RU1800353C - Device for measuring moisture content - Google Patents

Abstract

Usage: dairy industry. SUMMARY OF THE INVENTION: the device comprises a rectangular pulse generator connected in series, an integrator, a flow type primary converter. The converter consists of two plates, the differentiating unit is made in the form of an operational amplifier with feedback resistance. The device contains an inverter, two detectors, a smoothing filter, a digital voltmeter. 3 ill.

Description

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The invention relates to devices for continuously determining the moisture content of butter in a process stream and can be used in dairy enterprises at various types of continuous oil makers.

The purpose of the invention is to increase the reliability of the measurement of humidity and ease of use of the device.

The device includes a capacitive plate-type primary flow converter, a rectangular pulse generator, and a digital voltmeter. An integrator, an operational amplifier with a feedback resistor, an inverter, a detector, a second detector, a smoothing filter are additionally introduced into the circuit.

In this case, a rectangular pulse generator, an integrator, a primary converter, an operational amplifier with a feedback resistor, an inverter, a detector, a smoothing filter, and a digital voltmeter are connected in series. The second inverter is also introduced into the circuit at the output of the integrator, and the second inverter compensates for the zero capacitance of the primary converter and cables, and a variable resistor is connected in series, its engine is connected to the input of the operational amplifier with a feedback resistor through a constant capacitor. The second detector is connected in one connection to the output of the operational amplifier with a feedback resistor, and the second one is connected to the input of a smoothing filter. The amplitudes of the signals coming from the detectors can be equalized by a balanced resistor installed at the output of the detectors in front of the smoothing filter. The primary Converter in the proposed device has a structural design that differs from the known Converter. The transducer is made in vi§

ABOUT

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e of two plane-parallel plates fixed on an insulating mounting evil, which is installed in the hole in the upper part of the oil pipe. The plates are connected by pin contacts with a cable connection with an integrator and an operational amplifier. In the literature studied, no technical solutions having the properties inherent in the proposed hydrometer were found. The object of the invention is achieved in that the direct dependence of the amplitude of the ripple pulses at the output of the differentiating unit is determined only by the shortness of the simplified primary transducer, i.e. humidity of butter.

Fig. 1 is a schematic diagram of an apparatus for measuring humidity; figure 2 - primary Converter; Fig. 3 - time diagrams explaining the operation of the device (type of signals).

The capacitive hydrometer of butter contains (Fig. 1) a rectangular pulse generator 1, an integrator 2, a primary transducer 3, which, with an operational amplifier 4 with feedback resistance 5, constitutes a differentiating block, an inverter b, a detector 7, a second detector 8, smoothing a filter 9, a digital voltmeter 10, calibrated in terms of oil moisture. A second inverter 12 with a variable resistor 13, the motor of which is connected to a constant capacitor 14, can be introduced into the circuit to compensate for the zero capacitance of the primary converter 3 and the cables coming from the converter. A balanced resistor 11 can be installed in front of the smoothing filter 9. To synchronize the detector 7 and the second detector 8, the synchronization inverter 15 can be introduced using the generator 1 so that the output of the generator 1 will be connected through the inverter 15 to the control input of the detector 7 and directly control input of the second detector 8.

The primary transducer 3 consists of two rectangular plates 16 made of stainless steel. And which are fixed on the mounting unit. 18 from ftoroplast (figure 2). The plates 16 are connected via cable pins 17 to cable sections with an integrator 2 and an operational amplifier 4.

The device operates as follows. The primary converter 3 is installed at the outlet of the oil manufacturer. After turning on the device in the network (220 V) from the generator 1 pulses (fit.Z, a) are supplied

to the input of the integrator 2, the output of which receives sawtooth pulses (Fig. 3b), which are fed to the input of the primary transducer 3 and the input of the compensating chain - the second inverter 12 (in case of compensation). Since the primary converter 3 together with the operational amplifier 4 with feedback resistance 5 constitute a differentiating block,

its output receives a signal which is the differential of the amplitude of the signal fed to the input, i.e. rectangular pulse whose amplitude is proportional to the capacitance of the primary converter

(Fig. C, c). This alternating voltage is supplied to the inverter 6, then the inverted signal (Fig. 3, d) passes through the detector 7: where a positive half-wave is extracted and applied to the smoothing filter 9.

The alternating voltage from the output of the differentiating unit also flows to the second detector 8, where a positive half-wave is extracted and also applied to the smoothing filter 9. Filter 9 smooths

constant voltage ripple (Fig. 3, e). The voltage at the output of the smoothing filter 9 is measured with a digital voltmeter. The balance resistor 11, which can be installed in front of the smoothing filter 9, equalizes the amplitudes of the signals coming from the detectors 7, 8. Synchronous detectors made, for example, are used as detectors field-effect transistors synchronized by the generator 1, for which the output of the generator 1 through the synchronizing inverter 15 is connected to the control input of the detector 7 and to the control input of the second detector 8. Initial (zero)

the capacitance of the primary converter 3 and the connecting cables in the absence of oil in the measured space can be compensated by means of a compensating chain by adjusting the variable resistor 13, connected through a constant capacitor 14 with an operational amplifier 4 with feedback resistance 5. Compensation is made by supplying at the input of an operational amplifier (in

in particular, the amplifier K574UD 1A) of out-of-phase sawtooth pulses obtained with the help of the second inverter 12 (Fig. 3, g). Oil moisture meter circuitry can be used in the circuit

automatic regulator, which allows automatic regulation of oil humidity.

- Form of invention

A device for measuring the humidity of butter, including a capacitive plate-type primary converter, a rectangular pulse generator, a digital voltmeter, characterized in that, in order to increase the reliability of the measurement, an integrator, an operational amplifier with a feedback resistor, are introduced into it detachable detector, inverter, second controllable detector, synchronizing the second inverter, filter, compensating circuit, consisting of the third inverter, variable resistor and capacitor, balanced cut istor, and the output of the generator is rectangular

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FIG. 2

pulses are connected to the input of the integrator and the control input of the first detector, and through the synchronizing inverter with the control input of the second detector, the output of the integrator through the primary converter and the compensation circuit is connected to the input of the operational amplifier, the output of which is connected to the input of the first detector and through the first inverter to the input of the second detector, outputs detector bv are connected through a balanced resistor, the balanced output of which is connected through a filter to the input of a digital voltmeter.

FIG. 5