Temperature Measurement and Control of Fiber Drawing Furnace Based on Virtual Instrument

2012 ◽  
Vol 529 ◽  
pp. 507-511
Author(s):  
Lei Chen ◽  
Zhong Dong Wang

The temperature in fiber drawing is one of the key factors influencing fiber’s performance. To the temperature measurement and control problem, the four-wire lead configuration of Pt100 with current excitation was adopted, the signal conditioning circuit includes constant current source, instrumentation amplifier and anti-aliasing filter. The computer collected signals from the conditioning circuit and output control signals by data acquisition card PCI-6221M. The software program was based on LabVIEW, the function relationship between resistance and temperature based on international thermometric scale and the digital filter were applied to calculate temperature. The improved PID control algorithm and the PWM technique were used to realize the temperature control. The experiment results show that the deviation is 0.71°C when the average temperature of the furnace center is 170.25 °C, which satisfies the design requirements.

Author(s):  
Peter Rodgers ◽  
Arman Molki

Hands-on laboratory skills play a vital role in providing students with a sound understanding of the scientific fundamentals and their application in solving real-life engineering problems. One of the essential laboratory based courses taught at our Institute is Introduction to Measurements and Instrumentation. The design and implementation of such a course has been well documented in Western engineering education, but presents specific challenges in the Gulf region due to economical, social and cultural factors. This paper discusses the adaptation of corresponding Western courses to undergraduate mechanical engineering studies in the Gulf region. Laboratory exercises for temperature measurement and control are described, which consist of four modules, each building upon the other. In each module, students learn how to design an accurate measuring system, and process and interpret collected data. In the first module, the students are required to build a thermocouple reader using an AD620 instrumentation amplifier and to compare measurements with NIST reference tables. The second module is an introduction to LabVIEW, a graphical data acquisition programming language. The students are required to write a LabVIEW program to record multiple thermocouple signals from a heated plate under varying convective cooling conditions, using a high resolution temperature logger with on-board signal conditioning. The third and fourth modules focus on temperature control techniques. In the third laboratory exercise, the students are required to construct an electrical circuit using a low-power PCB relay and NPN bipolar transistor to develop a bang-bang linear temperature controller. The program created in module two is modified to have the heater operation automatically controlled for a fixed temperature set point. In module four, the students replace the bang-bang controller built in the previous lab with a commercially available PID controller and explore the differences between PID and linear temperature control systems. For each module, students are required to submit a formal report covering the theoretical background, the experimental procedure employed, uncertainty analysis, and conclusions and recommendations. An effective teaching strategy is outlined that covers the fundamental concepts of temperature measurement and control through carefully designed experiments, with sample results presented. Emphasis is placed on the tailoring of the course topics to engineering education in the Gulf region.


2013 ◽  
Vol 718-720 ◽  
pp. 450-454
Author(s):  
Ning Yang ◽  
Hai Ting Zhu ◽  
Shao Shan Zhong

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.


2013 ◽  
Vol 385-386 ◽  
pp. 492-495
Author(s):  
Dong Bing Dai ◽  
Ya Jun Wang ◽  
Ye Ping Sun ◽  
Zheng Guang Liu

Virtual instrument is a result of the computer combined with some instrument hardware, working for the instrumentation applications, it is one trend of the instrumentation development .This paper presents a design of a high-power and high-precision constant current source, studied three different electrical testing technologies based on constant current source and propose the principle of integrated the three electrical test technologies on a virtual instrument platform. A multi-function virtual instrument system based on LabView language, USB data acquisition card and a constant current source has been developed. This system has a high accuracy, high integration and a thecapability of further development etc..


2014 ◽  
Vol 511-512 ◽  
pp. 294-300
Author(s):  
Tian Tian ◽  
Zhen Yu Li ◽  
Tian Gao ◽  
Fang Yao Liu ◽  
Jian Wu

Base on the virtual instrument technology, a micro signal measurement system was established and applied to the electronic teaching experiment. It is composed of PC, oscilloscope, signal generator, ac constant current source, low noise preamplifier and tested operational amplifier, etc. it can complete the measurement of uV weak voltage, uA weak current measure, wires and printing plate conductor resistance and inductance, amplifier open-loop amplitude frequency and phase frequency characteristics, and so on many aspects of modern electronic measurement experiment content. The system not only has the characteristics of functional diversity, measurement accuracy, and good graphic interface, simple operation and overcomes the shortcomings in the course of electronic technology experiment teaching, and play an important role on improving the experimental conditions,reducing the cost of experiments, raising the level of classroom teaching and practice of teaching.


2011 ◽  
Vol 20 (02) ◽  
pp. 267-286
Author(s):  
STEVE WINDER

This paper outlines the various driving and control techniques for Light Emitting Diodes (LEDs). LEDs should be driven from a constant current source. High power LEDs are usually driven from a switching regulator, for reasons of efficiency. The types of drivers described include Buck (step-down), Boost (step-up) and Buck-Boost (step-up or step-down). Isolated drivers and Power Factor Correction (PFC) circuits are also described. This brief paper can only describe the basic outline of these circuits, but this should be sufficient to allow the basic principles to be understood.


2013 ◽  
Vol 423-426 ◽  
pp. 2559-2562 ◽  
Author(s):  
Long Liu ◽  
Yun Cui Zhang ◽  
Shen Hua ◽  
Jun Xiao ◽  
Li Jia Huang

This article describes the design of High-Precision Temperature Measurement System based on C8051F350 and PT100. The system consists of the control circuit, temperature sensors, signal amplification circuit, field bus interface circuit. The system adopts constant current source method and a differential measurement circuit. A 24-bit A/D built in the CPU is used to sample the data and Non-linear compensation by software algorithms for it. The design improves the accuracy of the temperature measurement system.


2011 ◽  
Vol 301-303 ◽  
pp. 1333-1338
Author(s):  
Qing Fu Du

Calibration of general temperature sensor, platinum resistor is done with measuring its zero resistance and dispersity of linear system and compensating. Accurate constant current source is used to provide platinum resistor sensor power and four-wire measuring method is designed for self-compensation of lead wire resistance. With amplifying the changing signal of platinum using amplifier of high precision and low temperature drift, and MCPU digital filtering, highly accurate temperature measurement result is got finally.


2013 ◽  
Vol 347-350 ◽  
pp. 111-116
Author(s):  
Tian Tian ◽  
Xu Min Zhao ◽  
Li Na Zeng ◽  
Yu Tao

According to the critical issue of accurate measurement of small resistance in the field of electronic measurement, the micro-ohm resistance measurement system is designed based on LabVIEW. It consists of two parts: hardware and software. The hardware is composed of AC constant current source, reference signal source, low noise amplifier, data acquisition card, computer etc.; The software consists of man-machine interface program, measure and control program and data processing program. The system based on virtual instrument cross-correlation detection technology achieves the effective measurement of micro-ohm resistance. It is an automatic measuring system with a flexible and convenient programming, simple and accurate measurement, high resolution and stable performance.


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