A mini DIY integrating sphere: Possible

vizier87 · 2019-01-08T04:22:00.000Z

Hi guys, first post here after introducing myself.

I'm trying to design a human skin probe using an integrating sphere. But the ones that I know of are pretty bulky. The one I ended up with was the Avasphere by Avantes but I feel I could do better.

By photonics standards, say I attempt at building one as described in this link using a smaller ball (say with a 8 cm diameter), would it hypothetically be sufficient?

Thanks.

Vizier87

chadvone · 2019-01-08T06:37:45.000Z

How large is human skin prob?
What is the expected output?
Size of measuring meter?

djozz · 2019-01-08T07:15:29.000Z

You could do better than a high end commercial sphere and decide to DIY with paper mache. That makes me wonder what special features you are looking for? If you let us know that we may help out.

vizier87 · 2019-01-08T08:54:52.000Z

chadvone:

How large is human skin prob? What is the expected output? Size of measuring meter?

I expect an opening port with a 1 cm diameter, and the output is directly channeled to a spectrometer. The size is hopefully hand-sized, fitting my palm if it's only the sphere of course.

vizier87 · 2019-01-08T08:57:32.000Z

djozz:

You could do better than a high end commercial sphere and decide to DIY with paper mache. That makes me wonder what special features you are looking for? If you let us know that we may help out.

Really? Paper mache is better than Spectralon of Barium Sulphate? There has to be some sort of tradeoff there right?

The features, if I understood you right, is to get the most of the electromagnetic spectrum with a broad light source, like the one produced by a tungsten-halogen light. Simply, 200-2500 nm range.

Thanks bro. I appreciate the replies.

djozz · 2019-01-08T09:06:51.000Z

I think you misunderstood me. My question was: why do you not want to use the Avasphere integrating sphere, and instead make your own?

vizier87 · 2019-01-10T01:43:05.000Z

djozz:

I think you misunderstood me. My question was: why do you not want to use the Avasphere integrating sphere, and instead make your own?

My apologies. Yeah, I wanted to make my own monolithic module which is more flexible for my design. I want to have a built-in standard which can be programmed to automatically refer to it using electromechanical means.

So if it is small like a ping-pong ball and has acceptable accuracy, so much the better for me.

Has anyone tried this?

Thanks.

clientequator · 2019-01-10T18:10:52.000Z

If you make own light integrating sphere, what is the best method to calibrate? I am thinking that you use a known brightness source (say 500 lumen), but where do you find such a source of ‘reference brightness’ lamp? djozz, do you use a specific reference light to calibrate your tests? I would like to know what the best way is. Thank you sir!

contactcr · 2019-01-10T18:17:43.000Z

clientequator:

If you make own light integrating sphere, what is the best method to calibrate? I am thinking that you use a known brightness source (say 500 lumen), but where do you find such a source of ‘reference brightness’ lamp? djozz, do you use a specific reference light to calibrate your tests? I would like to know what the best way is. Thank you sir!

This thread has the answers you seek: WTS: Calibration lights for DIY integrating spheres / lumen tubes - 67 € -

vizier87 · 2019-01-11T02:56:59.000Z

clientequator:

If you make own light integrating sphere, what is the best method to calibrate? I am thinking that you use a known brightness source (say 500 lumen), but where do you find such a source of ‘reference brightness’ lamp? djozz, do you use a specific reference light to calibrate your tests? I would like to know what the best way is. Thank you sir!

The 100% and 0% references will be based on spectrometric readings with a tungsten-halogen light, which is pretty simple. I suppose the guys in this forum are more adapted to lumen meters. My range is wide, like 200-2500 nm wide.

vizier87 · 2019-01-11T03:01:08.000Z

contactcr:

This thread has the answers you seek: WTS: Calibration lights for DIY integrating spheres / lumen tubes - 67 € -

Thanks! That'll definitely add more info in what I need.