SU1173283A2 - Method of determining relative humidity of disperse materials - Google Patents

Abstract

METHOD FOR DETERMINING THE RELATIVE HUMIDITY OF DISPERSED MATERIALS by auth.St. P 1002929, characterized in that, in order to improve measurement accuracy by eliminating the influence of the granule size on the beginning of the dehydration process under ultrasonic action, after the measurement of humidity has been completed, a second measurement is made at a specified time interval at the beginning of the dehydration process, and The value sought is determined by the difference in measurement.

Description

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The invention relates to a measurement technique, can be used for the rapid analysis of the moisture content of bulk materials, in particular, grain and products of its processing, and is an improvement of the method according to the author. No. 1002929.

The aim of the invention is to improve the measurement accuracy by eliminating the influence of the size of the granules on the beginning of the dehydration process under ultrasonic action.

Fig. 1 shows a block diagram of a device for carrying out the method of the invention; Fig. 2 shows the timing of the diagram explaining the method. The block diagram contains a vacuum pump 1, an electric vacuum valve .2, a measuring chamber 3, a dielectric meter 4, a cuvette 5 for a sample of dispersed material, an ultrasonic transducer 6, a generator. 7 e; ktricheskikh fluctuations, power supply unit 8. In addition, a device for storing the first and second measurements, a device 10 for subtracting measurement results, a humidity measurement indicator 11 and a pressure indicator 12 in the measuring chamber, are entered in the flowchart. . The method is carried out as follows. In the cuvette 5 poured the test material. Place the cuvette with the test material in the measuring chamber 3 and close it, open the vacuum valve 2 and turn on the vacuum pump 1. After reaching the required degree of vacuum in the measuring chamber, as judged by the pressure indicator 12, close the vacuum valve and turn off the vacuum pump. Include generator 7 electrical oscillations. The process of increasing the amplitude of vibrations by ultrasonic transform. Summoner 6 occurs relatively quickly. It can be considered that in 1-2 s after switching on the generator of electrical oscillations the process of uniform dehydration of moisture from the sample is established. Therefore, 2 seconds after switching on the generator of electrical oscillations, the readings of the dielcometer 4 are measured. The measurement value is transferred to the memory of the memory device 9.

After a predetermined time interval, for example 10 seconds, the second meter readings are measured. The value of this measurement also enters the device 9. After the second measurement is finished, the results of the first and second measurements go to the subtraction device 10, and from there to the humidity indicator 11,

Since the dehydration rate after the start of the drying process is constant, and the measurement time (interval from tJ to C) is much less than the time required to dry the sample, we can assume that the lines A, B and C (Fig 2) are straight and parallel have the same inclination to the x-axis. From the equality of triangles 1–4–9, 2–5–3, 3–6–7, it can be seen that, irrespective of the magnitude of P, the ordinates 1–4, 2–5, 3–6 are equal to each other, i.e. to the same time T, ea always corresponds to the same value of the increment of the mass of moisture in the measuring chamber. By calibrating the dependence of the increment m T, it is possible to predict with a high degree of accuracy the relative humidity for another similar sample of this material. The error in the implementation of the proposed method is expressed by the dependence, where A | - the error consisting of the calibration error d, and the error L, determined by the measurement instability, ij is the measurement error of the diel meter. Simple calculations show that the use of the frequency-pulse method of measuring capacitance with an indication in the form of a digital value code and. and D- is not more than 0.01% of the measured value.

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Claims (1)

METHOD FOR DETERMINING RELATIVE HUMIDITY OF DISPERSED ALA by auth. No. 1002929, which means that, with ‘increasing the accuracy of measurements, eliminating the influence of the size of the granules on the beginning of the dehydration process under ultrasonic treatment, at the end of the moisture measurement for a certain period of time at the beginning of the dehydration process, SO y 00 00