Investigating heat loss due to radiation: DrDAQ as a temperature probe

Introduction

DrDAQ is being used here as a dual temperature probe. In both KS3 and KS4 science students have to be aware of the heat loss from objects due to radiation. Radiation is an electromagnetic wave which can travel through a vacuum. You cannot see it with the human eye but firefighters use special cameras which can see this type of radiation. All hot objects will lose energy in this way. In hot countries the people wear light coloured clothes and if you wear black on a hot day you seem to feel hotter. This experiment is examining whether colour can effect how heat is lost

Equipment required

• DrDAQ data logger connected to a PC
• Two external temperature probes (DD100)
• One 250 ml conical flask painted black and one with silver foil around it
• A kettle or other resource to boil water
• Two pieces of insulating material to place over the top of the flasks be (these will have to be made with a small hole to let the temperature probe into the flask)
• Two clamp stands

Experiment setup

• Fill both the conical flasks with boiling water
• Place the insulating covers over the top of the flask
• Place the temperature probes in the flasks
• Start recording the temperatures of the flasks (15 minutes should be long enough)

Figure 1: diagram showing the experiment set up

Carrying out the experiment

Safety is paramount here. Take great care when transferring and handling boiling water. I suggest clamping the flasks down to avoid the risk of spillage.

Questions and discussion of results

1. Which flask dropped in temperature the quickest? Quote results to prove your point
2. Can you suggest a link between the colour of the flask and how quickly the heat was lost?
3. Use textbooks and/or the internet to find some scientific reasons why one coloured flask cooled more quickly than another.

Further study

• Can you design an experiment to discover if different coloured flasks full of water would heat up more quickly than others? Show your teachers your design
• Why was an insulating cover placed over the top of the flask?