SU134904A1 - Ultrasonic concentration meter solutions - Google Patents

Description

Ultrasonic concentrators of solutions are known, including an emitter and receiver of ultrasonic vibrations, a high-frequency generator, a receiving amplifier-limiter, an amplifier-limiter of the generator signal and a phase detector connected to the latter two with a recording device attached to it.

In the proposed ultrasound concentrator of the solutions, as compared to the known ones, automatic compensation of the faults caused by changes in the ultrasound velocity in the controlled medium during fluctuations of its temperature is provided. This is achieved by the fact that an intermediate membrane, through which ultrasonic vibrations are transmitted in a concentrator, is made of a material whose temperature coefficient of ultrasound has an opposite sign with respect to the temperature coefficient of ultrasound velocity in a controlled environment, or in the form of a hard shell with filling (11). having the required sign of the temperature coefficient of ultrasound velocity.

FIG. 1 shows an electrical diagram of an ultrasonic concentration meter; in fig. 2 is a schematic diagram of a concentrator gauge with a solid membrane for measuring the concentration or density of solutions in open lines and collections, in section; in fig. 3-diagram of the part of the sensor head with a liquid membrane, in section.

From a high-frequency master oscillator assembled according to an oscillation circuit on the 6XZP-lamp L pentode, high-frequency electrical oscillations are sent to a power amplifier assembled on a 6P14P-lamp L pentode according to the cathode follower circuit. The cathode load of the power amplifier is a tuned oscillating circuit consisting of the inductance LI, the primary winding of the transformer, the inductance Z-2 of a step-down rheostatic capacitive phase shifter, the capacitance of the radiating piezoelectric element of the IP sensor and the capacitor of the connecting coaxial cable.

No. 134904-2

The electrical oscillations are converted by the radiating and acoustic element into ultrasonic oscillations of the same frequency, which, after passing through the control solution, are fed to the receiving piezoelectric element / 7/7 with some phase shift relative to the oscillations on the radiating piezoelectric element I / 7.

To compensate for temperature variations, membranes with a temperature coefficient (ultrasonic velocity, having the first sign opposite to that of the temperature coefficient -, sound speed in a controlled medium, are installed in the sensor between the piezo elements and the controlled medium. The thickness of these membranes is calculated according to the corresponding mathematical formulas. All known solid bodies that can be used as a material of the membranes have a negative sign of the temperature coefficient - (; therefore, They can only be used for liquids that have a positive sign of the temperature coefficient of ultrasound velocity 1. In particular, this class of liquids includes, in particular, all aqueous solutions in a considerable range of concentrations and temperatures.

A sensor with membranes from a solid can be made in the following form (Fig. 2). The emitter and receiver of ultrasonic vibrations are mounted in identical heads, housings. They are mounted on the thread up to the stop in racks 2, rigidly fixed between each other by tubular clamps 3. Screw connections between the housings, adapter sleeves 4 to the lugs 5, as well as the output of coaxial cable 6 sealed with rubber pads 7 and 8. Racks, latches, and external parts of the heads are made of 1-plexiglass. The housings of the housings are piezoelectric membranes 9. The electrical connection of the piezoelectric plate, pressed to the membrane, with a metal braid of the cable is shown through a JO tab of a brass foil ring, pressed by the piezoelectric element into the recess to the membrane, spiral spring and a metal pattern. Korean braid cable to the inner end of the sleeve 2. The electrical connection of the upper plates with conductor.1 residential cable is carried out through the de.mpfer 12, coil spring /, and metal contact 14, in rum Pinned cable core.

For liquids having a negative sign of the ambient temperature ultrasound temperature coefficient, temperature compensation is provided by means of a liquid membrane with a hard shell. The fluid used is a water or an aqueous solution having a positive temperature coefficient of ultrasound velocity of the required value. The thickness of the liquid layer (filling) of the membrane is also calculated according to the corresponding mathematical formulas. The implementation of the liquid membrane is illustrated in FIG. 3, where indicated; piezoelement / 5, head housing 16 sensor, hard shell / membrane, liquid layer 18 (version) of the membrane; the remaining elements of the sensor design are similar to (, the instructions in Fig. 2.

As already mentioned, the ultrasonic oscillations of the 1st 1 are applied to the receiving piezoelectric element PP with some phase shift; this phase shift is proportional to the measured concentration. Ultrasonic vibrations are transformed by a receiving piezoelectric element into electrical ones, which are fed to a receiving amplifier-limiter consisting of four stages, assembled according to a resonant circuit on 6HZP pentodes - lamps, / 7z, L, Lz and // 6. The last stage (lampLb), the anode load of which is: internally tuned oscillator circuit L, - -

C | - Cj phase detector (lamp JIj operates in AL mode P11T} of a single limiter. Oscillating cohorts of anode loads with lam .7; - ,,, / LI, //; -, Л, 1 to increase the stability of the phase characteristics of the receiving amplifier-shunt conditioner mn respectively /,., and R. ;. The internal oscillating circuit of the phase detector, in addition to the receiving signal, also receives electrically oscillations of a stabilized amplitude from the emitting piezoelectric IE through the system: contour at the center of the cathode of the lamna. T, is the secondary noH. izhayuscha, inductance /., tr Ansformat, inductance / -2 speed rheostatic capacitive phase; Atel, capacitors C; C and switched by switch // resistance; resonant limiting amplifier, assembled on neitodo bZhZN -lava // 8, the anodic load of which is riacirovanny B1piney spade) 1th contour L.- -,; phase detector.

A cathode load phase detector detects the HCJstable-state current, a non-rational) phase phase, applied to an external oscillation circuit and, therefore, it detects a co-controlled solution. Part b) of that voltage from the resistance of K nostunat to the recording pre-standard electronic potentiometer of any type, for example, EPP-09, the scale of which is graduated in concentration units to record the measured concentration. In the cathode load of the phase detector, there is an iJirTHKaTOp switch. The MLM (tiia-.M24) micron-ammeter, the needle of which is also calibrated in units of the measured; 1 solution parameter; regs -: and the operating current of the phase detector is monitored by a potentiometer Rz; - ,.

The negative direct current current coming from the case; the body of the source of stabilized power through the blocking resistance to the dial indicator and the load resistance of the registering nuurum, is used to set it to zero.

Compensation of the initial shift of the effective eiyala (corresponding to the initial concentration of the monitored solution) can be made in the radiating channel in equal steps of 16 ° in the ranges of 0 + 160 ° in one position of the switch P-2 and in the diameter of 180-1-340 In its other position and smoothly receiving channel in the range of 0 + 40 ° with a potentiometer at the input of the lamp L. This provides the possibility of using the same electronic measuring unit for sensors with different distances between the radiating and receiving piezoelectric cops.

The control of changes in the amplitude of the input signal required in some technological processes for the qualitative analysis of their flow can be carried out simultaneously with concentration measurements with the weakness of a full-wave detector assembled on a point semiconductor diode Dy at the input of the lamp L of the receiving amplifier-limiter. A part of the corrected voltage matching / .2 no. To the recording instrument.

The switch Jaz serves to periodically check the normal operation of the receiving channel (at position o) and the radiating channel (at position b). At the indicated positions of the Yaz switch, the phase detector registers only the output amplitudes of the signals of the receiving and radiating signals. The position in the switch I corresponds to the measurement of the concentration of the controlled solution.

The power supply of the electronic measuring unit circuit elements by a constant and variable stabilized voltage is carried out on a circuit including: a power transformer Tp; a positive voltage rectifier assembled on DG-Ts27 semiconductor diodes according to a bridge circuit; negative rectifier

-3 -up to 184904

34904- 4 voltages on the same i-semiconductor diodes; two gas voltage regulators assembled on Ld and Liu lamps of the SG-1P type.

Subject invention

An ultrasonic concentrator of solutions, including an emitter and receiver of ultrasonic vibrations, a high-frequency generator, a receiving amplifier-limiter, an amplifier-signal limiter of the generator and a phase detector connected to the last two with an instrument connected to it, in order to provide compensating for errors caused by changes in the ultrasound velocity in a controlled medium with variations in its temperature, an intermediate membrane through which at the end The ultrasound oscillation device is transmitted by a meter; it is made of a material in which the temperature coefficient of the ultrasound velocity has the opposite sign with respect to the temperature coefficient of the ultrasound velocity in a controlled medium, or in the form of a solid shell filled with liquid that has the required sign of the temperature coefficient of the ultrasound velocity.

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