If you have a GoGo Board you can use it to keep track of the temperature inside and outside your Pot-in-Pot refrigerator.  We used two temperatures sensors so we could track temperature inside and outside the Pot-in-Pot at the same time.

For more information about how to use a GoGo Board go to the GoGo Board web site.

The GoGo Board does not record actual temperature.  Rather, it reports a value between 0 and 1023 for each sensor reading.  A reading of 0 indicates a closed circuit, such as you would get if you used a switch for a sensor and put the switch in the “on” or closed position. A reading of 1023 indicates an open circuit, such as you would get with a switch in the “off” or open position.  If there is no sensor connected to a given port on the GoGo Board, the reading will be 1023.

Because of the way in which the temperature sensor works – higher temperature results in lower electrical resistance – lower numbers mean higher temperature.  We used two temperature sensors, one in sensor port 1 and the other in port 2.  Before setting up the Pot-in-Pot refrigerator we tested our GoGo Board with the two sensors. Using the Console on the GoGo Monitor, this is what we saw:

The two sensors reported almost exactly the same value.

Then we set up the Pot-in-Pot refrigerator. After it had been set up for a few hours we tested it with sensor1 inside the pot and sensor2 outside.  Here’s what we saw:

Sensor 1 reports a higher value indicating that it is cooler inside the pot.

After a few days the Pot-in-Pot had dried out.  We decided to set it up again and use the GoGo Board to track changes over a long period of time.

We wrote a program to record sensor readings once an hour for 24 hours.

The program records sensor data as soon as it starts, and then once an hour for the next 24 hours.

After 24 hours we uploaded the data from the GoGo Board to our computer in two columns.  We then saved the data as a text file, opened it in Excel and made this chart.

During the 24 hours we collected data it became a bit cooler both inside the pot and outside.  You can see that both sensor readings increased, meaning lower temperature, during that period.  During the entire time it was cooler inside the pot than outside. But, the difference increased in the first few hours.  It takes a while for the Pot-in-Pot to cool down.

More things to try

• It would be interesting to collect data for an even longer period of time.  We predict that as the Pot-in-Pot dries out over time the temperature inside would rise and become close to the outside temperature.
• Once the Pot-in-Pot had dried out, we could add water while still recording data.  We would expect that it would again become cooler inside.
• The idea of the Pot-in-Pot it to keep food cool.  We tried it with an empty pot.  What if we put some vegetables inside?  Would that affect the temperature?