Physics307L:People/Ierides/Oscilloscope
Oscilloscope
SJK 22:05, 14 September 2009 (EDT)
In this lab we used an oscilloscope following the Oscilloscope Lab Instructions and obtained significant knowledge as to its usefulness and applications. The main overview and summary of the procedure of the lab is provided by this link:
- The following link leads to the Oscilloscope Lab entry that includes my data, procedure, and observations:
Data Summary
- Fall Time Using "Cursor": 50.4 ± 15 ms SJK 22:00, 14 September 2009 (EDT)
- Fall Time Using "Measure": 83.8 ms
- During our lab we experienced errors in our values using the 'measure' function on our oscilloscope. Because the discrepancy between the two is very large, we decided to use the value that we estimated with the cursor to an error of ± 15 ms to make it more reasonable since + 15 ms meets the measure halfway but still not sure as to whether or not this is correct. We also decided to not include our 'measure' value because of its falsity throughout our lab. Since the 'measure' wasn't functioning properly, I would have replaced the oscilloscope to see if the 'measure' function was working better and I would have repeated the lab and taken more measurements, but my lab partner and I had ran out of time. The time that we had decided to use to find the time constant, [math]\displaystyle{ \tau }[/math], was our 'cursor' value of 50.4 ms:
- [math]\displaystyle{ \tau\equiv -t\div \ln (V_f/ V_i) }[/math]
- [math]\displaystyle{ t=50.4 }[/math]
- [math]\displaystyle{ V_f/V_i=0.1 }[/math]
- [math]\displaystyle{ \tau\equiv-(50.4 ms)\div \ln (0.1) }[/math]
- [math]\displaystyle{ \tau\approx 21.9 ms }[/math]
- [math]\displaystyle{ \tau\equiv -t\div \ln (V_f/ V_i) }[/math]
- During our lab we experienced errors in our values using the 'measure' function on our oscilloscope. Because the discrepancy between the two is very large, we decided to use the value that we estimated with the cursor to an error of ± 15 ms to make it more reasonable since + 15 ms meets the measure halfway but still not sure as to whether or not this is correct. We also decided to not include our 'measure' value because of its falsity throughout our lab. Since the 'measure' wasn't functioning properly, I would have replaced the oscilloscope to see if the 'measure' function was working better and I would have repeated the lab and taken more measurements, but my lab partner and I had ran out of time. The time that we had decided to use to find the time constant, [math]\displaystyle{ \tau }[/math], was our 'cursor' value of 50.4 ms:
Conclusion
What I've learned in this lab was how to use an oscilloscope and how to use some of its features and functions. I've never used one before so this was an exciting opportunity to learn about its uses. In particular I've learned about triggering, the difference between AC and DC coupling, how to interpret an input signal by manipulating it on the screen as well as how to make useful measurements using some of the functions such as 'measure' and 'cursor'. These skills hopefully should improve throughout this semester as we apply them to the following labs.
We didn't get a chance to proceed beyond the AC Coupling section because we were falling behind a bit with time. It wasn't the fact that there wasn't enough time, but because of the inexperience with oscilloscopes we were just a little pressed for time with learning about its functions, etc.
Overall I found this lab to be very educational and I appreciated learning about something that can be very useful in the lab.SJK 22:03, 14 September 2009 (EDT)