Atmospheric Processes - Radiation

1
Atmospheric Processes - Radiation

• Raheel Aslam
• Prasad Weerakoon

2
Testing Procedures, Problems and objectives
300W Bulb Lamp

• Which material absorbs more heat in the first ten
  minutes ?
• Procedures
• We filled the pans to the same level with
  different materials.
• Placed those pans under the lamp about 12
  inches.
• Placed thermocouples just under the surfaces of
  each material.
• Turned the lamp on and measured the temperatures
  for ten minutes.
• Using the data tables, we plotted the graph of
  the heating cycle to compare the rates.
• Even though there was not enough intensity of
  light, we still got pretty good results as
  expected.

Dark Wet Soil
Light Sand
Water
Stop Watch
Thermocouple
3
Data tabels and Graphs
Surfaces Heating Cycle Heating Cycle Heating Cycle Heating Cycle Heating Cycle Heating Cycle Heating Cycle Heating Cycle Heating Cycle Heating Cycle Heating Cycle
Surfaces 0.0 1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0 9.0 10.0
Water (C) 21.0 21.3 21.6 22.0 22.5 23.0 23.5 23.9 24.2 24.5 25.0
Dark wet soil (C) 12.7 14.2 15.6 16.8 17.9 19.0 20.1 21.3 22.4 23.6 25.2
Light sand (C) 14.1 14.9 16.0 17.2 18.4 19.6 20.6 21.6 22.4 23.4 24.1
4
Discussion and Results

• From the graph, it was clear that dark-colored
  objects absorb more visible radiation.
• It was wet dark soil with some grass and plant
  roots, which might have caused results to
  deviate.
• Basically, results showed gradual increase in the
  temperature of three material surfaces.

• To get better results, use a reflector lamp
  which provides
• high intensity of light.

5
Conclusions and Recommendations
From the results we can conclude that the amount
of energy absorbed by an object depends on the
following 1. The object's absorptivity, which,
in the visible range of wavelengths, is a
function of its color. 2. The intensity of the
radiation striking the object
As mentioned in the previous slide, the soil that
was used had impurities in it and that may have
changed our reading somewhat. However, that can
be ignored as the percentage of impurities is not
significant enough to change the abosrptivity of
the soil sample.