SU1075127A1 - Device for measuring material humidity - Google Patents

Description

The invention relates to microwave moisture metering technology and can be used in determining the moisture content of agricultural products, food industry, raw materials and materials of light industry, in construction, as well as in various areas of industrial production.

A device is known for detecting humidity in various fluxes, including an electromagnetic oscillator connected to a drying chamber mounted on electronic scales, the output of which is connected to an indicator U

A disadvantage of the known device is that, for example, drying organic material, loss of hygroscopic moisture results in loss of volatile components, and sometimes thermal dissociation of the sample, which leads to methodological errors in determining humidity.

The closest to the technical essence of the invention is a device for measuring the moisture content of materials containing an electromagnetic oscillator connected to a drying chamber that is mounted on an electronic scale, while the output of electronic scales is connected to the first input of a microprocessor with an analog-digital converter, at the output of which the indicator is turned on, and the output of the control signal is connected to the control input of the generator of the 1ag oscillations of the 2j oscillator.

However, the known device for measuring the moisture of materials has a low accuracy of measurements, since it is not the residual moisture of the material.

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

The goal is achieved by the fact that in a device for measuring the humidity of materials, containing an electromagnetic oscillator, connected to a drying chamber that is mounted on electronic scales, the output of electronic scales is connected to the first input of a microprocessor with an analog-digital converter, the output of which is an indicator and the output of the control signal is connected to the control input of the generator of electromagnetic oscillations, the drying chamber is provided with electrodes of an introduced dielectric converter The output of which is connected to the second input of the microprocessor with an analog-digital converter, to the third input of which the output of the input software switch is connected.

In this case, the drying chamber is equipped with a temperature meter of the material under study, the output of which is connected ti to the fourth input of the microprocessor with the analog-digital converter.

The drawing shows the structural electrical circuit of the device for measuring the humidity of materials.

The device contains a generator 1

electromagnetic oscillations, drying chamber 2, installed by me; with electrodes of dielectric converter 3, temperature meter 4, electronic scale 5,

5, a microprocessor 6 with an A / D converter 7, a program switch 8, an indicator 9. A device for measuring the humidity of materials operates as follows.

Q program switch 8

the residual moisture value optimal for this material is stopped (for example, 5% for grain |. The material is placed in a drying chamber 2. The initial weight of the material Pd is measured by an electronic scale 5, encoded and stored in the microprocessor storage unit B. By program / item - / 1e microprocessor b

Q generates a drying start command and transmits it to the control element of generator 1 and performs drying. Data on the temperature of the material in the drying process, obtained with

using a temperature meter 4, enter microprocessor b, which regulates the average power of generator 1, keeping the temperature of the material constant.

The dielometric converter 3 produces an electrical signal proportional to the moisture content of the material. This signal is processed by microprocessor b. When the residual moisture V / f is reached, microprocessor 6 turns off the generator 1 and stops drying. The final weight of the material Pj / is measured by an electronic balance 5, encoded in an analog-to-digital converter 7 and the microprocessor 6 calculates the measured humidity using the formula

- R,

V

100 + VV.

The result of the calculation of humidity is displayed by indicator 9. The dependence of the residual moisture on time

Drying can be divided into two time sections: ti and t2 Time 12 is associated with drying of bound water. Moreover, the time 1 is several times less than the time ti, the drying time in this

device corresponds to the time if. Thus, the proposed device, in which the assembly is carried out. The two methods of measuring humidity allow to increase the speed of thermogravimetric installations, since it eliminates the need for drying. In addition, drying in this device is carried out at a constant temperature. This eliminates one of the main reasons affecting the accuracy of dielectric moisture meters - temperature instability. Since the material is dried before the measurement with the dielectric moisture meter, its resistance increases. Those cat. another source of error of the dielectric moisture meter is eliminated. Residual moisture is determined by e-. with only one point. All the listed circumstances provide high accuracy in determining the total humidity inherent in thermogravimetric installations.

Claims (2)

1. DEVICE FOR MEASURING THE HUMIDITY OF MATERIALS, comprising an electromagnetic oscillation generator connected to a drying chamber mounted on an electronic balance, the output of the electronic balance being connected to the first input of the microprocessor with an analog-to-digital converter, the output of which JV> the indicator is turned on, and the control signal output is connected to the control input of the electromagnetic oscillation generator, characterized in that, in order to increase the measurement accuracy, the drying chamber is equipped with electrodes of the introduced dielectric transducer, the output of which is connected to the second input of the microprocessor with an analog-digital converter, to the third whose input is connected to the output of the entered software switch. 2. The device according to claim 1, characterized in that the drying chamber is equipped with a temperature meter for the test material, the output of which is connected to the fourth input of the microprocessor with an analog-to-digital converter. SU ... 107