Happy Birthday to Me

I recently had my birthday.  My parents sent me some money and I used it to buy something I've wanted for a long time.  I've wanted a thermometer that can be plugged into my computer for a long time.  I have also been gaining an interest in electronics.  I have a simple analog voltmeter but it doesn't do anything else.  So I purchased a multimeter that also has a thermocouple that can plug into my computer via an infrared link.  The infrared link protects my computer from the electronics in the multimeter or the things I attach it to.  I put the thermocouple into a test tube full of water and dropped it into the deep freezer.  I had it sample the temperature every two seconds and recorded the graph below.

Some of the cool things to notice are the supercooling of the water before freezing.  The water cooled to -1.1 degrees before it started to freeze (~1000s) at which point it warmed up to 0.6 degrees as the water released energy as it starts to crystallize (the heat of crystallization for water is ~6 kJ/mol) .   It then cooled to 0 and stayed there for the next 25 minutes until all of the water had frozen and then it began to cool the ice.

Thanks for the great toy Mom and Dad!