© PSI (Photon Systems Instruments), spol. s r. o.
16
Press OK and wait until the measurement is completed.
Measurements are automatically stored into the device memory and displayed on the screen.
Currently displayed graph represents
transmittance
data. Displayed graph would be switched to
absorbance data in Options menu (more information in chapter 8.3).
o
Transmittance:
the transmittance mode corresponds with reflectance in case of PolyPen
device. The measured spectral data are normalized to the white calibration standard by the
linear calculation:
T
=
I
/
I
0
, where
I
means the signal measured from the sample and
I
0
is the
ideal reflectance signal from the standard.
o
Absorbance:
The measured data are normalized to the white calibration standard as the
logarithmic ratio:
A
= log(
I
0
/
I
). This visualization mode does not have a special meaning in case
of PolyPen device, as this function is important for the trans-illumination geometry
measurement in PolyPen-Aqua.
INDICES TABLE
The table displays a group of selected indices calculated for actual measured data (Fig. 6). To define the
indices of interest, go to
Options > Settings > Indexes
. You can select
two indices
that are currently
displayed. However all indices are calculated and stored in the device memory. Entire list of the indices
can be displayed after a data download to PC. The software also allows a calculation of custom indices
defined by user (please refer to page 36).
Fig. 6 Indexes table
8.3
MAIN MENU
In this chapter the settings of the optimal device parameters and features of displayed data are described.
DEVICE
Calibrate – calibration can be run any time by pressing
Device > Calibrate
after inserting appropriate standard in
the leaf clip. (Fig. 7).
