SU830116A1 - Wave recorder - Google Patents

Description

(54) WOLNOGRAPH GOPKO

I

The invention relates to oceanographic measurements and can be used to determine the parameters of wind waves on seas, reservoirs in the coastal zone, and from vessels in drift.

Known autonomous waveguide, equipped with capacitive sensors mounted on the landmark Froude 1.

The disadvantage of this sensor is the low measurement accuracy due to its overgrowing with microorganisms, resulting in a change in the dielectric constant.

The closest in technical essence is a vibrating level indicator, comprising a vibrating probe associated with an oscillator, and a measuring device with electrical contacts located inside the probe. In this case, the vibrating probe is made in the form of a manometric tubular spring with a spring tip, in which electrical contacts 2 are located.

The disadvantage of this level indicator is the low measurement accuracy due to the limited frequency range.

since the manometric tubular spring only works in the low frequency region. In addition, the use of a level vibration alarm is not feasible in marine environments due to the relatively low

the length of the vibrating probe.

The purpose of the invention is to increase the measurement accuracy by extending the frequency measurement range.

The goal is achieved by the fact that a wave recorder containing a vibrating sensitive element and a recorder is equipped with a trigger unit, the output of which is connected to the input of the vibrating sensitive element, and the input is sequentially connected through a shaper of the time interval, the amplifier, the amplitude selector and the first preamplifier output the output of the acoustic receiver, while the second output of the preamplifier is connected to the input of the recorder, and the vibrating sensitive element is designed as tensioned string, reinforced inside the tube, and the tube outside is equipped with an electromagnet.

FIG. 1 shows the wavegraph, section; in fig. 2 is a block diagram of a wave recorder.

The body of waveguide 1 is a tube with an acoustic receiver (microphone) 2 mounted on its upper end. Around the circumference of the tube there are a number of holes 3 evenly spaced along the entire length, serving to reduce the weight of the structure and facilitate water penetration to the sensitive element (string) . An electromagnet 4 mounted in the form of a ring is fastened outside the pipe. A string b is fastened on the screws 5 inside the pipe, which is with the sensing element. The sensing element is made of a ferromagnetic material coated with waterproofing, or of a synthetic filament having a ferromagnetic core at the location of the electromagnet. The length of the string is chosen depending on the height of the investigated waves.

The circuit (Fig. 2) consists of a block 7 for launching an executive 8 and sensing (strings) 6 elements, an acoustic receiver 9, a preliminary, an amplifier 10, a recorder 11, an amplitude selector 12, a power amplifier 13, a driver 14 for the duration of the time interval.

The waveguide works as follows.

Volnograf immersed in water. At the same time, the immersion depth is chosen depending on the wave height so that the lower end of the tube is slightly below the base of the wave. For this, the buoyancy of the structure is selected so that only the upper half of the pipe protrudes into the crane.

When power is applied to the circuit (Fig. 2), the starting unit 7 is activated and a short pulse is sent to the electromagnet. An electromagnet attracts a sensitive element (string) for a time equal to the duration of the triggering pulse t. When this occurs, the string oscillates with a frequency of

l./ft

4 -FVl Ci)

where is the length of the string;

EI - bending string stiffness; m is the mass of a string with an added mass of water.

When moving a string of radius r in a fluid perpendicular to the axis, the attached mass is (per unit length)

SW --3rr-, j, (Z.)

where is the mass of a unit volume of fluid.

It can be seen from equation (1) that the frequency of string oscillation decreases with increasing attached water mass, therefore the frequency decreases with increasing sea wave amplitude and vice versa, the frequency of string oscillation increases with decreasing wave amplitude.

When a pulse is applied from the start-up unit 7 to the electromagnet, oscillations of the string 6 occur with the frequency of free oscillation, however the presence of water leads to a rapid damping of the oscillations. As soon as the oscillation amplitude of the string becomes equal to the sensitivity threshold of the acoustic receiver,

through the preamplifier 10, the amplitude selector (threshold element) 12 is triggered, the signal from which is fed to the shaper 14 of the duration of the time interval. The signal from the imaging unit 14 is supplied to the power amplifier 13 and further

on the electromagnet. The process is repeated, i.e. after the action of each successive pulse. the amplitude of the string oscillations increases, and then gradually fades out. Triggers the threshold device, etc. The signal is recorded using the recorder 11 (frequency meter). Thus, the wave scanner is a system that is acted upon by certain pulses through some intervals of TO. The force of attraction acting in this case is determined by the expression

(--c, co.atr. sirx 3vT i iin ± l si ", (s)

where o is the deviation of the string from the initial

position;

I am the oscillation frequency of the string.

The value of n is determined by the condition

To -t dx-ujTo (1)

On this basis, the period of the pulses is chosen so that the period of free oscillations of the string differs from the period of action of the triggering pulses by 10-15% (that is usually enough to calm the vibration of the structure).

Thus, using the invention to measure the parameters of sea waves greatly increases the accuracy of measurements compared to existing instruments, increasing their reliability and durability.

Claims (2)

1. A wave scanner containing a vibrating sensitive element and a recorder, characterized in that, in order to improve the measurement accuracy by expanding the range of measured frequencies, it is equipped with a trigger unit, the output of which is connected to the input of the vibrating sensitive element, and the input is sequentially passed through a time generator interval, the amplifier, the amplitude selector and the first output of the preamplifier is connected to the output of the acoustic receiver, while the second output of the preliminary the amplifier is connected to the recorder input. 2. A sungraph according to claim 1, characterized in that the vibrating sensitive element is made in the form of a tensioned string fastened inside the tube, the tube being provided outside with an electromagnet. Sources of information taken into account in the examination 1. USSR author's certificate number 594408, cl. G 01 C 13/00, 11/29/76. 2. USSR author's certificate No. 627336, cl. G 01 S 23/00, 03.01.77 totype). 1 s f Js one