GROUP "B/AL"

The reflectors consist of one piece castings glazed with silvered glass facets, cut from flat sheet, embedded in a special atmospheric resisting cement. Each facet is set at the exact angle and is of a calculated size to produce the desired light distribution.

Material: Cast iron or Aluminium non-corrosive alloy.
Finish: Green or Aluminium. Other colours to order.
Tapping: 1" gas thread as standard. Tappings to 1¼" to order.
Lamp Holders: Rigid Goliath Edison Screw.

approximate dimensions and weights

The reflectors are designed to produce a light distribution of the required characteristics to ensure good uniformity of illumination and road brightness. The peak candle power is projected at an angle of 12½^o below the horizontal.

A special patented method of light control is employed, by which the elongated light source is split into two imaginary sections, each reflector redirecting the light flux from the respective sections.

The optical design is such that the light from the discharge lamp is applied to the road with the maximum of utility, latitude, and precision. This reflector can be applied to all unusual road conditions (bends, intersections, etc.) with the same ease and efficiency as for a straight normal road.

These reflectors greatly enhance the advantages of this new light source in a very practical and economical matter. The efficiency is the highest available and the maintenance costs (particularly cleaning) are extremely low.

(Data relating to "Philora" mercury lamps is given on back page).

mounting height

We definitely recommend that the mounting height should not be less than 25 feet. In the case of the 250 watt lamp the height might, with care, be reduced to 22-23 feet, but in this case the reflector should be glaed with a special grade semi-diffusing glass in order to reduce the brightness of the reflectors.

angular settings

These reflectors are available in all the various angles as scheduled on the Catalogue section dealing with the Group "B" filament lamp reflector.

In addition, a very interesting modification may be adopted in the case of three way and four way road intersections by which the light flux may be directed on to the various roads in direct proportion to their traffic density and importance. This flexibility is effected by combining a three way upper reflector with a two way lower, or a four way upper with a three or two way lower.

For example, taking a simple case of a central suspension unit at a "T" intersection of exact right angles; the branch road being of less importance than the straight through road; a 180^o/90^o/90^o three way upper reflector might be combined with a 180^o two way lower reflector. Thus there would be two pairs of reflector wings operating up and down the main road but only one reflector wing projecting down the branch road. This is a very useful procedure where it is not desited to unduly sacrifice the light on the main road for the sake of the side road.

Where economy is a serious consideration the lower reflector can be omitted and added at a later date. The results will be quite good, but of course will not equal those of the double reflector.

In the case of certain 250 watt lamps of short column length, we have found it advisable to use only the upper reflector. (The designation of the single reflector is Group "B/M").

technical service

The personal services of our technical staff at the works are at our clients' disposal at all times. They are prepared to visit a district in order to advise on all street lighting problems, also to inspect every individual lighting position to ascertain the correct reflector, or this latter work can be done reasonably well from plans.

They are also ready to carry out photometric tests on site, for which purpose they are equipped with the latest portable photometers available.

schedule of angles