SU684422A1

SU684422A1 - Automatic electronic moisture content meter

Info

Publication number: SU684422A1
Application number: SU772479740A
Authority: SU
Inventors: Владлен Семенович Ройфе
Original assignee: Научно-исследовательский институт строительной физики
Priority date: 1977-05-29
Filing date: 1977-05-29
Publication date: 1979-09-05

Description

(54) АВТОМАТИЧЕСКИЙ ЭЛЕКТРОННЫЙ ВЛАГОМЕР(54) AUTOMATIC ELECTRONIC WATER

1one

Изобретение относитс к измерительной технике и может быть использовано дл измерений влажности твердых , жидких и сыпучих веществ.The invention relates to a measurement technique and can be used to measure the moisture content of solid, liquid and particulate matter.

Известны электронные влагомеры с емкостными первичными преобразовател ми , в которых мерой влажности вл етс полное сопротивление (проводимость) емкостного преобразовател с материалом 1. На результаты измерений таких влагомеров вли ет активна проводимость материала , поэтому они неточны.Electronic moisture meters with capacitive primary transducers are known, in which the impedance (conductivity) of a capacitive transducer with material 1 is a measure of moisture. The measurement of such moisture meters is influenced by the active conductivity of the material, so they are inaccurate.

Известны также электронные влагомеры с емкостными первичными преобразовател ми , результаты измерений которых регистрируютс цифровым индикатором 2.Also known are electronic moisture meters with capacitive primary transducers, the measurement results of which are recorded by digital indicator 2.

Эти влагомеры невозможно использовать в системах автоматического контрол и регулировани влажности, поскольку они дают результаты измере .ний в условных единицах.These moisture meters cannot be used in automatic humidity control and regulation systems, since they give the measurement results in arbitrary units.

Наиболее близким техническим решением к изобретению вл етс влагомер , содержащий емкостный первичный преобразователь, измерительный двухполюсник с модулируемыми параметрами , высокочастотный генератор, модул тор , нуль-орган и балансирующий орган 3. Этот влагомер выгод-: но отличаетс от других известных диэлькометрических влагомеров возможностью измерени влажности веществ с большими диэлектрическими потер ми и независимостью результатов измерени от величины этих потерь.The closest technical solution to the invention is a moisture meter containing a capacitive primary transducer, a measuring two-port device with modulated parameters, a high-frequency generator, a modulator, a zero-organ and a balancing body 3. This moisture meter is profitable: but differs from other known dielectric moisture meters in measuring moisture substances with high dielectric losses and independence of measurement results on the magnitude of these losses.

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Но это устройство также представл ет результаты измерений не в единицах влажности, а в виде частоты, и влажность наход т по индивидуальной градуировочной зависимости дл каж5 дого материала.But this device also presents the results of measurements not in terms of moisture, but in the form of frequency, and the humidity is determined by an individual calibration dependence for each material.

Цель изобретени - получение результатов измерени непосредственно в процентах влажности материала без использовани в процессе изме0 рений градуировочных зависимостей.The purpose of the invention is to obtain measurement results directly in percent of the moisture content of a material without using calibration dependencies in the measurement process.

Указанна цель достигаетс за счет введени в известный влагомер преобразовател частоты в количество импульсов с переменным масштабом . This goal is achieved by introducing a frequency converter into a number of pulses with a variable scale into a known moisture meter.

Claims

5 conversion, pulse generator with adjustable frequency, control circuit, reversible pulse counter and digital display unit. At the same time, the output of the high-frequency generator is connected to the input of a frequency converter, the output of which is connected to one of the inputs of the control circuit, to the other input of which is connected the output of the pulse generator with an adjustable follow frequency. The output of the control circuit is connected to a reversible counter, the output of which is connected to a digital display unit. The drawing shows a structural diagram of an automatic electronic moisture meter. The moisture meter contains a capacitive primary transducer 1, a measuring two-pole 2, a high-frequency generator 3, a modulator 4, a zero-body 5, a balancing body 6, a frequency converter 7 to the number of pulses with a variable conversion head, a control circuit 4, a generator of 8 square-wave pulses with adjustable tracking frequency, control circuit 9, reversible pulse counter 10 and digital display unit 11. The moisture meter works as follows. The frequency of the high-frequency generator 3 pulses, which is a measure of humidity, in converter 7, the conversion scale of which is set during the initial adjustment of the moisture meter, is converted into a specific number of pulses that through the control circuit 9 arrive at the input of the reversible pulse counter 10 (addition). Then the control circuit thematically turns off the output of the converter 7 from the counter input and connects the generator output 8 (subtraction) to it for a certain time. The difference in the number of pulses received in the counter in the modes of addition and subtraction is numerically equal to the value of the measured humidity, is recorded in the digital display unit 11. The initial setting of the moisture meter is as follows. The generator 8 is disconnected from the control circuit 9. Two samples of this material are taken, one of which is dried to a constant weight, and the other has exactly known humidity. Alternately, the capacitive primary transducer is applied to the dry and wet samples and following the digital indicator while setting the conversion scale so that the difference between the readings corresponding to the wet and dry samples is set equal to the value of the known humidity. 24 After this, the generator 8 is turned on and, by applying the sensor to a dry sample, adjust the pulse frequency of the generator 8 so that zero is set on the digital indicator. This completes the setup and the moisture meter is ready for operation. Using the described invention will allow you to automatically receive measurement results directly from B percent moisture, which is especially important for automated control systems for various technological processes. The ease of restructuring the described moisture meter for various materials and the absence of the need for a large number of different calibrations, which are long and laborious operations 1I, ensure its versatility and high metrological characteristics. Claims of the invention An automatic electronic moisture meter containing a primary capacitive transducer, a two-terminal measuring cell with modulated parameters, a high frequency generator, a modulator, a zero body and a balancing body, characterized in that, in order to obtain measurement results directly in percent of humidity, a converter is additionally introduced into it. frequency in the number of pulses with a variable conversion scale, pulse generator with adjustable tracking frequency, control circuit, reversing A pulse counter and a digital display unit, with a high-frequency generator connected to the input of a frequency converter, the output of which is connected to one of the inputs of the control circuit, to another input of which the output of the pulse generator is connected, with an adjustable tracking frequency, the output of the control circuit is connected to a reversible counter whose output is connected to the digital display unit. Sources of information taken into account during the examination 1.Berliner MA, Moisture Measurements, M., Energie, 1973, p.112.

2. The measuring technique, 1976, No. 7, p.74.

3. Author's certificate Oh, cl. C 01 N 27/22, 1973 (prototype).