Heat absorbing tube, bright polished

To prove the absorption of heat radiation depending on the surface finish;
after only 5 minutes a clear difference in temperature is visible!
Aluminium tube with flat bottom and rim, bright polished
dimensions: D= 15 mm, L= 100 mm
weight: 3 g

additionally required:
1 x C7320-1D Stopper silicone, 12/18/27 mm, 1 hole
1 x P2220-1A Thermometer with graduated scale, -10 … +110 °C
1 x P2621-1B Mounting bracket for heat absorbing tubes