Hagner - Model EC1-L -Digital Luminance Meter
The Hagner EC1-L Digital Luminance Meter is a small, handy and easy-to-use instrument for measuring luminance.
The opening of the detector, which should be pressed against the screens, has a round aperture with an area of 100mm2.
The meter is normally calibrated to read from 1 cd/m² to 2,000,000 cd/m² in four measurement ranges. This calibration is suitable for X-ray viewers. Other ranges, for instance from 0.1 - 200,000 cd/m² can be supplied on request.
The calculation of film density requires also a simple calculator which will give the logarithm to base 10 of a number (LOG10).
A. Measure the luminance (Ls) of the blank viewing screen and enter into the calculator.
B. Measure the luminance (Lf) of the film when placed over the screen.
Film density is then given by D = LOG10
Example
- Screen luminance is 1,352,000 cd/m2
- Film luminance is 107.2 cd/m2
If the value of screen luminance is stored in the memory of the calculator, the density at several different positions on the film can be calculated very easily.
- Detector: Silicon photodiode Vλ– filtered
- Measurement range: 0.1 - 199,900 cd/m² or 1 - 1,999,000 cd/m²
- Accuracy: Better then +/- 3% (+/- 1 in last digit)
- Power supply: 9 Volt battery type PP3 (lifetime 350 hours)
- Dimensions: 130 x 75 x 35
- Weight: 0.24 kg