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ArcticMyst Security by Avery

LPM measure UVA>C optical power?

May 8, 2012
I know this is a bit off topic for the typical use of LPMs,

But I need to set up a variable intensity UVA-UVC source, using multiple LED diodes at discrete wavelengths, from ~400nm to ~280nm.
I do realize 280nm is the high-end of UVC, but the source in question doesn't need to go lower.

Maximum emission intensity will be about .4J/cm^2 (higher wavelengths), and I'm assuming an order of magnitude lower for the shorter ones (This is what I'm testing).

I won't be mixing the diodes, so there will be discrete bands of nearly monochromatic emission.

Would any LPM be sensitive to these <400nm wavelengths or are they all typically biased towards the usual laser emission wavelengths? Does anyone know of a LPM that would serve double duty as an actual laser measuring device, while still being sensitive to my initial query (because... well, I've got several laser diodes I'd love to measure as well!). The latter question is nowhere near as important as the former.

Any advice would be appreciated. And, full disclaimer, opinions are all I'm looking for. No human eyes or skin will be exposed to this UV light source, it's just for very preliminary measurements of a prototype device, without spending a fortune on certified <UVA measuring devices. Obviously < blue light sources are exposure hazards, I'm well aware of that, and proper measurements will be taken if prototyping is successful.

Thanks all!

Jun 19, 2010
I have a graphtec UV sensor.
I use a 3d printed sphere coated in UV reflective paint, and it's printed with a port for the sensor head and a port for the LED to sit 90deg off axis in the sphere from the sensor.

Then you need some known intensity source to calibrate your integration sphere loss%, or make all your readings qualitative relative to each other.


Jun 18, 2012
you need to correct for the quantum efficiency of the phosphor. It may not be as efficient at all wavelengths so you need a material with a known curve. Also the illumination may not be the same so you might want to measure straight on a phosphor on a glass slide and make sure the beam size is equal illumination. The sphere is an integrating sphere that should account for that.