An industrial workshop requires 300 lux of uniform illumination on workbenches. The area to be illuminated is 120 square meters. If the utilization factor is 0.7 and the maintenance factor is 0.8, what should be the total luminous flux provided by the lighting installation?
64286 lumens
Lighting design uses the lumen (or lumen) method, which links the illumination a surface needs to the total luminous flux the lamps must emit, after allowing for real-world losses.
Two correction factors reduce the useful light: the utilization factor (UF) accounts for flux that never reaches the working plane because it is absorbed by walls, ceiling and fitting geometry, while the maintenance factor (MF) allows for dirt on lamps and fittings and lamp ageing over time.
The working formula is \(\text{Total lumens}=\dfrac{E\times A}{UF\times MF}\), where E is the required lux and A is the area in square metres. Because UF and MF are both less than one, the lamps must always emit more flux than the bare lux-times-area figure.
Substituting E = 300 lux, A = 120 m2, UF = 0.7 and MF = 0.8 gives a numerator of \(300\times120=36000\) and a denominator of \(0.7\times0.8=0.56\).
Dividing, \(\dfrac{36000}{0.56}=64285.7\approx64286\) lumens.
The lower options come from wrong handling of the factors: 54000 lumens results from dividing by only 0.7 twice or ignoring one factor, while 37500 and 42800 come from multiplying rather than dividing by the factors, all of which understate the flux actually required.
Hence, the answer is 64286 lumens.
Similar Questions
While planning lighting for a machine assembly area, an engineer calculates the required number of luminaires. If the area is 60 square meters and the recommended illumination level is 300 lux, what is the total luminous flux required for the area?
A theater lighting designer must ensure that each part of the stage receives the same amount of illumination from overhead lights. If the distance between the lights and the stage is doubled, which action will maintain equal illumination across all areas, according to the laws of illumination?
A theater manager is selecting lamps for stage lighting, aiming to minimize both heat generation and maintenance costs. Considering lamp disadvantages, which type of lamp should NOT be used to achieve these goals?
Which of the following statements describes a difference between incandescent lamps and fluorescent lamps used in illumination?
Intensity of light is measured in:
Important Questions from Illumination
Silicon solar cell has an open circuit voltage NOT equivalent to-
What is the primary function of a choke in a tube light circuit?
Light is produced in electric discharge lamps by
________ lamps consist of an inner discharge tube and an outer evacuated tube.
A mercury vapor lamp gives ______ light.
