Physics307L:People/Wilkinson/Oscilloscope
Oscilliscope Lab Summary
SJK 14:27, 24 September 2010 (EDT)
This is a good lab summary. Good length, easy to read. I liked that you and Tyler explored the AC coupling a bit further and looked at the 6.7 V transformer too. The main thing missing from the summary is quantitative estimate of uncertainty for the fall time, and comparison to accepted value. This comparison is tough to do for o-scope, but will be essential for Millikan and future labs.
Goal of the Lab
The goal of this lab was to get acquainted with the oscilliscope. We were also introduced to basic lab technique, data collecting procedure, and safety practice.
Learned
I learned that the oscilliscope can be a very useful tool in a lab setting. It is a machine that displays a plot of voltage vs. time. The oscilloscope I used (Tektronix TDS 1002) had several important functions/features.
- Measurment Features
This scope was able to measure the frequency, amplitude, and period of a repeating signal. This could be done by using the cursors (push the cursor button near the top of the machine and select which axis (time or voltage) to measure). This could also be done by using the measure feature (push the measure button and select (peak-peak) for the amplitude, there were several other useful measurment features including one that records the fall time of the scope).
- Display
The display options on the scope were also very useful. Using the VOLTS/DIV knobs one is able to 'zoom' in and out on the signal. A third knob modulates the number of displayed periods/cycles.
- Triggering
The triggering function of the scope has wide utility. It's name implies its function. This fucntion allows the user to prescribe if and when the osscilliscope begins recording data. In the case of a repeating wave (sine for example) the machine can be set to trigger on a certain amplitude (by hitting the triggering butting then turning the triggering knob). It can also shift the phase of the displayed wave by being able to trigger on a rising slope or a falling slope. I can see the triggering function being helpful when looking for a certain voltage spike above some noise.
Data
Using several of the display features and the measure function I was able to record a fall time of 34.7 ms. Lab Data
Other data included some interesting observations of a AC/DC transformer. We found a repeating pattern in the signal structure that was clearly not DC voltage. We hypothesized that this signal was a relic of process used to transform AC to DC.
