MODEL LSI-60 For Calibration of Luminance meter.
Produces a uniformly bright surface of 60 mm diameter.
Continuously adjustable from 0-approx. 1500 cd/m².
The LS1-60 luminance standard produces a uniformly bright surface with a diameter of 60 mm. The
luminance of the surface can be continuously varied from 0 to about 1500 cd/m². Irrespective of the
luminance value, the colour temperature remains constant at about 2850 K (Standard Illuminance
A). The luminance of the source is continuously measured and indicated on a built-in digital display.
The LS1-60 luminance standard is mains-powered, and should preferably be connected via a voltage
stabiliser. The light source is an incandescent lamp with an elliptical reflector. It has a life of about
2000 hours, and can easily be replaced. The condition of the lamp itself is not important, as the
luminance is measured and displayed by the instrument. A recorder output has been provided for
remote indication and recording.
Two versions of the LS1-60 are available:
1. The LS1-60-C, which is fitted with a clear glass window in the viewing aperture. This version of the
standard is intended for such applications as calibration of Hagner, Spectra and other tele-luminance
meters. On this model the displayed value agrees closely throughout the range with the actual
luminance of the viewing aperture. External light incident on the viewing opening does not affect
accuracy.
2. The LS1-60-D, which is fitted with an opal glass window. With this the luminance standard can be
used for calibration of luminance meters with wider acceptance angles then the telescopic versions,
e.g. for fibre optic detectors. The LS1-60-D also differs from the LS1-60-C in that the luminance
across the viewing aperture can vary somewhat (maximum 3%), and because the displayed value of
luminance does not agree exactly with the true luminance at all levels, although this effect applies
mainly at luminance levels below 50 cd/m². However, correction tables supplied with the LS1-60-D
make the instrument as easy to use as the LS1-60-C. Care should be taken to prevent ambient light
from reaching the viewing aperture when measuring very low luminance levels.
Part No
1) Hagner Model LSI-60-C Calibration of luminance meter
2) Hagner Model LSI-60-D Calibration of luminance meter
3) Hagner Model SA4 (for LSI-60) illuminance adaptor
