UV mercury lamps for surface treatment 185nm and 254nm

SEN Lights is represented in Europe by
Crystec Technology Trading GmbH

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UV lamps from Senlights

SenLights offers UV lamps with a high yield of short wavelength. The described lamps are dedicated for

For first time customers, those lamps are only available as a set together with lamp holder, reflector and power supply. Single lamps are only sold as spare parts.


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.

UV lamps overview


  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
uv ozone semiconductor mold cleaner SUV40G
Fig 1. UV/Ozone Semiconductor Mold Cleaner Fig 2. Grid shape LP Hg lamp with a vacuum flange, SUV40GS
light source and conveyer water sterilizer
Fig 3. Light source, EUV200USx14pcs, and Conveyor. Fig 4. Water sterilizer, SUV110x2pcs.
Lamp Shape & Model

Lamp Shape & Model

N, U, W shape lamps lamp for photo chemistry
Fig 5. From top to bottom, N shape, U shape, W shape and a straight tube type LP Hg lamp. Fig 6. 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.

Spectral Energy Distribution of Mercury lamps

UV spectrum
Fig. 7 Relative Spectral Energy Distribution of Hg lamps

Available types of low pressure mercury lamps

  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
Model Electric Rating Dimension UV Properties(254nm) Life(H)
Watt(W) Current (A) Tube Dia.(mm) Base Dia.(mm) Overall Length(mm) Emission length(mm) Total Output UV Power at 1m(µW/cm2)
SUV40 25 0.435 18 22 530 380 7 90 8000
SUV40U (25) 0.8 18 22 275 200 7 90 6000
SUV40G (25) 0.8 18     66*70     4000
SUV70D 50 0.8 18 22 730 580 13 150 6000
SUV90D 65 0.8 18 22 1030 880 17 210 7000
SUV90U (65) 0.8 18 22 530 453 17 210
SUV110D 95 0.8 18 22 1250 1100 24 240 8000
SUV110U (95) 0.8 18 22 640 563 24 240 8000
SUV110N (95) 0.8 18   400 300*60    
SUV110W (95) 0.8 18     270*95     7000
SUV110G (95) 0.8 18     160*160    
SUV110P-23 (95) 0.8 18   270 70*110     8000

Table 2. Applicable power supply
Ballast Lamp Electric/Electronic Remarks
UV41RC10 SUV40 Electric Input 100V only
SEU110 SUV110 Electronic  

2. 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
Model Name Electric Rating Dimension UV Properties (254nm) Life(H)
Watt (W) Current(A) Tube Dia.(mm) Base Dia.(mm) Overall Length(mm) Emission length(mm) Total Output(W) UV Power at 1m(µW/cm2)
EUV200D 200 1.4 18-20
1650 1500     5000
EUV201D 200 1.4 22 22.3 1650 1500     5000
EUV200U 200 1.4 18-20   815 730     5000
EUV200N 200 1.4 18-20     490*68     5000
EUV200W 200 1.4 18-20     340*96     5000
EUV200G 200 1.4 18-20     218*218     5000
EUV250D 250 1.4 18-20   2020 1870     5000
EUV250D 250 1.4 22 26 2020 1870     5000
EUV250U 250 1.4 18-20   1010 925     5000
EUV250N 250 1.4 18-20           5000
EUV250W 250 1.4 18-20           5000
EUV300U 300 1.4 18-20   1195 1110     5000
EUV300N 300 1.4 18-20           5000
EUV400D 400 1.4 18-20   3150 3000     5000
EUV400U 400 1.4 18-20   1565 1480     5000

Table 4. Applicable power supply (Ballast)
Ballast Lamp Electric/Electronic Remarks
UV201RC10/20 EUV200 Electric 100V/200V is not convertible

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
Model Name Electric Rating Dimension UV Properties (254nm) Life(H)
Watt (W) Current(A) Tube Dia.(mm) Base Dia.(mm) Overall Length(mm) Emission length(mm) Total Output(W) UV Power at 1m(µW/cm2)
UVL6D 6 0.147 15 19 230 130   1.1 5000
UVL6UH2 (6) 0.162 10 29.5 72 40   3.3 5000
UVL8D 8 0.17 15 19 280 170     5000
UVL10D 10 0.23 15 19 320 200     8000
UVL15D 15 0.3 18 22 360 250 4.2 33 8000
UVL20D 20 0.375 18 22 420 280 5.6 50 8000
UVL20U (20) 0.375 18 22 215 140 4.5 50 5000
UVL20P (20) 0.375 22 24 170 120     3000


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
Model Name Electric Rating Dimension UV Properties (254nm) Life(H)
Watt (W) Current(A) Tube Dia.(mm) Base Dia.(mm) Overall Length(mm) Emission length(mm) Total Output(W) UV Power at 1m(µW/cm2)
FUV400U 400 4.0 20   660 500     1000

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.

lamp shape

Table 7. Characteristics of cold cathode lamps
Model Name Electric Rating Dimension UV Properties (254nm) Life(H)
Watt (W) Current(A) Tube Dia.(mm) Base Dia.(mm) Overall Length(mm) Emission length(mm) Total Output(W) UV Power at 1m(µW/cm2)
SP3-2 (3) 15 6.5 9 85 25   1.1 8000
SP5-2 (5) 15 6.5 9 110 50   3.3 10000
SP6-2 (10) 12 6.5 9 160 100     10000
SL5DH (5) 15 8 7.5 117 70     10000
SL5UH (5) 15 8 24 61 33     10000
SL10UH2 (10) 22 6 29 232 197   21 10000
power supply and lamp holder
Fig. 8 Applicable power supply and lamp holder

Quartz 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.

quarz permeability
Fig. 9 Different silica glass shows different UV light permeability

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.


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 lamps and the low pressure mercury lamps based on surface load.

Table 8. Classification of low pressure mercury lamps by surface load
Classification Mark Description Tube-wall load
(W/cm2) (W/cm)
Low Outputclass UVL The same rating as the standard type Fl lamps, represented by commercial germicidal lamps. Developed by GE/Philips in 1938 and introduced into Japan. Toshiba, etc. put it in the market. 0.05 approx. 0.4 approx.
Standard output class SUV Developed in Japan in later 1970s, as a high grade germicidal lamp to sterilize ultra pure water used to clean silicone wafers and chips. Natural air-cooling and indoor lighting possible. 0.14 approx. 0.8 approx.
High Output class EUV Designed to increase a UV output per unit length. Forced cooling is required. Developed in place of the ultra-high output lamp which had already been in the market. A representative surface processing lamp for cleaning or activation. 0.21 approx. 1.6 approx.
Ultra-high Output class FUV Developed by BBC (Now ABB/Swiss). Intensive forced cooling is required. Despite its intensive UV power, this lamp is disappearing from the market for economical reasons including life expectancy . 0.60 approx. 5.0 approx.

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
Classification Description Tube-wall load (W/cm2)
Standard class Designed to achieve an optimum tube-wall temperaturein the vicinity of the standard lighting conditions. (Ambient temperature at 25C, Humidity at 65% or lower) 0.03 approx.
High Output class Designed to increase a photo output per unit length. 0.05 approx.
Ultra-high Output class Designed to increase further a photo output per unit length and contrived to keep mercury vapor pressure under control. 0.09 approx.

Crystec Technology Trading GmbH will be pleased to further discuss details with you.
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