The colour of temperature

Incandescence is the emission of light by a solid that has been heated until it glows or radiates light. When an iron bar is heated to a very high temperature, it initially glows red, and then as its temperature rises it glows white. Incandescence is heat made visible – the process of turning heat energy into light energy.

In this activity you will examine the light from a filament. You will observe and measure the colour of the filament at a range of voltages against the brightness.

Equipment:

Metal colour chart

video equipment

tracker equipment

You may need to set the exposure on the ipad, read how to do this here

Colour and heat from an incandescent source are related. Watch this video

We can use this colour chart to determine the temperature of the hot filament in an incandescent light globe..

In this activity you will observe the thermocouple as you move it slowly within the bunsen burner flame. We will try to identify several of the colours above and their corresponding temperatures

Fill in the table below

Analysis

import your video into tracker and and use the line

Discussion

1. Describe the shape of your curve

2. How does this relate to the Stefan–Boltzmann law?

3. Can this data be compared?

Great video on the engineering of incandescent globes