Dickey-John Instalab 700 NIR, Руководство оператора, Страница: 106 / 111

OPERATOR’S MANUAL
Instalab 700 NIR Product Analyzer
11001-1574-201107
102 APPENDIX C
Unlike the “Standard” gain selection, the “Enhanced” gain selection uses a
sample raw log value that is adjusted for X2 gain (not unity gain). No matter
whether a X2 gain is used or a X4 gain, the raw log value is normalized to
X2 gain.
A special case may exist on the “Enhanced” gain selection when a stored
reference gain for a filter may be X4. This typically does not happen on
standard wavelength optical filters; however, a special filter can be used
that has lower transmittance and a X4 gain can be selected as the
reference measurement.
In the “Enhanced” gain selection, this condition calls for a X8 gain on the
sample. A X8 gain is not available. In this unique case, a X4 gain is used
and the raw log value is still normalized to X2. This gives a raw log value
theoretically equal to that of a X8 gain; but does suffer some in lower
resolution due to a lower signal level in the analog-to-digital converter.
Normalizing to X2 gain corrects the overall gain shift from X8 to X4.