type of light set in .ies or .LDT

questions regarding the handling of DIALux evo. (features, tools, options, settings)
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deech123
Posts: 13
Joined: Mon Jun 10, 2013 12:31 pm

type of light set in .ies or .LDT

Post by deech123 » Thu Nov 30, 2017 6:12 pm

HI guys,

I have a question.
we have our own .IES files and .LDT files done in a professional lab.
but what we notice is that when importing one of the IES files or .LDT files, we see that the type of light is automatically set to LED.
for the other one the type is set to halogen lamps? how can we set the halogen lamp into LED.
since we all have LED lamps that has been tested in the lab.

any idea where to change that in the IES or LDT to set it correct when importing it into Dialux?

hope somebody can help us, since we searched for days, contacted the lab, but nobody seems to know how or where?

thx.

Csuleiman
Posts: 1048
Joined: Wed Mar 07, 2012 3:07 pm

Re: type of light set in .ies or .LDT

Post by Csuleiman » Fri Dec 01, 2017 8:50 am

Dear deech123,

The IES file you have is tested as relative photometry. This means the bare lamp (LEDs) have been tested before used in the luminaire.
The IES LM79 standard says that luminaires with LEDs should be measured as absolute photometry. In this case the luminaire has 100% LOR and the changes you want to do could be done directly to the luminaire data. Ask your laboratory if they can provide absolute IES files according to LM79.
Tell your laboratory to measure LED luminaires as absolute photometry, according to LM79. In this case the LOR is 100% and all luminous flux changes you do is luminaire luminous flux.

Normally photometric data as IES file from a LED luminaire it is tested according the IESNA standard LM79. This is not a must but in most cases this is a fact. The reason is that often relative photometry cannot be carried out with LED fixtures.

Relative photometry:
• The lamp and the gear is taken out of the luminaire and the luminous flux of the bare lamp is measured.
• The lamp and the gear is mounted in the fixture and the luminous intensity distribution of the fixture is measured. This measurement also gives a luminous flux of the luminaire.
• The luminous flux of the bare lamp is set to 100%. As normally (but not always) there is less light coming out of a fixture than it comes from the bare lamp, the luminous flux of the fixture is lower:
Light Output Ratio (LOR) [%] = luminous flux of the luminaire / luminous flux of the lamp

Absolute photometry:
• In some cases, the lamp cannot be taken out of a fixture. For example in a LED luminaire the housing is the heat sink for the LED. If you run the LED without the housing, the LED would be destroyed. In those cases the testing lab can carry out an absolute photometric testing. The LM 79 defines that for LED fixtures with LEDs that are not equipped with a socket (retrofits) absolute photometry has to be carried out. (This is only necessary in the US)
• The measurement is then carried out for the complete fixture. The luminous flux of the system is calculated. The LOR is not stated as it is unknown / undefined. In the IES file, the luminous flux is given as “-1” indicating that it is a absolute tested IES file.

Best regards,
DIAL Support Team

kvkozierowski
Posts: 296
Joined: Mon Mar 19, 2012 9:29 am
Contact:

Re: type of light set in .ies or .LDT

Post by kvkozierowski » Fri Dec 01, 2017 9:50 am

Hello deech123,

I am not sure what you mean with "type of light". If you mean the "lamp type":
lamptype.PNG
lamptype.PNG (13.14 KiB) Viewed 965 times
This information is not included in IES or LDT files and can be set in ULD files only. For IES and LDT files we try to guess the lamp type depending on the lamp name. If you use a ZVEI or ILCOS designation the chances are good that this guess is correct. As both shemes do not apply to LED lamps we set "LED" as lamp type if the lamp name/type starts with "LED".

To try this you can edit your ldt/ies and enter a lamp name starting with "LED".

Best Regards
Kolja

deech123
Posts: 13
Joined: Mon Jun 10, 2013 12:31 pm

Re: type of light set in .ies or .LDT

Post by deech123 » Fri Dec 01, 2017 10:10 am

well whatever I try with some of my IES files, it's not working.

i put LED in the filename.
I put LED in the luminaire number, in the file name(in LDT editor)
also in the lamps tab, i put type of lamps : LED SMD
whatever I put, dialux refuse to set this to LED automatically.

while other files work perfect... i'm blocked here what is going on.

any other suggestions?

D.

kvkozierowski
Posts: 296
Joined: Mon Mar 19, 2012 9:29 am
Contact:

Re: type of light set in .ies or .LDT

Post by kvkozierowski » Fri Dec 01, 2017 10:46 am

Hello,

Just had a look at the source.
Currently the lamp type is determined for ldt and ies files by:

1. absolute photometry => LED

2. from technical data:
lm/W
< 15 => Incandescent
< 30 => Halogen
> 100 & CRI < 30 => LowPressureSodium
> 100 & CRI < 50 => HighPressureSodium
> 100 & CRI >= 50 => LED
> 80 & CRI > 80 => MetalHalide

length < 0.6m & length/width < 2 => CompactFluorescent

3. From name:
...
empty or starts with "LED" => LED

This may change at any time. As I mentioned in my previous post: This information is not available in IES and LDT and we need to guess it, this will fail for some files, in this case the user needs to set the correct value manually in evo. However if you use absolute photometry files as Csuleiman said it will be considered as LED in any case.

Best regards
Kolja

deech123
Posts: 13
Joined: Mon Jun 10, 2013 12:31 pm

Re: type of light set in .ies or .LDT

Post by deech123 » Fri Dec 01, 2017 2:42 pm

well, whatever we do, it is not working.

I give it up, since there is no logical explanation why one file is exact the same,only lumen a bit higher and is taken as lamp type : LED
whey the other(s) are taken as Halogen lamps... they have both LED as lamp type, LED in the description of the file etc...

strange.

D.

kvkozierowski
Posts: 296
Joined: Mon Mar 19, 2012 9:29 am
Contact:

Re: type of light set in .ies or .LDT

Post by kvkozierowski » Fri Dec 01, 2017 2:49 pm

Hello,

The explanation is that the different lamps have typical lm/W values and these are used to guess the correct lamp type (see my previous post please).

Best regards
Kolja

deech123
Posts: 13
Joined: Mon Jun 10, 2013 12:31 pm

Re: type of light set in .ies or .LDT

Post by deech123 » Fri Dec 01, 2017 2:53 pm

so Kolja,

if I set LED or not, it's only the lm/w what is used to see if it's led.

my luminaires has lumen of 5600 to 29875lumen, and some are set as LED, some not.
seems there is no correct way to set it right away in Dialux.

maybe Dialux must check the lamp type in the next updates.
if the word LED is set in the LAMP type, then it must consider it as LED :-)

thx for your update and help.
always appreciate it if somebody gives answers. :D

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