INFICON 2020ComboPRO Portable Photoionization Detector - Manual (Page 85)

78 ISP-074-575-P1D 78
11.7 eV UV Lamp
General Information
The 2020ComboPRO is equipped with a standard 10.6 eV UV lamp. An 11.7 eV
UV lamp (Part No. MX390024) is available for special applications.
Install this lamp as outlined in Removing and Replacing the UV Lamp on page 84.
When you install a UV lamp other than the standard 10.6 eV lamp, all the response
factors become invalid. You must set the response factor for the current cal memory
to 1. Contact INFICON’s Applications Department for further information.
Limitations of Lithium Fluoride Lamp Window
The 11.7 eV lamp is intended for special applications only. It is not suitable for
normal operation, due to limitations of the lamp window material.
The 11.7 eV lamp window material is lithium fluoride (LiF). LiF is composed of
two light elements which are easily disrupted within the crystal lattice by the UV
light generated by the lamp. Disruption of the lattice causes the crystal to turn a
yellowish color, and performance declines.
NOTE: Due to the lamp window limitations, the useful life of the 11.7 lamp is
limited, and it should be used sparingly.
Unlike other lamp windows, LiF readily absorbs water from atmospheric humidity.
When contaminated by moisture, the window loses its ability to transmit UV light.
NOTE: Do not touch the lamp window or handle it near water.
Using the 11.7 eV UV Lamp
With an 11.7 eV lamp installed, your instrument functions as a detector responding
to compounds which ionize at 11.7 eV or less. The 11.7 eV lamp may be useful for
detecting compounds not ionized by the standard 10.6 eV lamp.
Due to the lamp window limitations, the lifetime of the 11.7 eV lamp is restricted
and it must be used sparingly according to the following instructions.
To use the 11.7 eV lamp in your the 2020ComboPRO:
1. Remove the 11.7 eV lamp from the supplied desiccant bottle and install
the lamp as outlined in Removing and Replacing the UV Lamp on page
84.
NOTE: Do not remove or replace any detector lamp in a hazardous location.
2. Turn on the instrument and wait for the ready status. If the lamp cannot
be started, contact INFICON’s Technical Support Department.