Assembly Drawing: Assembly Drawing Version 1.0
Heating Element Options:
1.a: Heavy Duty Soldering Iron + Adjustable Power Supply
-A 500W adjustable power supply will provide constant power to a heavy duty soldering iron capable of sustaining 500W. This soldering iron will be interfaced with the test sample to provide heatflux through the sample. The heavy duty soldering irons currently on the market are expensive (~$300.00) therefore it might be prudent to check whether a lower power soldering iron will suffice. This will likely result in a smaller size sample in order to accomodate a lower power soldering iron.
However, after some initial calculations, q=-kDeltaT, for most metals a standard COTS soldering iron, for example, should be more than enough to meet the temperature requirements set forth. A 50 Watt power supply/regulator will keep the power going to the iron constant. Therefore our q value will be constant, the Delta T will be measured, and K can then be calculated by the students. I don't think there is a critical need for heat flux sensors.
One of the next steps will be to start looking into samples and sample sizes. It would be good to decide on a list of materials (Eg. steel, bronze, aluminum, copper) so that we can begin calculating what size sample we can use based on the power supply.
Here is a link that basically describes the lab we are working for: http://www.the-three.net/documents/portfolio/thermal_conductivity_report.pdf
Thermal Paint Links: 1. http://thermalpaint.com/main.html
ASTM Standards for Thermal Conductivity Testing: http://enterprise.astm.org/filtrexx40.cgi?+REDLINE_PAGES/E1225.htm
Critical Radius of Insulation: http://en.wikipedia.org/wiki/Heat_transfer#Critical_insulation_thickness