7. Eliminate edge failures for extended testing by using a couette geometry (cup & bob) Master Curve data collection over long times and many temperatures
13. Forced Convection vs. Radiant Plates Heat transfer is a function of velocity of the air flow moving past the heater and in direct contact with the plate Heat transfer is a function of distance from the heater & thermal conductivity of air Plates Gun Heater Heating Elements Dual Tc Plate & Air Cooling gas input Cooling gas input Tc from Plate
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15. While you can use Forced Air Ovens for asphalt, accurate calibration of air flow and sample temperature are critical to performance. Heat transfer
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18. Dual Heat Exchanger Peltier w/ Preheated Air Purge Peltier Element Tc PT-100 Dual Heat Exchangers w/ Preheated Purge Patent Pending Purge air
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22. Time to Thermal Equilibrium is Key Depending on the heat transfer medium time to equilibrium can be long From the new AI ‘Best Practices Manual’ Start 10 min equilibration time from this point
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24. Asphalt Sample loading time to Thermal Equilibrium Statistics should be used to determine the instruments time to thermal equilibrium
25. Water is the Best Heat Transfer Medium 25 times the thermal conductivity of air Thermal gradients are significant sources of errors. Here you can see a halving of the Modulus just by reducing the thermal gradients
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29. Same Data as previous page (scales are set to be the same as the next page)
30. Addition of an Air Bath to the Chamber (the pre-conditioned purge gas is used to improve thermal conductivity to the edge of the sample)
31. Thermal Hysteresis is very small ( Δ of 1.5% in G* relates to ~ Δ of 0.075 o C or +/- 0.0375 o C)