3/9 Temperature Measurement System

        The purpose of this lab is to observe the resistance change when the temperature changes.

1. Provide:
      a:

based on the calculation we did on the white board, the resistance should between 4367 and 17633. Therefor, we choose the medium value 10K.

     b.: according to those formula, when R = 10K the change of voltage should be 0.6337V.

     c: We except that when we increase the temperature, the voltage should also increase.

2. Rth at room temperature R = 9.9k

    Rth at 37, R = 5.9k

3. The actual value of R is 9.8K

4.Measurement: 

5.

     a. when we increase the temperature from room temperature to 37, the voltage increase from                     2.46V to 3.09V. Therefore, the output voltage increase as temperature increase.

     b. the change of voltage is 3.09V - 2.46V = 0.63V.

         the change of temperature is 37 - 25 = 12

         0.63/12 = 0.0525

         In this case, our design meet the design requirements.

Summary

       In today's class, we learned the basic concept of resistance. We learned that the resistance of thermistors will change if the temperature changes. Then, we did a experiment with the thermistors