The IL1 is a general-purpose light source for use in the UV, visible and infra-red spectral regions from 350nm to 2.5mm.
A quartz halogen lamp controlled by a current stabilised power supply is employed.A single quartz condenser lens is used to fill the height and width of the slit and to match to the F/4 optics of the monochromator. The quartz halogen lamp is unsurpassed for stability by any other source and should always be used where it provides sufficient output in the wavelength region of interest.

Stability of light output	Better than 0.1% over 8-hour period (when used with 605 p.s.u.)
Peak irradiance:	1.3mW cm-2 nm-1 at 880nm
Lamp:	100W quartz halogen
Horizontal adjustment	by screw slide
Vertical adjustment	by slackening nuts in T-slots
Lens	Single quartz condenser lens, adjustable focus
Power leads	1m long with spade terminals provided

Bracket for mounting 218 optical chopper is included