# Physics307L:People/Young/Young's Oscilloscope

## Contents

# Oscilloscope Lab Summary

^{SJK 01:17, 20 September 2008 (EDT)}

### Purpose

The purpose of this experiment was to explore the functions of the oscilloscope and become familiar with their operation and use in a lab setting through a series of measurements using a wave function generator. Some of the functions used in this lab were Basic Waveform Measurement, AC Coupling, Triggering, and digital storage. In addition to the previous we also found the fall time of our oscilloscope and used our fall time to find the time constant K which is equal to RC.

### What I learned

I have dealt with Oscilloscopes before (both analog and digital) ,but only in very simplistic cases to measure voltage. I found that there was much to be learned about an oscilloscope beyond voltage measurements. As was stated in my notes, the triggering function is an extremely useful method for exploring the parts of a wave with a high time resolution. Closely viewing the waves can be helpful when attempting to acquire accurate readings for voltage or fall time as we found for the end of our lab.

### Results

10% fall time = 2.8±.05ms (.05ms is to account for human error since my eyes can only get cursor so close to the correct position

Starting Voltage= 22±.05V (Again .05 is to account for human error.)

Then to find the fall time constant I used my experimental values in the following equation.

- [math]V(t) = V_0(1-e^{-\frac{t}{\tau}})\quad\iff\quad\frac{V(t)}{V_0}=(1-e^{-\frac{t}{\tau}})[/math]

[Fall Time Equation taken from here]

This is my matlab code solving for K (the time constant.)

V=2.8,Vo=22,t=47e-3 K=-t./log(1-V./Vo)

K=0.3453<-----incorrect read further

#### Correction

^{SJK 00:59, 20 September 2008 (EDT)}

Thanks to Dr. Koch's observations I realized that my equation for fall time was incorrect. The actual equation is K=-t./log(V./Vo) and so with the code corrected my actual value for K is

K =0.0228

### Conclusion

^{SJK 00:56, 20 September 2008 (EDT)}

Overall my understanding of data analysis is minimal and therefore my uncertainty is based solely on the range in which the oscilloscope would fluctuate when giving me readings. The fall time falls within the range of the class average shown on Monday in our class(around 50ms). This leads me to believe that my measurement was close to the true value for my oscilloscope. The K found generally refers to RC. So to take this experiment even further we could find the Capacitance of the system knowing that the systems Resistance.