LOW-PRESSURE MERCURY LAMPS

A low-pressure mercury lamp (LP Hg lamp) is a highly efficient UV light source of short wavelength.
Classified as in the same group as fluorescent lamps or germicidal lamps, the main light emission is a 254nm line comprising an 185nm line of far shorter wavelength.
Quite unlike LP mercury lamps, the high-pressure mercury lamps (HP Hg lamp) irradiate lights of many wavelengths including a visible light.

APPLICATIONS

1. UV/Ozone Dry Cleaning, Surface Modification,
2. UV/Ozone Ashing, Photo CVD
3. Advanced Oxidation Water Treatment
4. Decomposition of refractory organic gases
5. Ozone generation and ozone decomposition
6. Ionization and de-ionization
7. Sterilization and induction of spawning of shellfish
8. Deletion of IC memory
9. Light source of measuring instrument

Fig 1. UV/Ozone Semiconductor Mold Cleaner	Fig 2. Grid shape LP Hg lamp with a vacuum flange, SUV40GS
Fig 3. A worker is mounting a grid shape lamp of EUV200G to a surface processor.	.Fig 4. An advanced oxidation water purifier. 8 lamps are installed in a reactor.
Fig 5. Light source, EUV200USx14pcs, and Conveyor.	Fig 6. Water sterilizer, SUV110x2pcs.Lamp Shape & Model

Lamp Shape & Model

Fig 7. From top to bottom, N shape, U shape, W shape and a straight tube type LP Hg lamp	Fig 8. A double tube type lamp at front, UVL20P, is used for a photo-chemical experiment.

We have more than 100 lamp types and so have put model marks on them for a smooth product management.
Each sign included in the model marks has an implication interpreted briefly as below.
When you place an order for our lamps, please indicate a model mark including the end number after a hyphen. Regarding the numbers of 40, 70, 90 and 110, be careful that they differ from actual wattages.

Relative Spectral Energy Distribution of Hg lamps

Table of LP Hg lamp

1. Standard output LP Hg lamps
2. High output LP Hg lamps
3. Low output LP Hg lamps
4. Ultra-high output LP Hg lamps
5. Cold cathode lamps

1. Standard output LP Hg lamp

A most popularly used low-pressure UV lamp.
This lamp is based on a standard close to the global standard for low-pressure mercury lamps made in Europe and the United States.
However, the Japanese specifications supercede the Western ones in performances.
It is used for water treatments, UV/Ozone cleaning and/or ozone generation.

Table 1. Characteristics of standard output class lamps

Table 2. Applicable power supply

High output LP Hg lamps

Today surface processing centered by photo cleaning is the major application in most cases.
They expect that it will become the major light source also for photo oxidation water treatment (accelerated oxidation water treatment) in the future.
Japan is and will be dominant in this category of specifications.
As a forced cooling is required, experiences are necessary to design lighting fixtures.
Since the ultraviolet radiation playing the major role for surface processing is a 185nm line of low-pressure mercury lamp, you cannot expect high efficiency without a synthetic quartz for surface processing lamp.
There are so many different types in EUV Series depending on purposes of use that please consult with our sales staff for details.

Table 3. Characteristic of high output class lamps

Table 4. Applicable power supply(Ballast)

3. Low output LP Hg lamps

It is a hot-cathode type low-pressure mercury lamp of small scale, suitable for a miniature water sterilizer, ozonizer and memory deleting device.

Table 5. Characteristics of low output class lamps

APPLICABLE POWER SUPPLY

You can turn on the light with the closed-switch type ballast of fluorescent lamp.
A lamp is connected with the intermediate connector of lamp cord. A specific holder is required.

4. Ultra High Output LP Hg lamp

Table 6. Characteristic of ultra high output class lamps

Cold-cathode Lamp

Cold-cathode lamps are the same sort of the back lights of liquid crystal display units or neon signs.
They are characteristic in their long life although they are neither so efficient nor capable for a large wattage.
They are popularly used as a light source for generating ozone and monitoring water quality or ozone concentration.

Table 7. Characteristics of cold cathode lamps

Applicable power supply and lamp holder

Quality of bulb material

We use three kinds of silica glass, ordinary fused quartz, ozoneless quartz and synthetic quartz, of which features are mentioned below.

1. Ordinary Fused Quartz (H)

Produced by fusing natural quartz. It is so typical that when we call just silica glass it means this sort of fused quartz. Its permeability below 200nm is not so high. We identify this material as H.

2. Ozoneless Quartz (L)

It is a silica glass produced with heavy metals added to fused quartz, allowing no permeability of ultra-violet radiation of 200nm or less wavelength.
As ozone gas is harmful to human health, this material is used for germicidal lamps for indoor use.
As the ultraviolet radiation of short wavelength has also a sterilizing power, it is not necessary to use an ozonefree lamp intentionally to sterilize water. We identify this material as L.

3. Synthetic Quartz(S)

Synthesized chemically from silica compounds, it is a extremely high purity silica glass.
As there is no impurity, it excels in photo permeability. Its price is four times higher than that of fused quartz.
It is used as the light source for UV/Ozone surface processing where a 185nm wavelength works dominantly.
It also has a superior ozone generation capability, but the lamp is so much expensive that it is scarcely used for other purposes than surface processing. We identify this material as S.

CLASSIFICATION OF LOW-PRESSURE MERCURY LAMPS BY SURFACE LOAD

As the amount of ultraviolet radiation varies depending on a tube-wall temperature in low-pressure mercury lamps including fluorescent lamps, it is necessary to obtain an optimum temperature for lighting so that the maximum output can be attained, and also to regulate temperatures during operation.
Now that the tube-wall temperature is varied by a surface load, there is a method to classify fluorescent

Table 8. Classification of low pressure mercury lamps by surface load

lamps and the low pressure mercury lamps based on surface load.
The classifying method for low-pressure mercury lamps made of silica glass has so far followed that for fluorescent lamps.
However, there has been so much progress in the efficiency and so many types of silica glass low-pressure mercury lamps that the conventional method for fluorescent lamps can no longer cover all of them.
We, therefore, are proposing a classifying method as shown in the following table.

Table 9. Classification of fluorescent lamps