infrared

• aim - investigate how much infrared radiation is absorbed or raditated by different surfaces
• 1 - use a Leslie's cube to see how much infrared is emitted from different surfaces. this cube has 4 different surfaces, a shiny metallic one, a white surface, a shiny black one and a matt black surface
• 2- fill the Leslie's cube with hot water then point an infrared detector at each of the four surfaces and record the amount of infrared emitted . make sure to keep the same distance between the Leslie's cube and the infrared detector to make the measurements repeatable
• 3- you should find that matt black emits the most infrared radiation. the shiny metallic surface emits the least.
• 4- if we do not have an infrared detector, use a thermometer with the bulb painted black, however resolution is less
• 5 - to measure absorbance of infrared by different surfaces using an infrared heater and on either side two metal plates. one painted shiny metallic plate and the other matt black. attach a drawn pin. switch the heater on and start a timer
• 6- the temperature of the metal plates increases as they absorb infrared. record the time it takes for the Vaseline to melt and drawing pins to fall off
• 7 - the drawing pin falls of the matt black plate first because it absorbs more infrared