Copyright Resonance Ltd., December 2011
143 Ferndale Drive North, Barrie, ON L4N 9V9 Tel: 705-733-3633 Fax: 705-733-1388 Email:sales@resonance.on.ca
Resonance PID mm & mm PID Bulbs
Photo-ionization lamps are compact, rugged, low-pressure gas discharge lamps used in photo-ionization detectors (PIDs)
to measure various volatile organic compounds (VOCs).
Resonance mass produces an extensive range of RF excited lamps filled with a variety of gases. In these lamps, the
natural "RESONANCE" frequency of the gas is excited by plasma in the bulb. Combinations of the appropriate fill gases
and window materials are used to select near monochromatic energies in the 11.7 to 4.9 eV range. Unique sealing and
processing technologies developed during work for the US and Japanese space programs yield lamps of exceptionally
high stability and output. Burn-in and VUV testing of every lamp ensures the best quality to meet customers' requirements
throughout the world.
Operation
In a low-pressure RF-excited gas discharge lamp electrons collisionally excite atoms in the lamp causing them to emit at
highly specific spectral emission wavelengths. These spectral "lines" will typically appear in all spectral regions down to
the short wavelength cut-off of the window. In Resonance's lamps the presence of unwanted "impurity lines" is minimized
and is typically far less than 0.1 percent. This insures that the species-to-species photoionization sensitivity of a PID
equipped with a Resonance lamp will not change from lamp to lamp or drift with time.
The most commonly used lamp for PID purposes is the 10.6, 10.0 eV magnesium fluoride windowed lamp filled with
Krypton. Resonance's lamp has a hard glass seal allowing high temperature processing, a special low fluorescence grade
of magnesium fluoride with very high VUV transmission and a high capacity chemical getter. The combined effect of these
advanced construction methods is the production of a lamp with very high spectral purity and exceptional operational and
shelf life. These lamps are similar in construction to those in use on the Hubble Space Telescope, which meet the
requirements of a 10 year mission life in the rigorous thermal environment of space.
During use the lamp may appear to drop in intensity due to an accumulation of photo polymerized deposits on the window.
These deposits result from the cross linking of organic compounds to form a thin UV-absorbing film on the window. These
films may be removed by a methanol wipe with a cotton swab or by a gentle polish with 0.3-micron aluminum oxide
powder. When the window cleanness is maintained the operational life of the Resonance lamps will exceed 2,000 burning
hours
Standard PID Bulbs Dimensions
Krypton VUV 10.0 eV VUV spectrum
Krypton VUV 10.6 eV VUV spectrum
