User's Manual

012-04695D Thermal Radiation System

Calculations

① For each value of X, calculate 1/X

. Enter your results in Table 2.2.

② Subtract the Average Ambient Radiation Level from each of your Rad measurements in

Table 2.2. Enter your results in the table.

③ On a separate sheet of paper, make a graph of Radiation Level versus Distance from Source,

using columns one and four from Table 2.2. Let the radiation level be the dependent (y) axis.

④ If your graph from part 3 is not linear, make a graph of Radiation Level versus 1/X

, using

columns three and four from table 2.2.

Questions

① Which of the two graphs is more linear? Is it linear over the entire range of measurements?

② The inverse square law states that the radiant energy per unit area emitted by a point source

of radiation decreases as the square of the distance from the source to the point of detection.

Does your data support this assertion?

③ Is the Stefan-Boltzmann Lamp truly a point source of radiation? If not, how might this

affect your results? Do you see such an effect in the data you have taken?