• Journal of Industrial Technology
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• v.15
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• pp.83-91
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• 1995

This paper presents the design of a smart A/D conversion interface used for measuring the load of a truck. Since the load-cell sensor to be used is very sensitive for weight variation, the interface board must have the low-drift and the A/D conversion for accuracy. A new integrator and comparator has been developed to reduce the offset voltage and the drift current of operational amplifiers and has been adapted into the interface board. Also, a software algorithm has been developed to obtain the stable and accrurate A/D conversion. This software includes a RS-485 communication program to control the interface, which gives a capability of backing-up the calibration data and transferring control data. The test and evaluation of the designed interface has been shown as having the better performance compared to the other types of existing weighing systems and sensor instruments.

• Journal of Sensor Science and Technology
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• v.14 no.4
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• pp.237-243
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• 2005

Strain gauge type load cell is used widely as weight sensor. However, it has problems such as noise, power consumption, high cost and big size. Semiconductor type piezoresistive pressure sensor is practically used in recent for low hysteresis, good linearity, small size, light weight and strong on vibration. In this paper, we have fabricated the piezoresistive pressure sensor and packaged the miniature weight sensor. We packaged the miniature weight sensor by flip-chip bonding between die and PCB for durability, because the weight sensor is directly contacted on a physical solid distinct from air and oil pressure. We measured the characteristics of the weight sensor, which had the output of $10{\sim}80$ mV on the weight range of $0{\sim}2$ kg. In the result, we could fabricate the weight sensor with an accuracy of 3 %FSO linearity.

• Proceedings of the KIEE Conference
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• 1993.07b
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• pp.1298-1300
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• 1993

Compensation of temperature is very important to make high precision Load Cell. In this study, we developed a new type of load cell. The structure of the load cell has four strain gauges m single surface of the load cell. Also a new temperature compensation method is proposed and these, characteristics are better than previous one. This study will offer application to other type of load cell end another sensors.

• The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.11 no.1
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• pp.114-122
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• 1997

This paper describes the design and development of a smart digital load cell used forweighing installations. Sice the load cell sensor to be used is very sensitive for weight cariation, the load cell must have the temperature stability, low-drift and the high-resolution of the A/D conversion for accuracy. A new analog circuit which is controlled by one chip micro-processer has been developed to reduce the offset voltage and the drift characteristics of operational amplifiers, and has been adapted into the digital load cell. Also, a software algorithm has been developed to obtain the stable and accurate A/D conversion. This software includes a RS-485 communication program to control the digital load cell, which gives a capability of backing-up the calibration data and transferring control data. The simulation and evaluation of the designed digital load cell has been shown as having the good performance. which will give useful application to the weighing installations as a remote weighing sensor.

• Journal of the Korea institute for structural maintenance and inspection
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• v.23 no.2
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• pp.130-134
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• 2019

In this paper, a laser-based non-contact load cell is newly developed for measuring forces in prestressed concrete tendons. First, alumina particles have been sprayed onto an empty load cell which has no strain gauges on it, and the layer has been used as a passive stress sensor. Then, the spectral shifts in fluorescence spectroscopy have been measured using a laser-based spectroscopic system under various force levels, and it has been found that the relation of applied force and spectral shift is linear in a lab-scale test. To validate the field applicability of the customized load cell, a full-scale prestressed concrete specimen has been constructed in a yard. During the field test, it was, however, found that the coating surface has irregular stress distribution. Therefore, the location of a probe has to be fixed onto the customized load cell for using the coating layer as a passive stress sensor. So, a prototype customized load cell has been manufactured, which consists of a probe mount on its casing. Then, by performing lab-scale uniaxial compression tests with the prototype load cell, a linear relation between compression stress and spectrum shift at a specific point where laser light had been illuminated has been detected. Thus, it has a high possibility to use the prototype load cell as a force sensor of prestressed concrete tendons.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2020.11a
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• pp.186-187
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• 2020

Damage to temporary facilities and structural members caused by excessive loads in the field continue to occur. If the load can be monitored in advance, the risk can be prevented. In this study, a load cell sensor is installed under the system support, and load data is wirelessly transmitted through a Bluetooth AP(wireless). Risk prediction system is proposed through an construction alarm when an abnormal load occurs through real-time multi-point monitoring by sensor location.

• Journal of the Korean Society for Nondestructive Testing
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• v.29 no.4
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• pp.299-307
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• 2009

Emerging fiber optic sensor technologies have shown great potential to overcome the difficulties associated with conventional sensors. Fiber optic sensors are immune to EM noise and electric shock and thus can be used in explosion-prone areas. Several kinds of fiber optic sensors have been developed over the last two decades to take advantage of these merits. There have also been many field applications of fiber optic sensors for structural health monitoring as NDT/HDE. However, very few sensors, particularly a load cell have been successfully commercialized. This Paper Presents a load cell using fiber Bra99 gra1ing (FBG) sensors. The shape of the load cell is a link type, and three FBG sensors are used for measuring strains at three different points. Especially, these strains are processed with a differential method in order to exclude common mode noise such as temperature. Moreover, the sensitivity, the linearity and the resolution of the load cell were successfully verified from the experiment of tension test.

• Journal of the Korean Geotechnical Society
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• v.27 no.6
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• pp.17-26
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• 2011

Ground anchor method is one of the most popular reinforcing technology in Korea. For the sound monitoring of slope reinforced by permanent anchor for a long period, monitoring the tension force of ground anchor is very important. However, special technology except conventional load cell has not been developed for this purpose. In this paper, a new method is described to replace the conventional strain gauge and V.W. type load cell which has been commonly used as a prestress force monitoring tool for a short-term and long-term. Four 11.5 m long strain detectable tension type anchors were made using FBG sensor embedded tendon since FBG sensor is smaller than strain gauge type load cell and does not have noise from electromagnetic wave. Each two set strain detectable tension type anchors were installed into the different ground conditions, i.e., soft rock and weathered granite soil. Prestress force of ground anchor was monitored during the loading-unloading step from in-situ pullout test using proposed FBG sensor embedded in the tendon and the conventional load cell Test results show that the prestress force monitored from FBG sensor may well be used practically, for it almost matches with that measured from expensive load cell.

• Journal of Drive and Control
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• v.17 no.4
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• pp.97-102
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• 2020

This paper presents the basic research for the design and fabrication of a 3D-printed load cell made of NCPC (nano-carbon piezo-resistive composite). We designed a structure that can resonate at a low frequency range of about 5-6 Hz with ANSYS using sensitivity analysis and a response surface method. The design was verified by fabricating the device with a low-quality commercial 3D printer and ABS filament. We conducted a feasibility test for a commercial sensor using 1000 cyclic load tests at 0.3 Hz in a material testing system. A manufacturing process for the 3D printer filament based on the NCPC was also developed using the nano-composite process.

• International Journal of Precision Engineering and Manufacturing
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• v.1 no.1
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• pp.22-32
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• 2000

This paper describes the development of a precision 3-component load cell with plate beams which may be used for measuring forces Fx, Fy and moment Mz simultaneously in industry. The equations to predict the bending strains on the surface of the beams under forces or moment are derived, the attachment location of strain gages of each sensor is determined, and 3-component load cell is carried out. It reveals that the rated strain calculated from the derived equations are good agreement with the results from Finite Element Method analysis.