the General-X-Ray Infrared Lamp for Home Treatment was intended for medical applications
General-X-Ray heat lamp
As long as the current density (the current per
square millimeter) of an heating element was
relatively low, the wavelength of the photons emitted
by the element would be in the mid- and long wave
infrared area and no glowing would be visible. Such
so-called dull radiators emitted relatively little energy
per surface area but by using large elements a
substantial amount of energy could still be
dissipated. Larger long wave infrared radiators were
most often used for environmental heating purposes
and since warmth in general contributes to human
well-being there was, apart from the size, little
difference with dull radiators for medical purposes
like the General-X-Ray Infrared Lamp for Home
Treatment on display here.