Dear Dr. Fox,

My research group is experiencing the same problem with our chamber. I think we have found the solution with a USB spectrometer for monitoring environmental parameters. In the link below you can find the equipment we're going to purchase. There are some accessories that you can purchase together with the spectrometer. I suggest the optical fiber with the cosine corrector.

Kind regards,

Thelma Machado

http://oceanoptics.com/product/usb2000-custom/

I recall as an undergraduate student in the 1980's designing and building my own instrument to measure the spectral output and intensity of light generated from a photobacterium! I used parts from a broken B&L Spectronic 20 and a chart recorder to measure and record the spectral output and created a simple light-box with Silicon Photo Detector to measure the light intensity over time (voltage output). IT worked well and got the job done.

Light Intensity and Spectral emission measurement are two different things. We often use two different detectors for this. Do you know what wavelength range will be needed, because you can build a setup inexpensively if you will only be testing in the visible region.

A benchtop spectrophotometer would need to have the existing light source "blanked" at the right time so the emitter (your LED) could be turned on. You would really just be using it for it's built-in diode array or CCD to capture the spectra. Depending on the model of spectrophotometer selected, this may or may not be easy to do.

You could also purchase an inexpensive sensor such as the Spark spectral sensor (380-700 nm). Any plotting software could be configured to map the data and form a spectral chart.

People have even developed methods to use a Smart Phone as a spectrophotometer too. Lots of examples on the web.

Dear collagues, your answers seem to be spot on! I was hoping I could just place my LED inside the spectrophotometer chamber and measure the parameters. I will look into this model suggested by Dr Thelma as an option as mentioned by Letter above! Also will consider the apps, but I am afraid it is largely dependent on the mobile's CCD quality thus potentially not trusted by my peers. 

I will then move into looking into the building possibilities also suggested by Letter though I'm afraid I may be too naive in the technical parts to build myself one alone. 

I have been thinking and maybe some smart mates from Hackuarium in Lausanne ma have a good idea http://hackuarium.strikingly.com/ or even available blueprints!

Thanks much! 

Ola Fox, nesta não posso te ajudar, pois não temos estes aparelhos por aqui.

Abcs.

Antonio

This is not my field.

you can try an intergrating sphere,

those can give you a lot of data on radiometry, spectrum' photometry - the whole thing

 Hello Arie, This sounds like an interesting suggestion. However I am not sure how easy it would be finding such nice equipment. Also, it looks like data interpretation will depend on expert knowledge? I will look into it, thanks!

there are some really nice ones out there - not all of them expensive - with detectors that connect to a computer and give you a lot of data.

you get graphs with the wavelength, color temperature, intesity, power etc.

you get the numerical values as well as the graphs, of course.

at the end everything is somewhat dependent on expertise, but these are things you can read about on wikipedia and understand pretty well.

I saw the about radiophotometer set-up and principles, it seems like a tough solution for commercial MEMs optical Sensors.

I came across a handheld device on Gigaoptics and some other company working on the same thing.

http://led-measurement.com/BTS256-LED-tester/

BTS256-LED Measurement Tester

https://oceanoptics.com/application/led-measurement/

Can Angle of refraction and path-length yield useful information on wavelength of optical spectrum ?

Refractometers or simple detectors can be used, but the issue with using refractometer is the medium must be ideally more responsive to the light with higher medium of index and with less lossy.

This will yield a good information, but again the information can be precise to the wavelength and dispersion due to wavelength-mix cannot be avoided

Is it possible to use spectrophotometer? For example, by covering the light source and light up the LED in sample compartment?

Dear colleagues.

I have the same problem and I don't know how to fix it!

we do not access to spectrometer and we want to determine our wavelength of red:blue and white treatment. However two of my light treatments are monochromatic Blue with the wavelength of 460nm (according to it's catalog) and Red with the wavelength of 620nm.

first, I want to know that if I can calculate the wavelength of my R:B treatment by wavelength of each diodes.

second, I want to know that if there is a way to calculate the wavelength of white treatment without using spectrometer.

Hi dear Eduardo Goncalves Paterson Fox

you can mesure led nm and intensity with Spectrometer (Color Meter) cekonic 700 or 7000

some of Description about the device

The Sekonic SpectroMaster C-700-U is designed for motion and still image captures who must produce quality results with proper subject color while working with multiple types and brands of light sources. A full-spectrum color meter, the C-700-U can precisely measure LED, HMI, Fluorescent sources, new-style plasma lamps as well as tungsten lamps, natural light and electronic flash. Its high-resolution measuring system, featuring CMOS sensor, capture and displays spikes in light source output to provide unsurpassed color measurement accuracy.

The C-700-U's large, color touch screen displays light-source information as a color spectrum graph that is expandable for closer inspection, CRI (Ra plus R1 to R15), Kelvin (correlated color temperature), Illuminance (footcandle or Lux) and light source filtration values in Mired, CC index as well as filter correction values for major light source and lens filter brands. Its “Multi Lights” display enables quick data comparison of four lights with full data on each at the touch of a finger. Its “Multi Spectrum” mode enables displaying spectral graphs of three sources for quick visual comparison.

Different than any spectrometer today, the C-700-U meter not only displays more ways to view and compare light-source information, it also provides filtration information to correct and modify light color for cleaner recording and simpler post process.

https://www.sekonic.com/united-states/products/c-700-u/overview.aspx

I have an assignment to measure colored LED lamp with USB spectrometer from OceanOptics. Inc in the lab. When I am going to measure with color mode or irradiance mode it always requires to load reference file,at the moment I do not have any reference file.Would it be really necessary or should I have to great own reference? if so How?

Also do you know what is dark reference and light reference shown in the software?

Thank you in advance