*12 - Temperature Measurement Design

INTRO: Today we mainly dealt with a lab that incorporated familiar and unfamiliar components. We again use the thermistor, a device previously described, to create a relationship between temperature and circuit element values.


Pictured below is a thermistor. Since previously mentioned, the following description will be brief. This circuit element changes the current, and accompanying voltage, flowing through it based off of the temperature of the thermistor. For example, to change the current, holding the thermistor, would change the current through it since you are heating it up.


LAB: TEMPERATURE MEASUREMENT SYSTEM
In this lab we will design a DC circuit that will ultimately allow us the ability to determine the temperature. We will use a thermistor, a difference amplifier, as well as a Wheatstone Bridge Circuit.

Pictured below is the basic setup of our circuit. We will go from the thermistor to the Wheatstone Bridge to the Difference Amplifier


 Below is a diagram of our wheatstone bridge circuit. This circuit design is useful since wheatstone bridge circuits are often used to convert variations in resistance to voltage variations.


Here are our measured values for our setup


 Below is a picture of our circuit. As you can see on the right side of our circuit, we have placed a potentiometer. A Pot makes this circuit much easier to since it can be set to the correct resistance to meet our needs.


The next part of the circuit is to go through the OP AMP. We used a difference amplifier to measure the difference between the input and output voltage. Pictured below is the difference amplifier we built