Lighting Design - Science topic

Hello dear Sumit Bhowmick, good time,

Thank you for your time and information.

Piotr Garbacz previously reviewed the use of UV backlight in the "INSPECTION OF TABLEWARE GLASS PRODUCTS AT THE HOT END OF PRODUCTION LINE" paper and concluded that "Industrial trials have shown that this method cannot be used due to the significant reduction of the fluorescence effect with increasing temperature".

I want to use visible or infrared backlight but I don't know, which one is better!?

BR.

after LED irradiated the beam width increase , and intensity decreased

Please share me the best answer might you get...

For lighting, I think the best software is DIALux.

Search "DIALux" to find the official site and download the software.

I kjnow that exists DIALux EVO to, ut I never used this one.

Thank you everyone for your answers! Very helpful.

To follow up on Christophe Martinsons's statement that "UGR is not defined for light sources with an angular size less than 0.0003 sr," we have developed a simple model for predicting discomfort glare from outdoor lighting, which usually involves "small" light source. It uses illuminance quantities as these are generally easier to predict using lighting calculation software, and the luminances of backgrounds in real-world scenes are often highly non-uniform. Subsequent work showed that we also had to account for the maximum light source luminance if the source subtended an angle of 0.3 degrees or larger. The model uses the de Boer scale of visual discomfort, a 9 point scale from "just noticeable glare" to "unbearable." A decription of the model can be found online at: http://www.lrc.rpi.edu/programs/solidstate/assist/pdf/AR-DiscomfortGlare.pdf

Color rendering index (CRI or Ra) was defined and scaled using the equation above provided by Shigeo Kubota so that a "warm white" fluorescent lamp (with halophosphors, not a modern "warm white" fluorescent lamp) would have a CRI or Ra value of 50. Since the Ra value is linearly scaled based on the amount of chromaticty deviation, it can produce negative values. So an Ra of 100 implies no chromaticity shifts relative to the reference blackbody/daylight source, an Ra of 0 implied shifts twice as big as an Ra of 50, and an Ra of -50 would imply shifts three times as big as an Ra of 50.

Regarding daylight glare metrics, this paper is recommended:

 Kevin Van Den Wymelenberg & Mehlika Inanici (2015): Evaluating a New

Suite of Luminance-Based Design Metrics for Predicting Human Visual Comfort in Offices with Daylight, LEUKOS, DOI: http://www.tandfonline.com/doi/full/10.1080/15502724.2015.1062392.

Don't consider only the LED lamps but the whole luminaire, the way you will use it and the result on the road.

You will make more savings considering more than the LED lamps!

I build greenhouses and sunspaces in the pacific northwest.We have long cool grey winters and it is common for people to experience depression during this time. When given access to a sunspace with lots of natural daylight these symptoms seem to be greatly reduced.

I absolutely agree with Mario and his perspective on the building envelope. There's a good book on this subject with the title "Intelligent Skins" by Michael Wigginton and Jude Harris. Hope it helps.

Thank you Noël and Jacopo.

Noel : I agree about the restrictions of the notion of BRDF. But, it is still a very comprehensive parameter, that would need to be coupled with texture to give a full understanding of the reflection of an incident wave of an arbitrary surface. I am more interested in measuring BRDF without using conventional equipments (complex mechanical goniometers)...

Jacapo : the idea is to have a device that would reflect or transmit an incoherent light beam (emitted by an LED for instance) with a given angular distribution (a single lobe or a combination of several lobes), without mechanical equipment (no scanner, no moving prism, no variable lens, etc.). Ideally, the light would be broadband in the visible range (white light) but coloured LED would be fine too (5 to 10 nm wide).

The concept would be somehow similar to a controlable light diffuser. I have never used SLM so far. Are you aware of such applications of SLM ?

Christophe