• Structural Monitoring and Maintenance
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• v.3 no.4
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• pp.335-347
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• 2016

One of major errors in flow rate measurement for two-phase flow using an Electrical Capacitance Sensor (ECS) concerns sensor sensitivity under temperature raise. The thermal effect on electrical capacitance sensor (ECS) system for air-water two-phase flow monitoring include sensor sensitivity, capacitance measurements, capacitance change and node potential distribution is reported in this paper. The rules of 12-electrode sensor parameters such as capacitance, capacitance change, and change rate of capacitance and sensitivity map the basis of Air-water two-phase flow permittivity distribution and temperature raise are discussed by ANSYS and MATLAB, which are combined to simulate sensor characteristic. The cross-sectional void fraction as a function of temperature is determined from the scripting capabilities in ANSYS simulation. The results show that the temperature raise had a detrimental effect on the electrodes sensitivity and sensitive domain of electrodes. The FE results are in excellent agreement with an experimental result available in the literature, thus validating the accuracy and reliability of the proposed flow rate measurement system.

• Journal of Electrical Engineering and Technology
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• v.12 no.2
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• pp.904-910
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• 2017

This paper presents temperature measurement of solar photovoltaic modules using the custom-made system composed of an infrared temperature sensor and a microcontroller. The obtained measurement results are processed, displayed and stored on a PC using the custom-made virtual instrument. The proposed system overcomes some of the problems related to the contact sensor application, and at the same time offers accurate readings and better flexibility. The proposed system is especially suitable for applications where the cost is a limiting factor in the choice of measuring system. The conducted analysis and the obtained results have shown an excellent accuracy of the proposed system in comparison to a high quality thermal imaging camera used as the reference instrument.

• Journal of Advanced Navigation Technology
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• v.27 no.4
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• pp.469-472
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• 2023

If temperature management is required in factory or environmental monitoring, temperature can be measured by connecting various sensors wired or wirelessly. Surface acoustic wave sensors measure temperature using changes in acoustic waves on the sensor surface according to temperature, and are useful for wireless networks. In this paper, in order to build a wireless temperature measurement system in the 900 MHz frequency band, the temperature characteristics of the passive SAW sensor were measured, and the analysis and removal of multipath reflection wave effect inside the high temperature chamber were conducted. The resonant frequency of the SAW sensor was measured, and radio transmission/reception and multipath reflected wave removal techniques were proposed in the shielded chamber.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.9
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• pp.2087-2092
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• 2015

Recently, use of the heat transferring machine and systems has been increasing in various industrial fields. A key technique for constructing such process is basically to measuring temperature directly to objects established on industrial plants. Particularly, a non-contact temperature measurement is very important to realize advanced heat transferring systems. This paper presents a new measurement methodology for temperature by using USN(ubiquitous sensor networks) technique including the microprocessor unit based ZigBee communication systems. This proposed system is made to be applied in monitoring systems for non-contact temperature measurement. We designed firmware based measurement systems whose main function is to save s series of temperature data sets and send it to main monitoring systems.

• Journal of Sensor Science and Technology
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• v.27 no.5
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• pp.300-305
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• 2018

The uncooled microbolometer thermal sensor for low cost and mass volume was designed to target the new infrared market that includes smart device, automotive, energy management, and so on. The microbolometer sensor features 80x60 pixels low-resolution format and enables the use of wafer-level vacuum packaging (WLVP) technology. Read-out IC (ROIC) implements infrared signal detection and offset correction for fixed pattern noise (FPN) using an internal digital to analog convertor (DAC) value control function. A reliable WLVP thermal sensor was obtained with the design of lid wafer, the formation of Au80%wtSn20% eutectic solder, outgassing control and wafer to wafer bonding condition. The measurement of thermal conductance enables us to inspect the internal atmosphere condition of WLVP microbolometer sensor. The difference between the measurement value and design one is $3.6{\times}10-9$ [W/K] which indicates that thermal loss is mainly on account of floating legs. The mean time to failure (MTTF) of a WLVP thermal sensor is estimated to be about 10.2 years with a confidence level of 95 %. Reliability tests such as high temperature/low temperature, bump, vibration, etc. were also conducted. Devices were found to work properly after accelerated stress tests. A thermal camera with visible camera was developed. The thermal camera is available for non-contact temperature measurement providing an image that merged the thermal image and the visible image.

• Journal of Korea Society of Digital Industry and Information Management
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• v.7 no.1
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• pp.1-9
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• 2011

In this paper, Wireless sensor network technology applied to various greenhouse agro-industry items such as horticulture and local specialty etc., we was constructed automatic control system for optimum growth environment by measuring growth status and environmental change. existing monitoring systems of greenhouse gather information about growth environment depends on the temperature. but in this system, Can be efficient collection and control of information to construct wireless sensor network by growth measurement sensor and environment monitoring sensor inside of the greenhouse. The system is consists of sensor manager for information processing, an environment database that stores information collected from sensors, the GUI of show the greenhouse status, it gather soil and environment information to soil and environment(including weather) sensors, growth measurement sensor. In addition to support that soil information service shows the temperature, moisture, EC, ph of soil to user through the interaction of obtained data and Complex Growth Environment information service for quality and productivity can prevention and response by growth disease or disaster of greenhouse agro-industry items how temperature, humidity, illumination acquiring informationin greenhouse(strawberry, ginseng). To verify the executability of the system, constructing the complex growth environment measurement system using wireless sensor network in greenhouse and we confirmed that it is can provide our optimized growth environment information.

• Journal of Sensor Science and Technology
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• v.28 no.3
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• pp.177-181
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• 2019

Pressure sensors are used in various industries such as automobiles, airplanes, medical equipment, and coolers. Even if the ambient temperature changes, the measurement is reliable and stable. In this study a diaphragm-type pressure sensor was used to derive a temperature-compensated pressure estimation equation for accurate pressure measurement at $100^{\circ}C$ and $-40^{\circ}C$. To understand the characteristics of the pressure sensor diaphragm with respect to temperature and pressure, experiments were conducted in temperature-variable chamber using FEM analysis to confirm that the influence of temperature effect was nonlinear. Based on the experimental results, a nonlinear method for calculating the pressure by compensating for the error due to temperature was derived. The calculated pressure value is lower than 0.5 % at low and high temperatures, and lower than 0.4 % at $22^{\circ}C$, thereby eliminating the effect of temperature.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.5
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• pp.1730-1734
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• 2010

Generally, a pH value of secondary water in a nuclear power plant should be estimated after sampling and cooling down. In this process, the measurement of temperature is very important because a pH value is varied according to the temperature of secondary water. In this study, a noncontact fiber-optic temperature sensor using a silver halide optical fiber is fabricated to measure the temperature of cooled secondary water. And we have measured an infrared radiation, which is transferred by a silver halide optical fiber from a heat source, using a thermopile sensor. The relationships between the temperature of a heat source and the output voltage of the fiber-optic temperature sensor according to the change of distance and angle are determined. The measurable temperature range of the fiber-optic temperature sensor is from 25 to $60^{\circ}C$. Based on the results of this study, a noncontact temperature sensor using a silver halide optical fiber can be developed for the temperature measurement of the pH sample in the secondary water system.

• Proceedings of the Korean Geotechical Society Conference
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• 2006.03a
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• pp.1100-1109
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• 2006

In this study, two different technologies which can measure temperature simultaneously at many points are introduced. One is to use a thermal sensor cable that is comprised of addressable thermal sensors connected in parallel within a single cable. The other is to use an optic fiber with Distributed Temperature Sensing (DTS) system. The difference between two technologies can be summarized as follows. A thermal sensor cable has a concept of 'point sensing' that can measure temperature at accurate position of a thermal sensor. So the accuracy and resolution of temperature measurement are up to the ability of the thermal sensor. Whereas optic fiber sensor has a concept of 'distributed sensing' because temperature is measured by ratio of Stokes and anti-Stokes component intensities of Raman backscatter that is generated when laser pulse travels along an optic fiber. It's resolution is determined by measuring distance, measuring time and spatial resolution. The purpose of this study is that application targets of two temperature measurement techniques are checked in technical and economical phases by examining the strength and weakness of them. Considering the functions and characteristics of two techniques, the thermal sensor cable will be suitable to apply to the assessment of groundwater flow, geothermal distribution and grouting efficiency within 300m distance. It is expected that the optic fiber sensor can be widely utilized at various fields (for example: pipe line inspection, tunnel fire detection, power line monitoring etc.) which need an information of temperature distribution over relatively long distance.

• Journal of Mechanical Science and Technology
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• v.16 no.11
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• pp.1550-1557
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• 2002

Diode laser sensor for measuring gas temperature and species concentration in combustion chamber was developed using 2.0 tim distributed feed back lasers. To evaluate the measurement sensitivity of diode laser sensor system, CO2 survey spectra near 2.0 Um were measured and compared with the calculated one. This diode laser absorption sensor was applied to measure gas temperatures in a premixed flat flame of CH$_4$-air mixture. Experimental results were in good agreement with the values by an R-type thermocouple within 6.12%. In addition, successful demonstration of measurement of gas temperature and species concentration in a soot flame showed the promising possibility of diode laser absorption sensors for practical combustion system with non-intrusive method.