78-2046-0.75T Jelight Low Pressure Mercury Vapor Ozone Producing Double-Bore Lamp

The Jelight 78-2046-0.75T Low Pressure Mercury Vapor Ozone Producing Double-Bore Lamp features primary irradiance in the Ultra-Violet region of the electromagnetic spectra. About 90% of the emitted UV radiation is at the 254 nm mercury resonant line. The spectral width of the 254 nm line is 1Å (0.1 nm).

This lamp produces ozone by generating effective source of 185 nm spectral line (65% transmission) which is absorbed by oxygen molecules. Also, ozone absorbs 254 nm UV radiations and breaks down to oxygen molecules and atoms. Using a spectrometer, mercury spectral lines can be observed at: 184.9 nm, 253.7 nm, 296.5 nm, 302.2 nm, 312.6 nm, 313.2 nm, 365.0 nm, 365.5 nm, 366.3 nm, 404.7 nm, 435.8 nm, 546.1 nm, 577.0 nm, and 579.0 nm.

The amount of ozone generated by the lamp depends on the following: intensity of 185 nm UV radiation, intensity of 254 nm UV radiation, type of circulating media gas during operation, flow rate of the media gas, and the dimensions of the ozone generator chamber. By operating the lamp in oxygen free environment such as nitrogen or argon atmosphere enhances the intensity of 185 nm UV radiation.

Supplying higher current ratings than recommended (20 mA) will result in shorter lifetime. Although the intensity of spectral lines with longer wavelengths will be increased, at the same time, the intensity of spectral lines with shorter wavelengths will be decreased, and the lamp temperature will also become higher than normal.

The output stability is able to be improved by shielding the lamp from RF fields and operating with steady power supply. Also, higher frequency from secondary voltage enhances the stability.

The average lifetime of the lamp when operating under DC mode is reduced by factor of two. The reason is that one electrode (cathode) operates at 100% duty cycle. In DC mode, the mercury inside the lamp tends to migrate away from the cathode. This causes a fluctuation on the output, depending on specific portion of the lamp evaluated at specific ranges of wavelength. The total visible length of the mercury plasma arc is 4 inches.