Objective
To determine the Stefan Boltzman constant for radiation heat transfer.
Diameter of test disc(d) = 20mm
Thickness of disc = 15mm
Mass of test disc(m) = 0.5g
Emissivity of Hemisphere = 0.072
Specific heat of copper = 380kJ/kgk
Emissivity of copper disc = 0.072
Inner Diameter of Hemisphere Surface = 200mm
Temp1(°C)
10
Temp2(°C)
10
Temp3(°C)
10
Temp4(°C)
10
T avg(°C)
10
Temperature Gradient
Move the cursor to the graph to see the points
| Time | Temperature |
|---|---|
| 5 | 34.9 |
| 10 | 35.2 |
| 15 | 35.7 |
| 20 | 35.9 |
| 25 | 36 |
| 30 | 36.8 |
| 35 | 38.1 |
| 40 | 38.8 |
| 45 | 39.3 |
| 50 | 39.7 |
| 55 | 40.2 |
Calculation
$$\frac{d_T}{d_t}= 0.11K/s$$
$$Q=m.C_p.(\frac{d_T}{d_t})$$
$$Q =$$
$$W$$
Calculation
$$σ = |{\frac{m.C_p.(\frac{d_T}{d_t})}{A(T_{avg}^4 - T_d^4)}}|$$
$$Td = Disc \space Temperature = 40.2°C$$
$$σ = $$
$$\times 10^{-8}W/m^2k^4$$
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