Checking of Lux level values and giving recommandations for maintaning lux level as per guidlines:
he quantity of light reaching a certain surface is usually the main consideration in designing a lighting system.
This quantity of light is specified by illuminance measured in lux, and as this level varies across the working plane, an average figure is used.
Lighting Guides give values of illuminance that are suitable for various areas.
The section - Lighting Levels in these notes also gives illuminance values.
The lumen method is used to determine the number of lamps that should be installed for a given area or room.
Calculating for the Lumen Method
The method is a commonly used technique of lighting design, which is valid, if the light fittings (luminaires) are to be mounted overhead in a regular pattern.
The luminous flux output (lumens) of each lamp needs to be known as well as details of the luminaires and the room surfaces.
Usually the illuminance is already specified e.g. office 500 lux, kitchen 300 lux, the designer chooses suitable luminaires and then wishes to know how many are required.