Measurement of small symbols and display segments

Recommended product: spectraval 1501 focus with focusing optics

The main application for light measurements in Luminance mode (directed measurement) are extended homogenious light sources as monitors or cinema projections. Sometimes the task is to measure small spots or structures, e.g. the symbols on illuminated control switches or alphanumeric displays.

The spectraval devices and specbos 1211 can measure spot sizes of 4 mm and more. But it is possible to equip them with a focusing optics creating a measuring spot of 3 mm, 1 mm diameter and 0.5 mm. The measuring distances are fixed.

Three focusing optics for measurements of 3 mm, 1 mm and 0.5 mm diameter are available. The measuring spot is still marked by a red circle. The 0.5 mm version is fitted out with a magnifying glass to simplify the precise adjustment (see the figure above).
All add-ons can easily be attached to the basic instrument by screwing. The version is automatically detected and the appropriate calibration data will be applied.

Examples for measuring objects

  • All kinds of displays with small light emitting structures
  • Fluorescence tubes with small diameter
  • Back illuminated signs
  • Other small light sources

Focusing optics

Focusing optics #1 #2 #3
Measuring diameter 3 mm 1 mm 0.5 mm
Measuring distance (from front face of the optics) 70 mm 26 mm 46 mm
Field of view 2.1° 1.9° 0.6°
Length of optics 77 mm 26 mm 77 mm

Remark: The focusing optics cannot be used with a standard spectraval or specbos1211-2, always the focus version must be used.

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