Difference between Luminous flux Luminaire and Luminous flux Lamps

[Bushair]

Hello,
I would like to know the following the Difference between the terms Luminous flux (Luminaire) and Luminous flux (Lamps). I am getting conflicting answers to this question on the web.
For instance when I use the light fixture COOPER CROUSE-HINDS NVMV NVMVSxx15xo-G34-RD70, I see the following values:
Luminous flux (Luminaire): 12344 lm
Luminous flux (Lamps): 17500 lm
Is this something to do with the light loss ratio? Please clarify. Thank you

[T.Magenheimer]

Dear Bushair,

The following points should answer your question about how the two luminous flux for the lamp and the luminaire are calculated:

• 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.
• 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


Best regards,
Your DIAL Support Team