They Provide Support and electrical connection to the lamp. They are used to control and direct the light and distribute as required. They help to keep the operating temperature within prescribed limits. Using Rousseau diagram, graphical techniques are employed to obtain the MSLI. They should be easy to install and maintain and have a pleasing appearance. They are expected to b economically viable. Thus Requirements for good luminaries may be listed as
i. to provide support & electrical connection to the lamp
ii. to control, direct & distribute light as required
iii. to keep operating temp. within prescribed limits
iv. should be easy to install & maintain
v. should have aesthetically pleasing appearance and
vi. be economically viable
In them Lens & prisms can be used for focusing the light one has to keep in mind Depreciation which is often used as Maintenance factor varies from 0.85 – 0.6. This lesson had a look at the ways of measuring light output of a Lamp. They consisted using photometric bench, either by comparison or reading on an illumination meter. Luminaries which form integral part of Illumination system are characterized by polar luminance curves. Way to assess their luminance has also been discussed.