Relatively cheap UV bandpass filters

[Stefano]

On eBay there are 222 nm UVC lamps such as this: https://www.ebay.com/itm/324525069997

 

Or here: https://www.google.com/url?sa=t&source=web&rct=j&url=http://www.uvebay.com/productinfo4686.html&ved=2ahUKEwj40dva1q3xAhV3_rsIHbBrBnoQFjARegQICBAC&usg=AOvVaw0YYI9pqUrw9zzhokNxly5R&cshid=1624448655625

 

They could be used together with the 225 nm filter, assuming it has good blocking. Something David would probably be interested in...

 

Also Jonathan's monochrome camera probably can see at least down to 200 nm.

[dabateman]

That second link looks super sketchy. Uvebay? Really?

But if true might be fun to play with. I was hoping for more affordable options after COVID. Still hasn't happened yet. The cost of Ozone bulbs skyrocketed. So I don't have any 185nm sources anymore.

I am not sure I would have a filter to take advantage of that light. I think our 254bp cuts off after that. My 193bp might work, as it trails out long. But 206nm would be better.

 

I still need a tight 206nm iodine lamp.

[colinbm]

That second link looks super sketchy. Uvebay? Really?

But if true might be fun to play with. I was hoping for more affordable options after COVID. Still hasn't happened yet. The cost of Ozone bulbs skyrocketed. So I don't have any 185nm sources anymore.

I am not sure I would have a filter to take advantage of that light. I think our 254bp cuts off after that. My 193bp might work, as it trails out long. But 206nm would be better.

 

I still need a tight 206nm iodine lamp.

 

Something is fishy....

I can smell a rat.....

http://www.uvebay.com/productinfo4716.html

[Stefano]

That's very cheap...

 

I found that website by searching 222 nm lamps. I don't know how reliable it is.

[JMC]

I bought one of the filter wheels from that guy along with a couple of other filters. The ones I got which were below 350nm had max transmission of 10-15%. The 258nm one had a leak at around 520nm. Not measured them above 800nm. Some of them were pretty corroded (oxidised) on the un-coated side. Not sure what I'll use them for yet, maybe a UVB/C sparticle.

 

The graphs.

 

 

Just a quick follow on, tested these out to 1100nm today. They all have good blocking (as in 'down in the noise' good).