Temperature Measurement System

Temperature Measurement System

In the lab, we design a temperature measurement system with a termistor, a resistor, Vout Voltage, and the 5V power supply. Before doing the lab, we determine Vout as a function of Rth and R. 

From this Picture, Vout is calculated. Then we verify if the Vout temperature increases as temperature increases and by using the quadratic formula in the picture above, it is confirmed that it does. 

When the circuit was set up. We check to see the resistance at room temperature and watch what happens as temperature increases:

From the picture it is shown that as temperature increases (As I touch the Thermistor) the resistance Rth decreases. 

Now we record the voltage of the circuit from when it is at room temperature and from when I touch the thermistor. 

From the picture shown, Voltage increases as temperature increases. when I was taking the picture as I'm touching the thermistor, the Voltage kept increasing. 

From the calculated Voltage: 

10.95kΩ would be calculated to 2.39 V

6.39 kΩ woudl be calculated as 3.05V. 

Doing the % error: 

1.3% error for the 10.95kΩ

and

2.3% error for the 6.39kΩ

At the lecture, we learn about the nodal analysis and how the method was used.

On this problem, we need to calculate the node voltage on the circuit: 

Using KCL and Ohm's law, we get that: 

V1 = 13.33V

and

V2 = 20V

Summary

In the lab, we record the voltage of the thermistor.  After recording the voltage which is at room temperature, we touch the thermistor to record the voltage. When we touch the thermistor, it increases temperature which also increases the voltage. This is because as temperature increases, the resistance decreases.