Jadak Photo Research SpectraScan PR-7 Series, User Manual

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Chapter 8
– How to Make a Luminance / Radiance Measurement
91
U
SING THE
FP-730
FIGURE 77 - FP-655 / FP-670
The FP-730 Flexible Probe enables the PR-7XX to measure surface luminance and radiance of backlit sources
(e.g. cathode ray tubes, fluorescent lamps and self-luminous displays) that can be placed in contact with the tip
of the Probe.
The Flexible Probe is particularly useful for measuring in nearly inaccessible locations. The probe consists of a
24-inch (0.6 meter), flexible fiber bundle and a threaded mounting adaptor. 4 foot and 10 foot versions are
available
– contact Photo Research for details.
It can also be used to approximate the luminance of more distant sources, averaged over a circular field. The
acceptance angle of the probe is approximately 30

at the half-power points and 50° at the 10% response points.
The measuring area is 0.125 inch (3 mm) in diameter when the tip of the probe is placed in contact with a
Lambertian source.
Warning: The FP-730 is not recommended for use when measuring LCDs as the act of
coming in contact with the device may distort the surface and yield erroneous
readings and may cause damage to the display.
1. Remove the MS-75 Objective lens or other primary accessory by turning it counterclockwise.
2. Install the FP-730 by screwing in clockwise. Do not over-tighten!
3. From the Instrument Setup
menu, touch the ▲ ▼ icons adjacent to
Primary Accessory until
FP-730 appears. Note that only the largest aperture can be used for this accessory. The instrument will
automatically set the Aperture selection to the largest system configured aperture.
4. Make any other changes such as Sensitivity, Speed, Average etc.
5. Place the front surface of the probe tip in contact with the target. Make sure it is within the lit area of the
device under test.
6. Touch the MEASURE button to begin a measurement.