Model A: A laboratory thermometer is placed inside a large pickle jar which is left uncovered.
Before placing the thermometer, tape it to a strip of cardboard that is a little bit longer and wider
than the thermometer. Stand the thermometer on the bottom of the jar and lean it at a slight
angle against the wall of the jar.
Model B: Like Model A, except that the jar opening is sealed with clear plastic wrap and a rubber
band. Before sealing the jar, spray or wipe a light film of anti-fog solution on the inside of the
pickle jar. This coating will make it possible to read the thermometer in the event that water vapor
condenses on the inside of the jar during the experiment.
Model C: Like Model B, except that a jelly jar filled with water is added to the setup. Start by
spraying or wiping the anti-fog solution onto the inside surface of the pickle jar. Fill the jelly jar
almost to the top with water and place it inside the larger jar. (Important: The water should be
brought exactly to room temperature before use.) Add a laboratory thermometer to read air
temperature inside the pickle jar. Place a second thermometer inside the water-filled jar. The
two thermometers should face the same direction.