THE-RED-INFRAPHIL-LAMP
The oldest Infraphil heat lamps with model
number 7525 were made of matted
transparant glass. It's successors with
the model numbers 7526 and 7529 had a
red filter integrated in the glass and in the
documentation they were frequently
referred to as "the red Infraphil". Like all
Infraphil lamps, both white and red types
were equipped with an internal reflector.
The red filter did not influence the yield of
infrared radiation but it restrained the
bright visible light, preventing the need for
protective glasses.
The first part of the type number of early Infraphil heat lamps equaled that of the
model number of the armatures they were delivered with. The type number was
printed on the front of the lamp, together with the operation voltage and the wattage
(always 150W), a production code, the country of origin, the Philips trademark and an
Infraphil logo consisting of a rectangle with rounded corners with the brand name
infraphil in it. The point on the first letter i of infraphil was an eight-pointed star that
partly sticked out of the rectangle. The production code was formed from a
combination of small points and stripes in a fixed configuration.
