Physics307L:People/Cordova/Matt's Balmer Series Lab Summary

My partner for this lab was Sebastian
The notebook for this lab can be found here.

SJK 13:57, 22 October 2010 (EDT)
13:57, 22 October 2010 (EDT)
Your summary is a little to thin. I'd like more discussion after the result about sources of error, possibilities for improving, etc. Take a look at Sebastian's summary. Doesn't have to be that long, but his is very good.

Purpose

• Obtain the physical quantity known as the Rydberg constant through the measurement of spectral lines produced by hydrogen gas in an excited state.

Safety

• The tubes are made of glass, and they should be handled with care.
• Glass tubes can get hot after even minimal use. Use caution when handling immediately after use.

Equipment

• Spectrometer - Adam Hilger; London, England; Serial: 12610
• Spectrum Tube Power Supply - Model: SP200 (5000V;10mA; Electro-Technic Products)
• Mercury Tube
• Hydrogen Tube
• Deuterium Tube

Set Up

• Place spectrometer and lamp on a sturdy, flat surface.
• Elevate the lamp to the point where the thinner part of the glass tube (while placed in the lamp) is level with the eye sight of the spectrometer. We used a stack of books.
• Fiddle with spectrometer until you obtain desirable cross hair position and preferred slit width.
• Note: A thinner slit yields more accurate results, but sacrifices visibility.

Results

SJK 13:56, 22 October 2010 (EDT)
13:56, 22 October 2010 (EDT)
See your primary notebook for comment about there being too many digits. It's great that you compare to the accepted value in terms of SEMs. Go one step further and comment on the likelihood of being consistent or whether there's systematic error. 2 SEMs it's unlikely to be consistent, but possible. 11 SEMs means for sure there's large systematic error (compared to your precision).

With our data, the results came out to be

• ${\displaystyle R_{calcHydrogen}=(10976969+/-7304)m^{-1}}$
• ${\displaystyle R_{calcDeuterium}=(10989761+/-1736)m^{-1}}$

The accepted values for these constants are given in the Google doc, and are

• ${\displaystyle R_{hydrogen}=10967758.3406m^{-1}}$
• ${\displaystyle R_{deuterium}=10970746.1986m^{-1}}$

Our result for ${\displaystyle R_{hydrogen}}$ is within 2 SEM. Our result for ${\displaystyle R_{deuterium}}$ is within 11 SEM.