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Could Galileo's Thermometer Be Adapted to Make a Simple Solar Water Pasteurization Indicator?

I read a webpage that described the Beeswax/Carnauba WAPI, and after seeing the recent reflector activity, I got to thinking about it...

Perhaps a Galileo Thermometer could be employed here with similar results. For those of you unfamiliar with a galilean thermometer, here is a brief and incomplete introduction... It is a glass tube filled with water. Also inside the tube are small sealed spherules of glass containing a measured amount of water and air. As the density of the water (which is dependent upon the temperature) changes, the spherules will sink or float. Please see <> for an example and further explanation.

I believe this may have advantages over the wax variety of WAPI. The "working" element relies on water, not wax. This water will not have issues with chemical breakdown due to UV or heat like the wax might. Water is also ubiquitous, hence much easier to find than beeswax or carnauba. It is easier to use since you needn't turn it over after each use (which ever way its oriented, just wait until the spherule sinks).

Brainstorm time...

Can a pellet of plastic be formulated with sufficient accuracy and precision (and chemical stability) to sink when the water is hot enough, and float when it is not? I'm not an organic chemist, just a displaced astronomer working in the computer field, however I'm almost certain that it could be made to do so. Then, simply add a pellet to a plastic tube filled with water and seal it. When the pellet sinks, the water is at the pasteurization temperature.

Okay, lets go one simpler...Why put a spherule or plastic pellet in a tube just to watch it in the tube? Place the spherule or pellet directly in the water being pasteurized. When it sinks all the way to the bottom, once again you're at the pasteurization temperature. When done, remove the object from the pasteurized water and store both in a clean place. To follow the discussion, click here.

Matthew Collier