I am sorry, my last posts, was considered as spam. I deleted them already.
So, I will not post any links to products anymore unless you will ask me, and then I will send you links as a private message.
Basically, my first idea was proposing to buy LED strips for IR, Ultraviolet and growing plants LEDs.
But then I came up with an even better idea.
If you have some basic skills in electronics and soldering you can build a simple test stand using set of leds with different narrow emission characteristics like red color (620nm), yellow (590nm) etc.
Different LED has different voltage drop, but it’s easy to power them properly with adding correct resistor. All LEDs can be powered using whatever DC source you have, for example 12V, I can help with a circuit if you need. And you may add a button or rocket switch to turn on/off the power.
You may even connect all leds in parallel simultaneously and add switch for each led and switch on/off without assembling/disassembling the test stand. In this way you may test a few light on LEDs.
And yes, as you have professional spectrometer you will check LED characteristics first and then calibrate LM4 algorithm.
For ultraviolet I am personally going to use 275nm LED which is perfect for disinfection/sterilization but it’s not healthy spectrum for eyes so you probably need protection glasses working with this particular LED which cuts light emission 180-520nm, I have this one.
As an alternative to test you may find on Amazon near ultraviolet 390-400nm strip, it seems less like harmful light for eyes.
I have no much experience with infrared lights, but I believe that having in the test toolbox something like this 940nm strip will also may improve the algorithm quality.
I hope it helps.
and sorry for a little bit of mess I made with several answer messages.