[Radiance-general] RE: RE: I can't get even similar irradiance values from lamps.

[Minki sung]

Thank you for your comments. As only radiance(W/m2sr) or irradiance(W/m2)
values are being dealt with from modeling to results lamp color does not
make problem as Lars said and radiance value also has no problem as 0.032m
is diameter, which Lars might already know. But the aging of lamps might
need to be checked, that means all the conditions of experiment should be
checked again as the experiment was done at the field, in case there is no
problem in RADIANCE calculation.

Sung


Message: 3
Date: Mon, 16 Mar 2009 16:30:30 +0800
From: "Lars O. Grobe" <lars.grobe at nus.edu.sg>
Subject: Re: [Radiance-general] I can't get even similar irradiance
	values	from a lamp.
To: Radiance general discussion <radiance-general at radiance-online.org>
Message-ID: <49BE0E26.5000609 at nus.edu.sg>
Content-Type: text/plain; charset="iso-2022-jp"

Hi!

>> irradiance level on the surfaces of the box. The cylindrical lamps  
>> has 32mm in diameter and 540mm in length and The radiance of 44W/sr/ 
>> m2 calculated with the UV output of the lamps (7.5W) was applied to  
>> the lamps.

Hm, how did you calculate the 44W/sr/m2 for the lamps? I get
7.5/(2*pi*0.54*0.032)=7.5/0.1086=69W/m2, divided by pi=21.99 W/m2sr.
This means that your light source is two times brighter than I would
expect it to be.

CU Lars.
-------------- next part --------------
A non-text attachment was scrubbed...
Name: lars_grobe.vcf
Type: text/x-vcard
Size: 310 bytes
Desc: not available
Url :
http://radiance-online.org/pipermail/radiance-general/attachments/20090316/f
17a5681/lars_grobe-0001.vcf

------------------------------

Message: 4
Date: Mon, 16 Mar 2009 13:41:45 +0000
From: yijun huang <yijunhuang at hotmail.com>
Subject: ReE: [Radiance-general] I can't get even similar
	irradiancevalues	from a lamp.
To: <radiance-general at radiance-online.org>
Message-ID: <BAY120-W6907872794225EF13C778DB9B0 at phx.gbl>
Content-Type: text/plain; charset="gb2312"



Also, I'm curious how you'd use LAMPCOLOR for a UV-lamp? Obviously the
efficacy would not be the usual 179?

 

YC Huang
 

Message: 5
Date: Mon, 16 Mar 2009 22:51:48 +0800
From: "Lars O. Grobe" <lars.grobe at nus.edu.sg>
Subject: Re: [Radiance-general] I can't get even similar
	irradiancevalues	from a lamp.
To: Radiance general discussion <radiance-general at radiance-online.org>
Message-ID: <49BE6784.80702 at nus.edu.sg>
Content-Type: text/plain; charset=GB2312


>
> Also, I'm curious how you'd use LAMPCOLOR for a UV-lamp? Obviously the
> efficacy would not be the usual 179?
Well, it is probably not. But if you multiply the 7.5W to get the lumen
output, lampcolor will internally divide by 179 to calculate back to
radiometric values, so the result should be fine (as long as you do not
start to multiply the results of rtrace to get anything like lux or nits
from what is not visible light ;-) )...

One nice problem if comparing the result to experimental measurements
will be that the lamp's age will probably show some influence on the
real output. So most probably something like 7.5W*0.9 or 0.8 would be
more realistic. But I have NO experience with this UV stuff, so this is
something to find out first.

CU Lars.



------------------------------

_______________________________________________
Radiance-general mailing list
Radiance-general at radiance-online.org
http://www.radiance-online.org/mailman/listinfo/radiance-general


End of Radiance-general Digest, Vol 61, Issue 12
************************************************