Appendix B Reference Information; Frequently Asked Questions (Faq); How Often Do I Need To Optimize; How Often Do I Need A White Reference (Wr) - ASD FieldSpec 3 User Manual

Appendix B Reference Information

B.1

Frequently Asked Questions (FAQ)

B.1.1

How often do I need to optimize?

B.1.2

How often do I need a White Reference (WR)?

Inside Use
Outside Use
© 2005 Analytical Spectral Devices, Inc.
Optimization has no affect on the data unless the measurement has drifted
towards saturation, in which case optimization is mandatory.
To be safe, optimize every 10 to 15 minutes.
When using the instrument inside under constant lighting conditions, collect a
white reference every 10 to 15 minutes while the instrument is warming up
and then every 30 minutes thereafter.
When using the instrument outside, you should collect a new white reference
frequently for:
• solar changes, like the sun's angle in the sky where 10 minutes can
represent a change in the measurement;
• atmospheric changes, like blue sky, cloud cover, humidity, or water vapor
• temperature changes
It is important that the light intensity is the same for when the white reference
is collected as for the measurements of the sample.
An experiment to perform when outside is to continue to take measurements
of the white reference panel and observe the stability of the white reference
line. This will give you an idea of how the current fluctuations in weather
affect your measurements.
75 FieldSpec® 3 User Manual