SU1415067A2 - Level gauge - Google Patents

Abstract

The device is designed to simultaneously measure the level, temperature and electrical resistance of the monitored medium. The sensing element in the form of a thermocouple 3 is mounted on the lead screw 2 with the ability to move along it by means of a roar. The motor is connected to the measuring reichord 4. Information about the level and t-re in the form of signals from the reichord and thermocouple is fed through a coater 19 and analog-digital converter 20 to a memory register 21. Information about contact with the medium and its resistance goes from one of the leads to the phase modulator 5 and then through the phase shift converter 7 and the switch 9, controlled by the synchronizer 8, to the counters 10 and 13 о Comparison diagram P of the digital information of the counter 10 with the value on the master device 12 control state trigger and 16- and simultaneously generates a working signal for the synchronization unit 18, which provides the formation of pulses that permit the indication of the contents of the counter 13 (medium resistance information) and enable the interrogation, by the switch 19 of the measuring voltage 4 and thermocouple 3. . cl

Description

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The invention relates to an instrument structure, can be used in the chemical industry, for example, when growing single crystals and in improving the device according to the author. No. 1093906.

The purpose of the invention is to expand the functional capabilities of the device by providing simultaneous control of level, temperature and electrical resistance.

The drawing shows a functional diagram of the device.

The device contains a reversing 15 engine 1, a lead screw 2, a thermocouple 3, a measuring reochord 4, a phase modulator 5, a generator 6 of a sinusoidal signal, a phase shift converter 7, the first block 8 20 the first switch 9, a reversible counter 10, the first circuit 1 compare digital information, the first setting device 12, the pulse counter 13, the second comparison circuit 14, 25 the second setting device 15, the RS trigger 16, the matching unit 17, the second synchronization unit 18. synchronization, the second switch 19, the analog-to-digital generator (ADC) 20 , register 21 pas mt and crucible 22 with melt.

The device works as follows.

The reversing motor 1 moves the thermocouple 3 relative to the crucible 22, where the melt is located. Thermocouple - melt is included in one of the arms of the phase modulator of the pulser fed by the reference voltage of the generator 6. The phase modulator - the converter 5 converts the resistance of the thermocouple system - the melt into a phase shift of the information signal U relative to the reference voltage Nala. . Oscillator 6 Phase shift is converted into a number of pulses by the phase shift converter 7 and through the first switch 9, controlled by the first synchronization unit 8, advances to a reversible counter 10, which together with the first digital information comparison circuit 55 and the first driver 12 forms the main control loop. Reverse account 50

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Tick 10, filled with pulses at times t, and t. on the direct and inverse inputs, is a device for calculating the difference in phase shifts dcf (t,) -bq. (t ,,). The resultant information of the reversible counter 10 with the frequency of operation of the first synchronization unit 8 is compared with the first digital information comparison circuit 11 with a predetermined value at the first driver 12.

Suppose thermocouple 3 is above the melt and moves down. The resulting information of the reversible counter 10 after isolating the phase difference is equal to lsr (t,) - bCfCt) N. This value is compared in each operation cycle of the first synchronization unit 8 using the first comparison circuit 11 and the first setting device 12 with the value of mcc PR of the thermocouple 3 above the melt K „i. no change in the state of the first circuit 11 occurs.

at the moment of the contact of the melt by the thermocouple, the resulting information of the reversible counter 10, is proportional to the difference in phase shifts, for this cycle of operation of the first synchronization unit 8 becomes greater Tov. As a result, the first comparison circuit 11 changes the short circuit of the flip-flop 16. The change in the logic signal at the top of the first comparison circuit 11 is the operating signal for the second synchronization unit 18, which provides pulse shaping, the contents of the counter 13 pulses (resistance of the melt) on the indication, t, j and t ,, are the resolution of the second KOMi-iyTaTopoM 19 to interrogate the voltages of measuring rheochord 4 and thermocouple 3.

The main circuit of the control circuit is adjusted so that when added, the meter reacts to the magnitude of the resistivity jump in the thermocouple-melt system, which is set for this melt by the first master device 12 The necessary jump in resistance is formed at the moment the thermocouple transitions from one medium to another.

Current information on the magnitude of the resistance of the melt at the time of its contact with the thermocouple is recorded

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a pulse counter 13; a. The upper and lower limits of resistance are set by the second driver 15 and compared in a second digital information comparison circuit 14.

. The working signal for the second block. 18, the synchronization pulse is a voltage pulse, formed at the time of a jump in resistance at the output of the first comparison circuit 11. The second synchronization unit 18 generates pulses controlling the operation of the counter of 13 pulses, the second switch 19 and the recording of information in the memory register 21.

Register 21 of the memory records information received via ADC 20 and the second switch 19 from measuring rheochord 4 and thermocouple 3, which corresponds to measuring the level and temperature at the point of contact of the melt, respectively.

The device provides for output of measured values to one indicator. The output signals of the device are: - melt resistance, melt level, Ugbuj melt temperature.

The change in the state of the RS flip-flop 16 creates a resolving potential through the matching unit 17 for reversing the engine 1 upward to the separation of the thermocouple from the melt. In this second

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The synchronization unit 18, by the signal of the first comparison circuit I 1, generates a pulse t of enabling the recording of information processed in the A / D converter 20 in memory register 21 and outputted to an indication. Thus, the results of measuring the resistance, level and temperature of the melt are displayed on the reading device.

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Claims (1)

Formula is invented Level gauge for auth. No. 1093906, characterized in that, in order to extend the functionality by providing simultaneously control of level, temperature and electrical resistance the second synchronization unit and the second switch, the analog-digital converter and the memory register, in series, are additionally introduced into the environment; made in the form of a thermocouple, the conclusions of which and the output of the measuring rheochord are connected to the inputs of the second switch, the control input of which is connected to the third output of this The synchronization block, the first output of which is connected to the pulse counter, is the second output. - with the memory register, and the input - with the counting input of the RS-flip-flop.