1. LUMEN METHOD E= N x n x ø x UF x MF A
where MF = LLMF x LSF x LMF x RSMF
E =Maintained illuminance, lux
A = Area, m2
Ø = Initial lamp flux, lumen
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MEBS6002

2. LUMEN METHOD
Utilization factor Ratio of flux received by reference plane to total rated lamp flux in the installation.
Maintenance factor –
-- LSF
-- LLMF
-- LMF
-- RSMF
K. F. Chan (Mr.)
MEBS6002

3. K. F. Chan (Mr.)
MEBS6002

4. K. F. Chan (Mr.)
MEBS6002

5. K. F. Chan (Mr.)
MEBS6002

6. K. F. Chan (Mr.)
MEBS6002

7. LLMF & LSF
K. F. Chan (Mr.)
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8. (Taken from Table 3.4 of CIBSE Code for Lighting, 2002)
K. F. Chan (Mr.)
MEBS6002

9. LMF
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10. LMF (Taken from Table 3.5 and 3.6 of CIBSE Code for Lighting, 2002)
K. F. Chan (Mr.)
(Taken from Table 3.5 and 3.6 of
CIBSE Code for Lighting, 2002)
MEBS6002

11. RSMF
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MEBS6002

12. RSMF (Taken from Table 3.7 of CIBSE Code for Lighting, 2002)
K. F. Chan (Mr.)
MEBS6002

13. K. F. Chan (Mr.)
MEBS6002