Spectrum Tubes Deuterium, glass tubes approximately 10-1/4in (260mm) long, central capillary portion approximately 3-1/2in to 4in (90-100mm) long with electrodes sealed at both ends and connected to lead wires protected by metal caps.
Spectrum Discharge Tube, Mercury Gas to show spectral lines of pure substances. Tubes approximately 260mm long, central capillary portion approximately 3-1/2 to 4 (90-100mm) long with electrodes sealed at both ends and connected to lead wires protected by metal caps