Temperature measurement system

In this lab, we are going to make a device to detect different voltage for different temperature. Goal of this lab is to detect minimum of 0.5 V over a temperature range of 25C to 37C.

We calculated that we need a resistor that is between 4338 ohm to 17800 ohm to have 0.5 V different between 25C and 37C.

We chose 10K ohm resistor as our resistor.

We calculated the voltages we will measure from those temperatures. That is 2.381V and 2.941 V

Setup (1)

Setup (2)

	Expected(Calculated)	Result	Percent difference (%)
Desired fixed resistor	10k ohm	9.84k ohm	1.6
Voltage (hot)	2.941V	2.93V	0.37
Voltage (cold)	2.381V	2.4V	0.798
Voltage difference	0.56V	0.53V	5.36
Thermistor resistance at 25 C0		10.5k ohm
Thermistor resistance at 37 C0		7k ohm

Summary: We have achieved the minimum of 0.5V difference in this design. From varying of many parts we got different number as our calculation, however, percentage of difference was not too much. This kind of design can be used at place you want to monitor temperature and initiate the procedures at desired temperature. For example, when interior of computer system is too hot, it can be shut down, or when temperature of refrigerator is too high, it can start refrigerating.