holophane bowl type refractors
symmetrical type distribution
Holophane Standard Bowl Refractors are made of transparent glass with prismatic refracting surfaces, designed to
give extreme lateral light distribution with minimum absorption.
They are made in two pieces, one sealed within the other, with the prism surfaces enclsoed, and are therefore not liable to the
collection of dust and are easily cleaned.
They are made in three sizes to accommodate lamps from 60 to 750 watts, which comply with all ordinary conditions. A larger size
however, suitable for larger lamps is available, particulars of which will be supplied on application.
* From centre of filament to top of glass
Holophane Symmetrical Type Bowl Refractors give a symmertical light distribution all around the unit, the maximum candle
power being given in a zone from 70° to 80° from the vertical, and are intended for the illumination of relatively open areas.
This type should be isntalled where the street width exceeds 80 feet, and the spacing of the units is not materially greater than 8 times
the mounting height.
The light distribution is such that when the units have a spacing ration, distance apart to height, not greatly exceeding 8 to 1 reasonable
uniformity of street illumination will be obtained.
It is important that the lamp filament takes up the correct position relative to the refractor. These positions are given in detail on
Holophane Lanterns illustrated on Pages 28 to 30 are designed with a special focussing device to enable the lamp to be adjusted in position.
Recommended intensities for the various classes of thoroughfares will be found on page 4.
Table of Lumens required per lineal foot of street, with the Lumen rating of Gas Filled lamps will be found on
Pages 15 and 16.
"HOLOPHANE, SOWEST, London"
"VICTORIA, 2491, 8258."
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