SU1453298A1 - Device for measuring humidity of loose materials - Google Patents

Abstract

The invention relates to a measurement technique and can be used to measure the moisture content of bulk materials. The purpose of the invention is to improve the measurement accuracy. A device for measuring humidity contains a measuring device, a sensor made of two tubes of different lengths, with measuring and auxiliary electrodes placed at the end of a long tube. Inside the short tube moving along the long one there is an elastic element, and on the surface of both tubes there are contact rings connected to the measuring circuit. Accuracy is achieved by measuring with a normalized seal and directly in the seal zone. 1 il. i (L

Description

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The invention relates to a measurement technique, namely to the dielectricity of bulk materials, and can - find application in measuring humidity, for example, refractory materials and grain by the express method in laboratory, shop and field conditions in the range of humidity changes from 0-30 %

The purpose of the invention is to improve the measurement accuracy.

The drawing shows a constructive capacitive sensor and an electrical circuit of the device.

A device for measuring the humidity of bulk materials includes a measuring device 1, a capacitive sensor 2, a coaxial cable 3. Measuring device 1 includes a DENSITY indicator and a moisture meter IV, Density indicator includes a series-connected power source E, an LED LED and a resistor R. The moisture meter is a high-frequency pulsed resonant generator, switched on by Euodus from the arms of the potentiometric bridge, the other arm includes the elements of the balance setting, and iagonal measuring device, e.g. a micro-ammeter. The capacitive sensor 2 includes a long metal tube 4, a shortened metal tube 5, a measuring 6 and an auxiliary 7 electrodes, a capacitor 8, a metal contact ring 9, a conductor 10, an elastic element 11. The shortened tube 5 is mounted on the upper part of a long tube 4 coaxially with it with a gap and with the possibility of movement against the stop with a contact metal ring 9. The ring -9 is rigidly fixed by means of an insulator 12 on a long tube 4. One end of the conductor 10 is connected to the metal ring 9. Electrodes 6 and 7 are mescheny coaxially with the tube 4. Vspomogatelnsh electro 7 is formed as a flat washer and fixed to the lower end of a long metal tube 4. The measuring electrode 6 is formed as a flat disc, is located outside the tube 4 to the dielectric gap. However, the plate 13 of the condenser 8 is connected to the core 14. cable 3. The second plate 15 of the capacitor 8 is connected to the measuring electrode 6. The screen 16 of the cable 3 is internally connected to a long metal tube 4. The cable 3 is passed through a hole in the insulator 12 and the tube 4. Conductor 10 is protected by an insulating braid and wound onto a coaxial cable 3. The second end of the conductor 10 is connected to the positive pole of the power source E. Screen 16 of the cable 3 is connected to the resistor R and the input of the moisture meter. The output of the moisture meter is connected to the conductor 14 of cable 3. Such a connection can be provided with a connector.

The device works as follows.

Capacitive sensor 2 end part immersed in the analyzed material. Compaction is provided by pressing the shortened metal tube 5, which moves, compressing the elastic element 11, relative to the long tube 4 against the stop with the contact metal ring 9, as a result of which the electrical density indicator circuit is closed, as judged by the LED. After turning on the LED, the immersion of the capacitive sensor 2 is stopped. The density indicator triggers under the condition that the force applied to the pipe 5 becomes greater than the resistance force of the elastic element 11. After the bulk material, located in the electrode zone of the electrodes 6 and 7, is compacted to a certain value, the humidity of this volume is measured. of a bulk material with a moisture meter based on a change in the current balance of a high-frequency pulsed resonant oscillator circuit, which occurs when the generation frequency varies, depending on the dielectric parameters of the analyzer direct the bulk material in the measurement zone. Changes in the current balance are monitored by a microammeter included in the moisture meter.

Microammeter readings corresponding to specific moisture values are used to determine the absolute moisture values of the bulk material from the calibration graphs or tables for this material at appropriate values

Editor L.Zaytseva

Compiled by V.Nemtsev

Tehred M. Didyk Proofreader O. Kravtsov

Order 7277/40

Circulation 788

VNIIPI State Committee for Inventions and Discoveries at the State Committee on Science and Technology of the USSR 113035, Moscow, Zh-35, Raushsk nab. 4/5

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Claims (1)

Claim . A device for measuring the moisture content of bulk materials, comprising a measuring device and a capacitive sensor connected to it, made in the form of two metal tubes of different lengths with a measuring and auxiliary electrodes ₅ located in the lower part of the long tube and a capacitor located inside the tube, one about -., the masonry of which is connected to the measuring circuit, characterized in that, in order to increase the accuracy of measurement 10, the specified auxiliary electrode is fixed to the end of the tube, will measure flax electrode protrudes from the end of the tube with dielectric gap and is connected to another 15 with a condenser lining, a shortened tube is mounted on the upper part of a long tube coaxially with it with a gap and with the possibility of moving to the stop with a contact metal ring rigidly fixed by means of an insulator on a long tube, electrically connected to the measuring circuit.