Education and Manpower Bureau
Using Datalogger in the Teaching of Physics


Light Bulbs Testing

Experiment Profile:

1. Background
There are many different models and brands of light bulbs on the market which claim to use less electricity but provide more brightness than traditional light bulbs. Next, we will carry out tests to see which light bulbs are the best.

2. Objective
To test the light intensity for different brands of light. bulbs
To test the energy used for different brands of light. bulbs

3. Equipment List
Datalogger interface connected to a PC
Light sensor
Light bulbs of different brands and models
Power supply




1. Connect the datalogger interface to a PC with the software installed.

2. Connect the light sensor to the datalogger interface and fix the light sensors on top of the light bulb with the stand.

3. Start recording the data of light intensity for around 20 seconds with the light bulb turned off..

4. Turn on the light bulb and keep the datalogger onto record the light intensity for 5 minutes.

5. Stop recording the data and save the data file for this light bulb.

6. Repeat steps 2 to 5 with another light bulb.


1. Plot a graph of light intensity against time for each of the light bulbs.

2. Is there any difference in the graphs you get from different light bulbs? Try to explain for the difference.

3. Suggest which light bulb model you find the best and give your reasons to your classmates.


Calculate how much energy is saved from the light bulb compared with traditional light bulbs.

Role play: You are a light bulb salesperson. How would you sell your product to your classmate?

Video Download:

We are particularly grateful to King Ling College provide this video.

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