Papers by Keyword: Thermistor

Abstract: In this work, the authors tried to solve a typical problem of inexpensive 3D printers using FDM technology: material clogging of the hotend. To cope with the problem, it is necessary to solve the problem of optimization the temperature regimes of the hotend. For this, the temperature fields of the heating device were simulated taking into account the physical properties of the printing materials. Modeling was carried out using the ANSYS software package, the verification of theoretical calculations was carried out in a full-scale experiment. The data obtained was used to upgrade the 3D printer hotend.

Abstract: Temperature sensors are widely used in different industrial and scientific applications. These sensors commercially available in various type and configurations allow the enhancement of automotive systems. The manufactures need to improve and upgrade the technology by research activities regarding the accuracy of temperature measuring using sensors. In this paper will analyze the trends, applications and technologies in automotive temperature sensors. PTC/NTC thermistors are measured and characteristics curves are determined as expression of mathematical functions.

Abstract: The aims of this research is to identify the effect of Nb₂O₅ addition on the electrical properties of Fe₂TiO₅ ceramics-based NTC thermistor.The concentration of Fe₂O₃ and TiO₂ was proportional to Fe₂TiO₅, whereas the concentration value of Nb₂O₅ were 0, 0.5 and 1.0 mole %, respectively. Within two hours, the mixed powder was pressed at 4 ton/cm² to form pellets and sintered at 1300 °C in air. It can perceived from the XRD data that the sintered ceramics had single phase of Fe₂TiO₅, pseudobrookite. From SEM data, it is found that addition of Nb₂O₅ decreases the grain size. The addition of Nb₂O₅ increases thermistor constant, activation energy and electrical resistance of Fe₂TiO₅ ceramics. The values of thermistor constant of Nb₂O₅ added-Fe₂TiO₅ ceramics were relatively large, indicated that the ceramics were aplicable as the NTC thermistor.

Abstract: We propose a tool to calibrate the coefficient variables of the Steinhart–Hart equation, which are used in temperature measurement with a negative temperature coefficient thermistor. The previous method modifies the coefficient variables manually, but the proposed tool takes a measured temperature and automatically modifies the coefficient variable. The proposed calibration tool provides a graphical user interface program for the convenience of users. It is applied to the 4-point temperature measurement of polymerase chain reaction and has a degree of precision of ±0.1 °C in the temperature measurement evaluation

Abstract: The slashing machine is key equipment in textile process, the temperature and moisture regain are crucial technique parameters in slashing or sizing process. The electronic sensor play a key role in intelligence control of technical parameters in term of temperature and moisture regain. The principle, characteristic analysis and application of resistance sensor known as thermistor and humidity sensor have been discussed in this paper.

Abstract: A new measuring method and device were proposed in this paper. It is about the cavity bubble system temperature control factor. It provides reference for research workers in this field. The method is applied in the passive atomic clocks technology, especially the integration filter resonance absorption cavity system temperature control technology.

Abstract: The introduction of the virtual instrument technology provides new ideas for the developments of the temperature acquisition. This paper presents the design of temperature acquisition system based on VI technology. This system takes LABVIEW as the software development platform, simulating environmental temperature parameters via temperature sensors and heaters. Through the USB-6009 data collecting cards environmental temperature is sent to LABVIEW software platform for analysis. The system has the functions of data acquisition, display, storage, callback, save, analysis, printing statements and limit alarm processing and so on, and completes the real-time collection and analysis of the temperature.

Abstract: The microstructure, especially porosity, of PTC (positive temperature coefficient) thermistor based on BaTiO₃ was controlled with a forming pressure. The relationship between theirPTCR properties and microstructureswas investigated with an optical and SEM (Scanning Electron Microscope) images and digital multimeter. Disk samples were fabricated by pressinguniaxially at various pressures of 100~15000kg/cm² and sintering at 1265°C in reducing atmosphere and finally re-oxidizing at 700°C in air. The porosity of the samples decreased rapidly from 45% to 8% with increasing the forming pressure from 100 to 1000kg/cm²andbecame 4% at 15000kg/cm²with slowdecreasing of porosity in the pressure range of 1000~15000kg/cm².With increasing the forming pressure, the resistivity jump of samplesdecreased rapidlyfrom 0.5 to 2.9 at about1000kg/cm²that corresponds tothe porosity of 15% and was saturated above this pressure. It is considered that there is a critical amount of porosity for having PTCR effect, which was about 15% in our samples. In addition, the porosity of the sample has a greater influence on the resistivity jump than on theresistivity at room temperature, which is due to the oxidation of grain boundary through a favorable channel of oxygen such as a pore.

Abstract: A precision temperature control system that uses ATmega128 as the main control microcomputer is built. The temperature is sensed by a Pt100 thermistor, and then converted into the voltage signal by a temperature transmitter to the microcomputer. Two kinds of digital PID (Proportional-Integral-Differential) algorithms are adopted to control the output power of the thermo-electric cooler (TEC) automatically. The test results of the improved temperature control system show that the set-up time of this system is about 340s and the temperature control accuracy is up to±0.1°C.

Abstract: Thermistor has a large temperature range, good stability and resistance to oxidation, which occupies an important position in the low-temperature measurement. This article describes new two-wire thermistor temperature measurement device using the Freescale MC9S12XS128 MCU with sampling capacitance. The device is composed of the MCU with its own A/D, MC9S12XS128 MCU, sampling capacitance, amplifier, boosted circuit, data acquisition and processing system, constant current source, etc. Using constant current source and 16-bit A/D converter designs the temperature measurement circuit, it can eliminate the effect from the conductor resistances in the traditional two-wire resistance temperature measurement system and reduce the measurement error which conductor resistances bring. The method is simple, practical, with high accuracy, strong anti-interference ability and other characteristics.