SU1195244A1 - Arrangement for measuring parameters of textile materials - Google Patents

Description

The invention relates to the textile industry, namely, devices for measuring parameters of textile materials such as linear density, humidity, etc.

The purpose of the invention is to improve the measurement accuracy by reducing the error of instability in time of the parameters of the elements of the device.

Figure 1 shows the block diagram of the proposed device; figure 2 timing diagrams of the keys.

The device contains a generator of 1 high-frequency oscillations and generation. torus 2 low-frequency oscillations through the keys 3 and 4 connected to one of the plates of a capacitive sensor 5 of the material parameter and the reference capacitor 6, the other plates of which through the keys 7 and 8 are connected to a series-connected amplifier 9, demodulator 10, analog-to-digital converter (ADC) 11 and computational unit 12. Direct and inverse outputs of the unit 13 synchronization operation of keys (BSRK) connected to the control inputs of the ADC 11. The input of the frequency divider 14 two connected to one of the outputs BSRK К 13, and the direct and inverse outputs of the divider "1 4 are connected to the control inputs of keys 7 and 8. Generators; 1 and 2 high-frequency and low-frequency oscillations are assembled by inductive

© three-point scheme. The frequency of the generator is 1-10 MHz, the generator is 2 1 MHz.

The device works as follows.

The generator 1 of high-frequency oscillations produces harmonic oscillations of a sinusoidal form with a voltage U, and a frequency I ,. Accordingly, the generator 2 produces a voltage signal of 0 ₂ and the frequency ί _ζ. Through analog switches 3 and 4, which work in antiphase, the outputs of the generators 1 and? alternately connected to the reference capacitor 6 and the capacitive sensor 5. The keys 7 and 8 are working in antiphase with chas- ⁴ totoy twice smaller than the keys 3 and 4. The signal across the keys 7 and 8

arrives at the amplifier 9, the demodulator 10 and the ADC 11. Thus, in accordance with the operation diagram of the keys (FIG. 2), four voltage values in the digital code are output at the output of the ADC 11

) ^and cs £ g 1

ten

' ^g d ^e c _{co £} ,

cl £ g

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spz £ 1

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C3 {2

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a voltage value proportional to the capacitance of the sensor for often ^those ;

voltage value proportional to the capacitance of the sensor at a frequency of £ _g ;

voltage value proportional to the capacitance of the reference capacitor at frequency 1,) voltage value proportional to the capacitance of the reference capacitor at a frequency of 1 _g .

The measured digital voltage values are stored in the memory of the computing unit 12, and then processed.

To determine the capacitance Cd sensor at frequencies частот ₁ and.

accordingly it is necessary to make the following calculations:

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NE £ 1

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se £ 1

CB12

Wed £ 2

- _{ee 5}

40 where C _e - the capacitance value of the reference capacitor,

K - scale factor. One possible algorithm

- the increments of the capacitance of the sensor A characterizing the value of the monitored parameter are as follows:

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where is the LS _P £ are the changes of the sensor's bones at frequencies ί, and ί. ₂ respectively.

1195244

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1195244

Claims (1)

A device for measuring parameters of textile materials, mainly linear density, containing generators of high-frequency and low-frequency oscillations, outputs connected to the inputs of the first and second keys, the control inputs of which are connected to the corresponding mutually inverted outputs of the synchronization unit of the keys, and the outputs of the keys are combined and connected to the capacitive inputs sensor parameter of the material and the reference capacitor, the third and fourth keys, amplifier and demodulator, the output associated with you An ultrasound unit, characterized in that, in order to improve measurement accuracy by reducing the error of instability in time parameters of the device elements, it is equipped with a frequency divider by two, the input of which is connected to one of the outputs of the key synchronization unit, and mutually inverse outputs of the frequency divider by two connected to the control inputs of the third and fourth keys, respectively, the outputs of which are combined and connected through an amplifier to the input of the demodulator, and the output of the capacitive sensor parameter material and reference capacitor are connected to inputs of the third and fourth keys respectively, wherein the outputs of the synchronization block of keys connected to the control inputs of the analog-to-digital converter computing unit. $ Ц 1195244 > 1 1195244>