User:Garrett E. McMath/Notebook/Junior Lab/2008/09/08

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 * style="background-color: #EEE"|[[Image:owwnotebook_icon.png|128px]] Oscilloscope Lab
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Oscilloscope Lab 1

 * To learn how to use an oscilloscope and write a lab report for physics 307L.

Lab Notes
Caution: A terminator should be used when doing this lab given the resistance of 50 Ω a danger of reflected RF signal is possible according to Wiki webpage http://en.wikipedia.org/wiki/Electrical_termination.

Measurement DC vs. AC Fall time RC Value
 * I measured a peak to peak voltage of my sine wave to be 3.88V, and a frequency of 203.3mHz using the cursors.
 * Using the measure feature on the ocsilloscope i got values of 3.88V, and 202.8 +/- .4 (due to fluxuations during measurement)
 * Using different waves from the generator the oscilloscope measured very similar values for all.
 * Obviously I believe that measuring by grid lines is the least accurate way to take these measurements, the next being the cursor menu, and finally the most accurate being the measure feature on the oscilloscope.
 * The first noticible difference between AC and DC coupling was the amount and speed of fluxuation in the ongoing measurement of both peak to peak Voltage and frequency.
 * Probably the biggest problem with AC vs DC was with the square wave. DC coupling allowed for near perfect box representation of the wave while AC was asymtotic on both top and bottom of the wave function.  I believe this has to do with the AC couplings high pass filter but I don't know specifically why.
 * When I measured the fall time of of the AC coupling I noticed a huge difference depending on the graph choice.
 * I measured the fall time using AC coupling with zero DC offset and an amplitude of 8.6V. The value I got using the cursors was 51 milliseconds, and with the measure feature I got a value of 52.2 milliseconds, though it did fluxuate by approximately +/- 2 milliseconds.
 * Using the formulas on wikipedia for RC value, I found a calculated fall time of 48 milliseconds which is very close to my expirimental value of 52.2 which was calculated by the oscilloscope.



Lab Summary

 * The oscilloscope lab
 * This lab was very informative as I had never used an oscilloscope before. The menus and tools on the oscilloscope were surprisingly intuitive and easy to use.  As the closest instrument I have used to the oscilloscope is a simple multimeter; the oscilloscope was incredibly more informative with how the readings one gets from a multimeter are attained.  Also with all the features on the oscilloscope one can measure the readings three different ways in most cases.
 * The main measurement in this lab was the AC coupling fall time. I measured the fall time using AC coupling with zero DC offset and an amplitude of 8.6V. The value I got using the cursors was 51 milliseconds, and with the measure feature I got a value of 52.2 milliseconds, though it did fluxuate by approximately +/- 2 milliseconds.  Later using the formulas on the wiki page for RC values and rise time (See Wikipedia article on rise time) I got a calculated a fall time of  48 milliseconds which was reasonably close to my experimental value of 52.2 milliseconds.


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