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RetroSign GR1 & GR3 · Retroreflectometer
Reference cap
To make sure that the calibration of the Retroreflectometer is correct it is important that the surface on the reference cap
is clean and undamaged. Keep the cap protected, and be careful not to touch the reference cap (reflective side).
If the surface is stained, scratched, or broken the reference cap must be replaced.
In case of dust on the surface, clean the reference cap gently by using a soft cloth with a mild household detergent. Wipe
carefully with dry linen cloth afterwards.
To ensure reliable measurements, it is recommended that the reference cap is periodically recalibrated to a traceable
standard. DELTA Light & Optics offers calibration traceable to PTB (Physikalisch-Technishe Bundesanstalt) and NIST
(National Institute of Standards and Technology). For information contact your local distributor or DELTA Light & Optics,
Denmark.
Calibration
The RetroSign is factory calibrated, but a calibration should always be carried out before starting a series of measure-
ments.
The calibration process automatically compensates for instrument offsets, leakage and other known “errors” and calcu-
lates calibration factors for each observation angle.
After a calibration the Retroreflectometer will display »true«
R
A
values.
Store the reference cap in a dry and clean environment.
Reference cap.
