Ultraviolet

© Brooke Clarke 2015

Background
Description
Sources
Sensors
Object
Related
References
Links

Background 

This web page is part of my interest in optics and light. When optics is combined with electronics you get electro optics.

Description

Ultraviolet light (Wiki) has a wavelength shorter than visible violet light (Wiki, 400 nm) and longer than X-Rays (Wiki, 100 nm).  Atmospheric absorption stops the shorter vavelengths from getting to the earth's surface, but the longer (near violet) wavelengths do get to earth can cause sun burn.
Table from Wiki Subtyypes

name
WL nm
Notes
UVA 315 - 400
Long wave black light
UVB 280 - 315
Medium wave mostly absorbed by ozone layer
UVC
100 - 280
Short wave, germicidal, completely absorbed by the ozone layer and atmosphere

Sources

For general information about various sources of light see my lights web page.

Sun [Wiki plot altitude vs. altitude (ozone)] - being a black body (Wiki), as are filament lamps, the sun emits UV radiation, but the atmosphere does not pass all of it.

Incandescent light bulb (Wiki) - and especially Halogen lamps (Wiki) because the quartz bulb passes UV, but even a normal filament lamp but with a quartz bulb will make a useable UV source.

UV Filament Lamp

UVGTL3 8310 E17 Edison base 10.5 V 0.3A 253.7 nm
I think the 6 Watt mark on the box is my typo and should have been 0.6 Watt.  i.e. 10V @ 0.3 A is 3 Watts input so the UV output will be way down from that, such as 0.6 Watts.

UV Lamp UVGTL3 10.5 V
              0.3A 259 nm
This is not Wood's glass (Wiki) since it appears clear.

TigerUV 790 UV

New in carry case with goggles and extension coard + spare 160W 120 VAC lamp.
Sirchie TigerUV 790 UV

Sirchie web page for the 790UV - Alternate Light Source (ALS) - "A wide beam of 365nm UV light is useful to scan large areas for evidence at the crime scene. Evidence such as fibers, bone fragments, physiological fluids, and others can fluoresce in the presence of UV light, uncovering what was hidden without it."

Mercury-vapor lamp

 (Wiki) - typically high pressure tubes.

Fluorescent lamp

(Wiki) -

low pressure Gas Discharge Lamp

 mercury-vapor gas-discharge lamp where in normal lamps the inside of the glass tube is coated with phosphers (Wiki) that are excited by the UV light and radiate visible light.  But a UV fluorescent lamp has no phosphers and sometimes is made from a glass that transmits UV light better than common glass.

LED

(Wiki) - Near UV (375 - 395 nm) are commoonly available for low cost, but the shorter wavelengths (down to 240 nm) cost a lot more and are used for things like Alternate Light Source (Wiki: ALS) applications like viewing crime scenes.  Experimental LEDs at 210 nm are in labs.

Halogen Desk Lamp

Halogen Desk Lamp UV Filter Halogen Desk Lamp
Off: 0.001 mW/cm2
On: 0.019 mW/cm2
On-w/oGlass: about the same?
glass marked: UV Filter-001
sometimes reads 0.010 and other times 00.1 (suto ranging)
00.26 mW/cm2 (max w/glass UV filter)
00.48 mW/cm2 w/o glass UV filter

Sensors

International Light Technologies Model IL1400A Radiometer/Photometer with SSL001 Slim UV Probe & CC500 cCarry Case

There are different models, this one is the origional button keypad version (IL1400A manual). 

SSL001 UVA Super-Slim Probe (PCB photoresist exposure is common application)
Dynamic Range: 1.11e-5 to 9.00e-1 W/cm² (limit exposure to prevent heat damage).
Spectral Range: 260 - 400 nm.
Dimensions: 29 x 38 x 2 mm

The SEL623 and SEL624 are thermopile sensors with very broad wavelength ranges.

IL1400A Fig 1 - 4 AA Batteries
International Light Technologies Model
                      IL1400A Radiometer/Photometer with SSL001 Slim UV
                      Probe & CC500 cCarry Case
IL1400A Fig 2 SSL001 Slim UVA Probe (375nm peak)
International Light Technologies Model
                      IL1400A Radiometer/Photometer with SSL001 Slim UV
                      Probe & CC500 cCarry Case
IL1400A Fig 3 Afternoon Sun Oct
1.36 mW/cm2
International Light Technologies Model
                        IL1400A Radiometer/Photometer with SSL001 Slim
                        UV Probe & CC500 cCarry Case

Flame Detector Tube

The 155UG tube is offered on eBay.  These are used in countries with 220 VAC mains voltage as flame detectors.

Objects

Things to look at with a UV light.

Rocks

This application goes back many decades, the oldest UV light I have is from my father's interest in rocks and minerals.
Geology.com has a web page about this.

Aircraft Panel Instruments

In highshool I was in the Air Scouts and we met at Moffett Field.  They had Link Trainers (Wiki) that were fixed to the floor and about 30 feet long.
There was a cockpit and a teachers console.  The instrument lights were UV and the markings and needles were phospherescent.  That way a piolet preserved his night vision while still being able to easily read the instrument.  There are some photos taken using UV light on my Aircraft Clocks wer page.

Laundry & Other Whitners

One way to make a whiter white is to add phosphers so that the UV from the sun will not only reflect white light but also cause the phospher to glow white.
Some of the paper IDs in my wallett have whitners as part of their design.  Maybe to make counterfit versions easier to spot.

Money Related

The paper money of most countries has a number of features designed to make counterfiting more diffucult and to allow automated bill acceptors to correctly recognize the value of a bill even when the physical size of the bills are the same.

Charge cards often have a UV appearance that differs from their white light appearance.

Drivers License

My California DL has two photographs, the large white light viewable photo and a smaller UV only version.

Related

Optics
Electro Optical Gadgets
Lights

References

How Hot Are Your Rocks? Radioactivity in Uranyl-Activated Fluorescent Minerals - combines radioactivity and UV - Facebook: Fluorescent Minerals - including uranium glass

Links

PRC68, Alphanumeric Index of Web pages, Contact, Products for Sale
Page Created 24 Oct 2015