Physics307L:People/Frye/BalmerSeries

Steve Koch 04:59, 21 December 2010 (EST):Very nice data and spreadsheet. But again missing is a statistical comparison with the accepted values. And any discussion of whether H and D spectra can be distinguished with your instrument and technique.

Balmer Series
This lab was performed in the junior laboratory in the UNM physics building on October 25th and November 1st with Alex Benedict. Following the procedure outlined in Dr. Gold's lab manual

Links
[Dr. Gold's Lab Manual]

My Lab Note book

Alex Benedict's Note book

Procedure
Procedure:

The goal of this lab is to calculate the Rydberg using the Rydberg Formula :

$$\frac{1}{\lambda }=R(\frac{1}{n_{1}^{2}}-\frac{1}{n_{2}^{2}})$$

We do this by first measuring the wavelengths in the Balmer series ($$n_{1}=2$$) and then calculate R.

We calibrated the spectrometer using two methods. one the first day we followed the procedure from the lab manual and physically made the instrument agree with known values from the Hg spectrum. On the second day we used a linear fit to adjust our measured values to known values of the Hg spectrum and then used the same fit on our measured values of Hydrogen and deuterium.

here are our measurements and calculations

Results
The uncertainty here comes from the standard error of the mean and so all of these values are reported with a 68% confidence interval:

Calculated R using measured hydrogen wavelengths (physical calibration): R=1.0982(24)E+007 1/m

Calculated R using measured deuterium wavelengths (physical calibration): R=1.09885(76)E+007 1/m

Calculated R using measured hydrogen wavelengths (mathematical calibration): R=1.0996(25)E+007 1/m

Calculated R using measured deuterium wavelengths (mathematical calibration): R=1.0981(41)E+007 1/m