SU1704731A1 - Method for determining the presence of hydrobionts - Google Patents

Abstract

The invention relates to the field of hydrobiology and m. used in fish farms and fish protection structures for registration of aquatic organisms. The aim of the invention is to increase the reliability by using the capacitive properties of hydrobionts, which, being in the recording area, affect the frequency characteristics of this area. The method involves creating an alternating electric field in the registration area by applying sinusoidal voltage to the radiating electrodes and measuring its amplitude at the receiving electrodes. The purpose of the invention is achieved by creating a rectangular shape shifted in time with respect to a sinusoidal alternating electric field in the recording area, measuring its amplitude at the receiving electrodes and comparing with the amplitude of sinusoidal voltage. The presence of a hydrobiont in the registration area is judged by the ratio of the indicated amplitudes. The measurement results do not depend on the temperature and chemical composition of the water in the registration area. The described device that implements the method. 2 Il. ate with

Description

The invention relates to hydrobiology and can be used in hatcheries and fish protection structures for the registration of aquatic organisms.

The aim of the invention is to increase the reliability of the determination.

The goal is achieved by using the capacitive properties of hydrobionts, associated, in particular, with the structural features of their epithelial tissues and skin. Due to the significant values of the capacitances of these tissues (in the order of units of microfarads / cm), the electrical impedance of aquatic organisms depends on the frequency of the electrical field in which recording is performed. Thus, the presence of hydrobiont in the registration zone affects the frequency characteristics of this zone, while changes in temperature or chemical composition of water do not have such an effect.

FIG. 1 shows a block diagram of a device implementing the method; in fig. 2 - time diagrams of his work.

The device contains the first signal conditioner 1, the second signal conditioner 2, the switch 3, the first radiating electrode 4, the second radiating electrode 5. the receiving electrode 6. the first selector 7, the second selector 8. the discriminator 9, the registration zone 10, the AC amplifier 11, the first key 12, second key 13, third key 14, matching unit 15, timer 16, first output 17 of timer 16. second output 18 of timer 16, capacitor

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19. third output 20 of timer 16, integrator 21 with reset, selector storage-selection block 22 7. selector-storage sampling block 23, selector control input 24, block 22, And selector 7 element 25, block 22 input 26, block output 27 22, the element And 28 of the selector 8, the first additional input 29 of the element 25, the first additional input 30 of the element 28, the fourth output 31 of the timer 16.

A device that implements a method for determining the presence of hydrobionts, works as follows.

The timer 16 at the output 17 (Fig. 2a) and the output 18 (Fig. 26) synthesizes mutually anti-phase pulse sequences, alternately switching through the keys 13, 14 signals from the output of the former 2 (Fig. 2d) and the output of the former 1 (Fig. 2c ) to the input of the matching unit 15. The same pulse sequences are fed to the inputs of the formers 1,2, where their output signals (square and sinusoidal forms, respectively) are mutually synchronized. Matching unit 15 (for example, a transformer) performs the function of matching the output impedances of the keys 13.14 with the flooding impedance of the radiating electrodes 4, 5, as well as the function of balancing the emitted signal relative to the common wire. Thus, a polyharmonic periodic signal is obtained at radiating electrodes 4.5 (Fig. 2e). The set of keys 13.14 and matching unit 15 is a switch 3.

The electric field generated in zone 10 is recorded by the receiving electrode 6, the signal from which is fed to the input of amplifier 11 (Fig. 2h). The combination of amplifier 11c and capacitor 19 provides integration of the received signal simultaneously with an increase in the signal-to-noise ratio. The key 12 discharges the capacitor 19 at the moments tp of the arrival of pulses from the output 31 of timer 16 (Fig. 2g). Thus, the combination of amplifier 11, capacitor 19 and switch 12 is an integrator 21 with a reset, the output signal of which is shown in FIG. 2i.

From the output of the integrator 21, the signal arrives at the inputs of identical blocks 22. 23. Block 22 pulses at control input 24 memorizes the amplitude value of the signal (samples) at input 26 and stores it at its output 27 until the next pulse arrives from the element 25. Block 23 in conjunction with element 28 works in a similar way. Since the inputs 29, 30 of the elements 25. 28 pulses arrive during the transmission of the square and sinusoidal signals, respectively, the indicated samples by blocks 22 and 23 are taken alternately, i.e. at times of te and tB2, respectively. With this impulses

The tei and; B2 samples from output 20 (Fig. 2e) are slightly ahead of time and do not overlap in time the corresponding tp pulses from output 31 of timer 16 (Fig. 2g).

Thus, at the outputs of selectors

7, 8, signals are obtained that carry information about the maximum value of the integral of a rectangular and sinusoidal signal, respectively.

The discriminator 9 is

serial connection of the differential amplifier (subtractor) and comparator. The differential amplifier produces the difference in the output values of the blocks 22. 23, which in the comparator is compared with the corresponding threshold.

If in zone 10 there is no hydrobiont (Fig. 2, interval). then the signal on the radiating electrodes 4.5 does not differ from the signal on

receiving electrode 6. An uncorrupted combination of rectangular and sinusoidal signals is integrated in integrator 21 and fed to the inputs of selectors 7, 8. The amplitudes of rectangular and sinusoidal

the signals at the outputs of the formers 1. 2 are chosen so that the mentioned values of the integrals at the outputs of the selectors 7, 8 are equal (Fig. 2i. moments ti. 12), the discrimination threshold does not intersect, and

the output of the discriminator 9 is a logical zero (Fig. 2k).

If in zone 10 there is a hydrobiont (Fig. 2. an interval ta-t), then from an electrical point of view it becomes an integrating element

and a small constant time. At the same time, a sinusoidal signal passes through such a link with almost no distortion (Fig. 2c. Ts-te interval), and the square signal (square wave) undergoes a small fuse.

fronts (Fig. 2e, interval). It is obvious that the maximum value of the integral of the meander with littered fronts (Fig. 2i, moment t) is less than the same value of the pure meander (Fig. 2i, moment

ti) i.e. there is a difference Di (Fig. 2i),

Thus, at the output of the selector 8, which performs the analysis of the sinusoidal component, the signal remains unchanged, while at the output of the selector 7. at the output of the discriminator 9 a logical unit appears.

Claims (1)

Invention Formula The method of determining the presence of hydrobionts, which involves creating an alternating electric field by applying a sinusoidal alternating voltage to the measurement zone and measuring the amplitude of this field, distinguished by that. that, in order to increase the reliability of the determination, a voltage of the rectangular shape of the same frequency is additionally supplied and the amplitude of the field created by it is measured, while the supply of sinusoidal voltage and rectangular voltage is carried out alternately, the ratio between the amplitudes is measured, and the presence of hydrobionts is judged by a change in this ratio. ten R Jl 1 but b d 1 I I I I WVWVW 1ADDLLDLA / well tat vg 8f 1vg BI vg 8i vg t I I I I I I I I I I I I I I I 1 tp tp tp tp tp tp tp tp tp tp tp tp tp tp tp tp t and UVIAAAA / V hgdtg N l l Mr. "M N M LT   l Mr. "M N M