Absorption Cell

The 30W lamp will become hot during operation. Allow adequate cooling time before handling and warn students not to touch the lamp or its housing during or immediately after the demonstration.

Mercury thermometers contain toxic mercury. Handle carefully to avoid breakage. Have a mercury spill kit available and know proper cleanup procedures. Consider using alcohol or digital thermometers as safer alternatives.

Ensure the 6V transformer is properly grounded and connections are secure. Keep water and liquids away from electrical components.

Purpose

Demonstrates that light carries energy by showing a thermometer inside an absorption cell reaches a higher equilibrium temperature than an external reference thermometer when illuminated. Provides direct evidence that electromagnetic radiation is a mode of energy transfer.

Absorption cell — a dark cylindrical cell on a stand with two mercury thermometers, one inserted through the cell and one mounted externally

Figure 1:

Warning: Hot Lamp Surface

Warning: Mercury Thermometer Handling

Warning: Electrical Safety

Purpose

Safety Warnings

Warning: Hot Lamp Surface

Warning: Mercury Thermometer Handling

Warning: Electrical Safety

Purpose