The actual luminous fluxes of each filament lamp used shall not deviate more than  5 per cent from the mean value. Alternatively standard filament lamp(s) may be used in turn, in each of the individual positions, operated at its reference flux, the individual measurements in each position being added together.

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The actual luminous fluxes of each light source used shall not deviate more than  5 per cent from the mean value. Alternatively and in case of filament lamps only, a standard filament lamp may be used in turn, in each of the individual positions, operated at its reference flux, the individual measurements in each position being added together.

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