mailing list
site map

holophane bowl type refractors
2-way axial (180°)

Holophane Two-Way Bowl Refractors are similar in size and mechanical construction to the standard symmetrical types, but the prism formation is designed to concentrate the light rays in two main directions instead of symmetrically around the unit.

This Two-Way concentration gives higher intensities than those obtained with the standard type and therefore permits of wider spacing with equivalent uniformity of illumination.

This type distributes the two main beams at an angle 180 degrees horizontally. The maximum candle power being given from 70 to 80 degrees from the vertical in two directions, therefore it should be used when the units are installed in the centre of the road and between street intersections.


List No. Gas Filled Type Lamps
Overall Dimensions ins. Standard Position
of Lamp*
Diam. Height.
22/4437 60-100 6 60mm.
22/4438 150-300 80mm.
22/4433 500-750 11¾ 9 92mm.

* From centre of filament to top of glass

Vertical Candle Power Distribution Curve.
Lobes 160° Apart Horizontally.

Plan Candle Power Distribution Curve.
Through a 80° Cone.

Holophane 2-Way Refractors should be installed where the width of the street does not exceed 80 feet and the spacing ratio, distance apart to height, is from 8-1 to 12-1.

It is important that the lamp filament takes up the correct position relative to the refractor. These positions are given in detail on Page 13.

Holophane Lanterns illustrated on Pages 28 to 30 are designed with a special focussing device to enable the lamp to be adjusted in position and also with special projections in the band so that the refractor must be fitted in the correct relation to the lantern for proper orientation with reference to the street.

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 Ltd
Elverton Street,
Vincent Square
London, S.W.1
Telegrams :-
Telephones :-
"VICTORIA, 2491, 8258."

Back To Contents