User:David K. O'Hara/Notebook/physics 307 lab/Oscilloscope lab notes

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Oscilloscope Lab

SJK 16:48, 15 September 2009 (EDT)
16:48, 15 September 2009 (EDT)
In general, you need more detail in your primary lab notebook. One way of illustrating this is that your lab summary has more information that your primary lab notebook. What this means is that you were relying more on your memory than what you had written down. Of course, you're going to do that, but you want to make sure that you write down as much as possible (including thoughts and musings) while you're in the lab, because there will often be instances where you can't remember what you did. Furthermore, the primary lab notebook is supposed to make it possible for someone other than you to figure out what you were doing. So, in your future labs, make sure to take more notes during lab time!

Overall, you did a good job with the hands-on and the lab summary--mostly just the primary lab notebook needs improvement.

Purpose of this lab is to become familiar with oscilloscope operation and wiki editing.


Be cautious when moving energized electrical equipment. No open drinks or other unsafe behavior is acceptable while working with energized electrical equipment.
To protect the equipment that will be used, do not exceed voltage or amperage ratings.

Equipment Used
SJK 16:43, 15 September 2009 (EDT)
16:43, 15 September 2009 (EDT)
Good job recording exact model numbers of equipment used. A picture of the setup would be very helpful! In future labs, see if you can add photos (ask me or other students for help if you need to).

Tektronix tds1002 two channel oscilloscope
BK Precision 10MHz sweep/function generator

Lab Procedure
SJK 16:45, 15 September 2009 (EDT)
16:45, 15 September 2009 (EDT)
Definitely a link to the oscilloscope lab procedure page would be appropriate here. Something like "I am following the procedure outlined on the o-scope lab page."

Becoming familiar with oscope controls.

Triggering: allows a stable representation of the waveform to be displayed on the scope.

Effects of using different triggers:
video - shows continuously moving waveform, difficult to read
pulse - had no effect, display was similiar to video
edge - stable representation of waveform, generates a pulse when signal crosses a given threshold voltage

Measuring values off oscilloscope

using a 200hz sine wave signal from a function generator measure the peak-peak voltage (amplitude) and the period (giving frequency)

perform measurements using oscope display divisions, cursors, and finally measure function.
measurement type voltage period frequency
display 2.3 v 4.8 ms 205 hz
cursor 2.24 v 4.84 ms 206.4 hz
measure 2.24 v 4.840 ms 206.446 hz

compare AC coupling to DC coupling

AC coupling shows entire wave makeup, both AC and DC parts.

DC coupling shows waveform with only DC component. Filtered waveform.

measuring fall time.

set the function generator to output a square wave with 0 dc offset, and an amplitude of 8.6 volts @1.1hz measured the fall time from the peak of the signal to 10% of the signal to be 53.3 ms.

The time constant τ of the system is given by fall time = 2.197*τ

in this case τ is approximately .024.