12.02.15 - Calibrating the Thermistor

We started off by building a circuit that uses a thermistor to measure the temperature.

Using the instructions included in our information pack, we used the Arduino and breadboard to set up the circuit. When the circuit was complete, we connected it to the computer with the USB cable. We loaded the ReadAnalogVoltage program into the Arduino.  We were able to see the resistance of the thermistor on the Arduino software. We changed to code to give us a reading every second.



We decided to test the thermistor. We tested it by putting the thermistor in oil at different temperatures. First we put a test tube of oil into a beaker of ice water.We started off at 10 degrees Celsius and went up by 10 degrees Celsius until we reached 70 degrees. We did this by heating the beaker using a Bunsen burner. We put the thermistor in the oil for 30 seconds and recorded the results, we then graphed it.

Temperature  (°C)	Voltage (V)
10	2.25
20	1.86
30	1.62
40	1.28
51	0.92
62	0.63
70	0.47

                                                                                         
                                                                                     

As we increased the temperature of the oil, the voltage decreased. This meant that the resistance of the thermistor increased as the temperature increased. This showed that the circuit and thermistor were working.






We used the software GeoGebra to graph the results.