This web page is part of my interest in optics and light. When optics is combined with electronics you get electro optics.
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 wavelengths 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
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
For general information about various sources of light see my lights web page.
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.
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.
This is not Wood's glass (Wiki) since it appears clear.
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."
Wiki) - typically high pressure tubes.
Grimes AN-3038-1 aka C-5 (see Electro Optic Gadgets)
ercury-vapor gas-discharge lamp where in normal lamps the inside of the glass tube is coated with phosphors (Wiki) that are excited by the UV light and radiate visible light. But a UV fluorescent lamp has no phosphors and sometimes is made from a glass that transmits UV light better than common glass.
Wiki) - Near UV (375 - 395 nm) are commonly 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
Off: 0.001 mW/cm2
On: 0.019 mW/cm2
On-w/o Glass: about the same?
glass marked: UV Filter-001
sometimes reads 0.010 and other times 00.1 (auto ranging)
00.26 mW/cm2 (max w/glass UV filter)
00.48 mW/cm2 w/o glass UV filter
J-221 long wave (300 to 400 nm) meter: 0 to 12 & 10 to 60 uW/cm^2 - typically used for blacklights (Wiki).
J-225 short wave(230 to 270 nm) meter: 0 to 24 & 10 to 120 uW/cm^2 - typically used for germicidal (254 nm) lamps.
Yellow Filter No. 50107: removes all UV light leaving only IR light. To get a UV only reading Subtract 1.06 * Yellow filter reading from the no filter reading.
UV [only] = No Filter reading [UV + IR] - 1.06 * (Yellow Filter reading) [IR reading corrected for filter loss]
The yellow background on the meter face contains a phosphor that glows after UV exposure.
Has two meter ranges: 0 to 12 uW/cm^2x100 and 10 to 60 uW/cm^2x100
26 April 2019 outside around 3pmmeter reads 14 on B range w/o yellow filter, and meter reads 7.6 with filter. To get final reading multiply meter by 10.
So the direct Sun is1400 uW/cm^2 and through the yellow filter the Sun is 760 uW/cm^2.
International Light Technologies Model IL1400A Radiometer/Photometer with SSL001 Slim UV Probe & CC500 cCarry CaseThere are different models, this one is the original 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
IL1400A Fig 2 SSL001 Slim UVA Probe (375nm peak)
IL1400A Fig 3 Afternoon Sun Oct
Things to look at with a UV light.
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.
In high shool 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 phosphorescent. That way a pilot preserved his night vision while still being able to easily read the instruments. There are some photos taken using UV light on my Aircraft Clocks web page.
One way to make a whiter white is to add phosphors so that the UV from the sun will not only reflect white light but also cause the phosphor to glow white.
Some of the paper IDs in my wallet have whiteners as part of their design. Maybe to make counterfeit versions easier to spot.
In the movie Revolver (IMDB) Ray Liotta's character is naked in a tanning room and his teeth just shout light.
The paper money of most countries has a number of features designed to make counterfeiting more difficult 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.
My California DL has two photographs, the large white light viewable photo and a smaller UV only version.
There are additional markings only visible under UV light.
Uranium Glass (Wiki)
Most items that glow in the dark also glow brightly under UV light. This is a good way to "charge" them.
How Hot Are Your Rocks? Radioactivity in Uranyl-Activated Fluorescent Minerals - combines radioactivity and UV - Facebook: Fluorescent Minerals - including uranium glass
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Page Created 24 Oct 2015