SU507813A1 - Device for measuring the attenuation coefficient of acoustic oscillations - Google Patents

Description

step onto the receiver 4, amplify, detect and feed a selector 15 to an oscilloscope 16, the sweep of which is triggered by pulses of synchronizer 1. The pulses of synchronizer 1 trigger a variable delay circuit 9, generate a steroid pulse delayed relative to the synchronization pulses, automatically as controlled and manually, the time interval / in / The building pulse goes to the selector 5 from the output of which one of the selected echo signals in this case, the second pulse cepHvr, (Fig. 2) is fed to the logarithmic and the amplitude-time converter 13 interval, from the output of the latter, a pulse Tj fg- (J controls the key 12, passing at the input of the reversible counter 11 the pulses of the reference frequency generator 15. The pulses of the synchronizer 1 are fed to the input of the divider 6 connected to the counter control circuit 10 , the program master, trigger 7, the duration of the output pulses of which is equal to where P is the division factor of divider 6, equal to the number of measurement intervals. The voltage levels of U and U are the trigger stroke 7, corresponding to the levels of logic 1 and logic O, can be adjusted manually to select: 1 two pulses from a series of reflected echo pulses. The presence at the input of circuit 9 of a variable delay level, in this case, determines the selection of the second pulse of a series of signals with amplitude U.. For the duration of the trigger pulse duration p T, a reversing generator of the reference frequency generator passes to the reversible counter, the number of which in each burst is proportional to T fg-Ui. (Fig. 2, 3, i), in this case, the counter operates in Summing mode T p) 1 output trigger voltage corresponding to the logic level O, the counter control circuit 1O switches the counter to the subtraction mode while simultaneously changing the gate delay, the next pulse is selected from a series of echo pulses, the amplitude of which is converted into the time interval Tr, fgLI (Fig. 2.3). In FIG. 2 a, b, c, d, d, e are given voltage diagrams in the case when trigger pulse pulse 7 with amplitude arrives at the time delay circuit 9. FIG. 2, the time scale was changed to show that at a logic level O (UtpyJ Rbi, another pulse from the series of echo signals (not shown in Fig. 2), which is converted into time interval T, is selected. Thus, the proposed device allows E1 to measure the coefficient the decay of acoustic oscillations -KCfgUregUj where a is the divider division factor, can be chosen as derivative within units-hundreds, tJjUj are the amplitudes of the corresponding pulses from a series of echo signals; G is the time interval between them, and averaging is performed over P K is the coefficient of processionality. In Fig. 3, a change in the time scale is also made. In Fig. 3, trigger pulses 7 (Fig. 2 g) are plotted, in Fig. 3 b, there are pulses from the output of the U control circuit, where - total counting time in the forward and reverse direction, TSs - the time of indication of the counting result, in Fig. Sv - pulses with a splitter 6 received at the input of the unit 14 of the program, consisting of a step voltage generator and a step counter, with a pin which step voltage is supplied to the adder 8. Step voltage voltage (FIG. 3 d) is necessary for the sequential selection of different pairs of measured pulses from a series of reflected echo signals (Fig. 3 d, e, g). Gluing and non-parallelism of the surfaces of the transducers and the sample under study (in the case of solids) leads to a violation of the exponential decay law of the reflected echoes, so it is advisable to average the measurements over selected pairs of pulses from a series of echoes. The number of pairs depends on the total number of pulses in the series and is set in the program master. Formula of the Invention A device for measuring the coefficients (x}) of an acoustic oscillation attenuator containing an acoustic chamber with transducers, a synchronizer, a high-frequency pulse generator, a receiver, a variable delay circuit with a gate former connected to the synchronizer, a selector and an oscilloscope, that, in order to increase the accuracy: ti and

measurement efficiency, the device is equipped with a statistical averaging system consisting of a divider connected to a synchronizer, connected to a program master divider, a meter control circuit, a reversible counter and a trigger with an adder, the other input

The njxM-V.iNMM patch is connected to the output, and the adder's output is connected to. (“delay time, connected to the network” (the logarithmic input band and the 5th line of the amplitude-time interval, and connected to the sensor | yc dial (Frequencies.

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