Teledyne T100, Instruction Manual, Page: 225 / 404

Teledyne ML - T100 UV Fluorescence SO2 Analyzer Theory Of Operation
06807A(DCNxxxx) 225
Figure 9-2: UV Light Path
9.1.3. UV SOURCE LAMP
The source of excitation UV light for the T100 is a low pressure zinc-vapor lamp. An
AC voltage heats up and vaporizes zinc contained in the lamp element creating a light-
producing plasma arc. Zinc-vapor lamps are preferred over the more common mercury-
vapor lamps for this application because they produce very strong emission levels at the
wavelength required to convert SO
2
to SO
2
*, 213.9 nm (refer to Figure 9-4).
The lamp used in the T100 is constructed with a vacuum jacket surrounding a double-
bore lamp element (refer to Figure 9-3). The vacuum jacket isolates the plasma arc from
most external temperature fluctuations. The jacket also contains thermal energy created
by the lamp’s operation therefore helping the lamp to heat up and maintain proper
vaporization temperature. Light is emitted through a 20 mm x 5 mm portal.