[UV SAFETY WARNING] New UVC filter for solar-blind imaging

[rfcurry]

[UV SAFETY] UV-C Light Is Dangerous

 

NEVER look at a UV-C light.

NEVER let UV-C light hit your skin or eyes directly or by reflection.

UV-C light can cause:

• severe burns of the eyes and the skin, and
• DNA damage from broken chromosomes.

When working with UV-C illumination, you MUST:

• cover up completely, 
• wear head & eye protection, and
• have strong ventilation.

---

 

 

While working to determine why my CuRB didn't reach into the UVC (I have determined that my old CuSO4 salts are contaminated), I decided to create a liquid filter for UVC use in solar-blind applications. I have named it the MaximumC. The MaximumC chart is below:

 

For those who want to eliminate the Vis and most of the NIR, but still retain much of the UVC, here is the MaximumC stacked with a ZWB1, 2mm thickness:
 

Regards,

Reed

[colinbm]

I like the UV A, B & C reach of this filter.
But how is the Visible & IR controlled for UV or UVIVF ?

 

[lukaszgryglicki]

Looks good, but with ZWB1 it barely passes 253.7nm mercury line and still has some IR leak, so for me ideal for UV-B (more IR blocking needed) but for UV-C a bit too low transmission and cutoff about 260nm... 

[Andy Perrin]

Lukas it might make sense to look at other options for stacking to block the IR and vis leaks. It might be that some other thickness or glass combo will do a better job.

[lukaszgryglicki]

I know, but I'm just commenting on this particular one that it looks really good for UV-B, but not for UV-C (at least for me) - I don't know any filter that I could add to this and get 222nm and 254nm while blocking IR at the same time.

It is still a very good option - just not for deep UV-C...

[Andy Perrin]

Quote

 I don't know any filter that I could add to this and get 222nm and 254nm while blocking IR at the same time.

Yeah, for those wavelengths it's hard. I think you need a source with less IR to begin with. (Don't ask me to name one!)

[rfcurry]

The UVC is a bear to filter. See what some find acceptable for UVC filters in the spectrum graphs attached. 

 

The production of crystals is prohibitively expensive, and the finished product is delicate and prone to dehydration, cracking, and other ills. However, we can enjoy the benefits of the crystals through use of metallic sulphate liquid filters. 

 

 

Potassium Manganese Nickel Sulphate Hexahydrate.pdf potassium-cobalt-nickel-sulfate-hexahydrate.pdf

[lukaszgryglicki]

I see, I still dream that you could make somethign like original chart for CuRB - it was *ideal* because it just blocked IR and some R while passing down to 220nm - so it was an ideal filter to add to ANY stack where you just want to block IR and keep all-UV.

With that one, I can construct anything I need.

 

[colinbm]

@ rfcurry Can we see a diabatic graph of the MaximumC stacked with a ZWB1, 2mm thickness please ?

[rfcurry]

Col,

 

Sure thing:
 

[lukaszgryglicki]

Good, really good, but unfortunatelly mercury 253.7nm line is rather strongly "blocked", 222nm KrCl excimer is blocked totally, while IR around 710nm is only OD4.