The goals of this experiment are to measure the wavelengths of the Balmer lines of Hydrogen, and to obtain the wavelength shift between Hydrogen and Deuterium in the H -alpha line.

The experiment begins by calibrating a reflection grating spectroscope for use in later measurements. This is accomplished by taking angular measurements of known wavelengths of Mercury (435.8, 546.1, 577.0 nm) with the spectroscope. Spectroscope readings and Mercury wavelength values are then used to determine the reflection grating spacing.

Reflection grating spectroscope.