Model L-202

Hagner Special Luminance Meter L-202

The Hagner Special Luminance Meter, model L-202, is a small, portable and simple but functional instrument, specially designed for measurement and evaluation of the luminance at road tunnel entrances and their surroundings. The measuring range is 0 - 200,000 cd/m². The L-202 is used to determine what measuring range is required for a stationary Tunnel Photo-
meter before it is ordered. With a measuring angle of 20º it measures, at a certain position from the tunnel entrance, the average luminance of the same area as a standard Tunnel Photometer would do at the same position. The displayed value can be locked by means of a hold button.
The built-in detector is carefully filtered to give a spectral response close to that of the human eye, as defined in CIE standards.
If required the L-202 can be mounted on a tripod by means of the standard camera thread (¼'') in the chassis.

Operation

When looking through the eye-piece, the outer circle of the viewing field represents the 20º measu-ring angle.
Move the slide switch to the range that gives the greatest degree of accuracy. If the instrument displays only a digit ?1?in the lefthand position, the input signal is too strong, and so a higher range
should be selected.
The hold button has two positions, hold and release.

Calibration

The instrument is carefully calibrated when delivered. As the light sensitive diode is extremely stable over long periods of time recalibration every two-three years should, under normal use of the instru-ment, be sufficient. If however there is any reason to believe that the instrument is out of calibration, it can be returned to your stockist or the manufacturer for earlier control checks.

Power source

The power source is a standard 9V battery. To avoid battery leakage only alkaline batteries should be used. When the battery charge is running low, the word ”BAT?will appear on the display. The instru-ment can then be used for another 10 hours (approx) before replacing the battery is essential.

Instrument Data

The spectral sensitivity of the Hagner luminance meter closely relates to the visibility curve of the CIE standard observer. Instrument data