Note
On a Nicolet 6700, the setting of the Aperture parameter determines
the
area
of the aperture opening. Doubling the setting approximately
doubles the area. The light energy is proportional to the aperture
area. A setting of 100 gives a nominal aperture diameter of 8 mm
and an approximate area of 0.50 cm
2
.
S
The following table lists recommended aperture settings for different
detectors with the appropriate energy screen installed. (See the
preceding section for information about the correct energy screen to
use for each detector type.) The settings in the table are based on the
physical size of the detector elements and maximize the amount of
infrared energy that reaches the sample. To correct linearity and
photometric accuracy problems, you can reduce the setting, but you
will pay a price in terms of the signal-to-noise ratio.
Detector Aperture
Setting
DTGS 100
MCT-A, MCT-B, InSb, PbSe, Si, InGaAs
32
?
In OMNIC Help Topics find “aperture” in the Index and go to
“Setting the aperture size” for information about changing the
aperture setting.
68 Thermo Electron Corporation
