International Conference on Mechanical and Electrical Technology, 3rd, (ICMET-China 2011), Volumes 1–3
374 Designing Transient Hot wire Device by a 40 Micron Shell-Covered Copper Wire
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- Ris (Zotero)
- Reference Manager
This essay examines designing and construction of heat conduction coefficient device for fluids without using Wheatstone Bridge. Already Wheatstone Bridge was used to construct transient hot wire, which needed a complex electronic system and high power consumption. So it had a high cost constructing a Wheatstone Bridge changing with temperature. Moreover, wires with low resistance to temperature ratio like platinum wire with a diameter less than 30 micron are used in these systems, which they cannot be provided in many cases. These designs need three precise temperature sensors. Machining of these devices must be very precise, and if they displace a little, there will be a non-ignorable error.
In a study by Garnier et al (2008), they cancelled temperature sensors and used a 24 micron Tantalum wire. Major fault of this model is a 5% error and using a voltmeter in nano precision. Researchers of the current essay tried to remove this problem. As a result, a new method was developed. In this new method, neither current nor voltage is constant, but relative resistance measurement method and a 40 micron shell-covered copper probe was used that is available easily. The most difference between the results of this design with references was 1.17%.