrement containing a discriminator, a sensor, three counters, a recorder, two registers, a code-frequency converter and an element OR 1 is known. A disadvantage or a known device is low accuracy and fast action. The closest in technical essence to the proposed A device for measuring logarithmic damping decrement containing sensor, driver, pulse counters, registers, counter-registers, code-frequency converter, timer, delay line and, the dividing and registering unit 2. The disadvantage of this device is its low speed. The result of the conversion is formed in a time equal to ST (T is the time interval specified by the timers k). In addition, the device is quite complex. The aim of the invention is to increase the speed and simplify the device. The goal is achieved in that the device for measuring the logarithmic damping decrement contains a sensor whose output is connected via a driver to the counting input of a pulse counter, the synchronization input of which is connected to the timer output and the synchronization inputs of the second and third counters to the first inputs of one group of elements of coincidence, and the block of division, two blocks of the addition of pulse sequences are introduced. and another group of elements of coincidence, with the first inputs of the latter being connected to the outputs of bits

the second counter, pulses, and the second inputs - to the outputs of the bits of the third pulse counter, the counting input of which is connected to the output of the first block — the addition of pulse sequences; the input of the second counter and the output of the second block of the addition of pulse sequences, the first input of which is connected to the output of the imaging unit, and the second input - to the output of the first group of coincidence elements, the other cat The wire is connected to the outputs of the second counter.

The drawing shows the structure electrical circuit of the device.

The device includes a sensor 1, a driver 2, pulse counters 3, 4 and 5, a group of elements 6 and 7 of coincidence, blocks 8 and 9 of the addition of pulse sequences, a divider 10 and a timer 11.

The device works as follows.

From sensor 1 through the driver 2 to the counting input of the counter 3 pulses pulses are received with a frequency

; lt) f e-. (one,

about

During the time T, set by timer 11, the next number of pulses will go to the input of the pulse counter 3;

r t

N, -J e-4 (l-e-. C2,

about

at time T, the signal from the output of timer 11 counts the pulses of the counter 3 pulses to stop, and the same signal will allow the counts to be counted by counters 4 and 5. At the input of block 8 during the second time interval T, the pulse sequences will arrive

(1st-2T) A (.- (e-, -e--).

i

The pulses through the pulse sequence addition unit 8 are fed to the input of the pulse counter 4, which, together with the group of coincidence elements b, forms the binary frequency multiplier.

The work of the latter is described by the expression

m - N4 -N (4)

where N, is the number of pulses received at the input of the group of elements 6 coincidence; N is the number of pulses received at the input of the group of elements 6 coincidence;

- the numerical value of the control code

- the conversion factor of the counter 4 pulses. as N ,, N, then

,,

(five)

Na-n

m

The number of pulses at the output of block 8 of the addition of pulse sequences is equal to

N N 2 + N3. (6)

From expressions (5) and (6) follows

. .)

N

m

From here

N, ..

(eight)

The pulses from the output of block 8 of the addition of pulse sequences are fed through a divider 10 with a division factor T to the input of block 9 of the addition of pulse sequences.

Counters 4 and 5 pulses together with block 9 of the addition of pulse sequences and a group of elements 7 constitute a divider whose operation is described by the expression

fVAn

(9)

c3N5

where NJ is the number of pulses received from the output of block 9 of the addition of pulse sequences to the input of the counter 5 1U (pulses;

(, is the number of pulses received from the output of block 10 division to the input of block 9 of the addition of pulse sequences.

If the pulse counter 5 presets the number Njn, then

T 1

in time equal to 2T, the number will be formed in it:

N4

. . .

J T —N7 N N,

 m

m,

  . (lo)

Consequently, in the counter 5 pulses in a time equal to two intervals T, we obtain the numerical value of the logarithmic damping factor. In a known device, the measurement is performed in three intervals T.

Claims (2)

1. Author's certificate of the USSR N 737875, cl. G 01 R 27/26, 1977. 2. The author's certificate of the USSR 1 737876, cl. G 01 R 27/26, 1978 (prototype).