จำนวน Repository ( 17 )

The innovation construction for the toughness measurement of rice kernel with the inner pressure method
The innovation construction for the toughness measurement of rice kernel with the inner pressure method

During the rice processing the possible situations of rice kernel cracking and breakage are commonly occurred and these consequences cause a low marketing price. According to this issue the real-time observation and together with the knowledge base of mechanical properties should be essentially helpful in detection of these defect observations. The objective of this work was established to study the mechanical stress-strain properties of rice kernels via our in-house pneumatic system design. We found that stress-strain of RD6 RD15 Phitsanulok 2 and Khao Dawk Mali 105 were greater than KhaoYipun DOAI with moisture content of 20% w.b. These results tentatively indicated the mechanical stress-strains occurred were from the difference of rice shapes. Moreover we could recognize that the characteristics of these various shapes significantly followed the scaling law of the relation between strain and time. We also found that the breaking force was different value for rice varieties. This parameter obtained can be such a high potential approach that can be used for further developing in the quantitative classification of rice varieties.

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High Current Measurement Method by Means of Rogowski Coil Maximum 1kA
High Current Measurement Method by Means of Rogowski Coil Maximum 1kA

Nowadays electrical current measurements can be categorized into two methods; direct and indirect measurements. The small amount of electrical current can be directly measured by means of electrical current instrument whereas the current of high voltage cannot directly be measured by means of any physical contact of an instrument on the other hand it can be indirectly be measured through voltage transformer by stepping down voltage method in which cannot be realized economically and practically. This paper presents a method of measuring high voltage current by means of Rogowski coil detecting induced electromagnetic ware compensating unwanted induced current and finally amplifying. The results are that the reduction of measurement time and cost of purchasing the instrument.

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A Microstrip Folded Resonator Sensor for Measurement of Dielectric Constant
A Microstrip Folded Resonator Sensor for Measurement of Dielectric Constant

A microstrip folded ring resonator sensor for measurement of dielectric constant in a compact area of material under test is proposed. The resonant characteristics of resonator vary with dielectric constant of material. Limitations in the microwave frequency response performances of the proposed sensor have been carefully studied in a range from 500 MHz to 3 GHz. It has been found that the proposed sensor has great potentials for practical applications in view of low cost and monolithic integration capability with a driving circuit.

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ผลของอุณหภูมิที่มีต่อค่าความต้านทานและความจุไฟฟ้าของข้าวเปลือกที่มีความชื้นแตกต่างกัน
ผลของอุณหภูมิที่มีต่อค่าความต้านทานและความจุไฟฟ้าของข้าวเปลือกที่มีความชื้นแตกต่างกัน

This research proposes an application of resistive and capacitive soil moisture sensors to investigate the influences of paddy temperature on the electrical signal received from sensors when tested with paddy moisture in the range 9.2 - 22.75%wb at 40 - 80ºC to determine the relationship between paddy moisture and electrical signals. It was found that the mean signal values between 20 - 40 seconds from both sensors were inversely linear correlation with the moisture content of the paddy. Temperature is the factors that influence the measured electrical signal. R2 Adjust R2 (95% confidence interval) and RMSEC showed that the model developed from the resistive sensor signals was accurate in calculating the moisture content of paddy between medium to high temperature in range 60 - 80ºC more than the low temperature range. While the capacitive sensor signals model is accurate in calculating paddy moisture between low to medium temperature in range 40 - 60 ºC. Therefore the resistive soil moisture sensor is possible and more suitable for applying as a paddy moisture sensor in the high temperature drying processes than a capacitor soil moisture sensor.

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การศึกษาผลกระทบของขนาดโหลดเซลล์ที่ส่งผลต่อค่าความคลาดเคลื่อน
การศึกษาผลกระทบของขนาดโหลดเซลล์ที่ส่งผลต่อค่าความคลาดเคลื่อน

The objectives of this research is to study the relationship between tolerance and measurement range of load cells. Tolerance test kit length of mass beam 90 cm was used. It can create the compressed force at the load cell more than 1 kN. The experiment cam be divided into 2 stages; 1.) verification of load range and 2.) linearity test. Both stages are tested at a temperature at 25°C using 10 to 30 kg of mass in the lowest compressed force condition of 0.091 kN and the maximum compressed force condition of 1.12kN As a result the linearity performance of the tolerance of the load cell test kit between calculated force and displayed value force are different 0.354 percentage only while the standard deviation of displayed value force and voltage signal output are 0.0013 and 0.0022 respectively. It reveals that the experimental result is reliable because of less than 1. In addition the tolerance of the load cell tolerance testing machine is 0.00300 (0.3 percent) which was calculated from the comparison of the tolerance specification of two main equipment that specified by manufacturer.

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