Every Spectral Evolution instrument includes DARWin SP Data Acquisition software with 19 built-in vegetation indices, including PRI
and the Red/Green index.
Measuring Efficient Light Usage in Plants
 First in Full Range PDA Spectrometer, Spectroradiometer and Spectrophotometer Systems
1 Canal Street  ◊  Unit B1
Lawrence, MA 01840  USA
Tel: 978 687-1833  ◊  Fax: 978 945-0372

Copyright © 2012 Spectral Evolution, Inc
The leaf clip includes a built-in white reference and is designed to keep the heat from the illumination away
from your sample so that measurements can be accurate and non-destructive.
With a PSR+  spectroradiometer a researcher can measure leaf
reflectance and use the Photochemical Reflectance Index (PRI) to
capture an accurate indication of a plant's ability to absorb and use
energy efficiently. One of the 19 vegetation indices offered with
DARWin SP Data Acquisition software and the PSR+ field
spectroradiometer, PRI looks at the carotenoid pigments, especially
the xanthophyll pigments absorbed by plants. The pigments can
signify growth rate and biomass production. PRI uses the
wavelengths of light from 400 to 700 nanometers and has a
measurement range of -1 to 1 with healthy vegetation falling between
the values of -0.2 to 0.2 in the PRI index.

In addition to PRI, the PSR+ with DARWin SP includes the Red/Green
Index for  growth cycle studies, stress detection of canopies, and
prediction of potential crop yield. The Red/Green Index measures the
expression of leaf redness caused by anthocyanin to the green
caused by chlorophyll. It can be used as an indication of leaf
production and/or stress. The means of the bands in the red range
are divided by those in the green range. The typical range for green
vegetation is 0.7 to 3.

The PSR+ is a high resolution, field portable spectroradiometer
ideally suited for vegetation, canopy and crop studies. With its solid
state design and three photodiode arrays, it provides a rugged and
reliable way to measure plants
in situ. Auto-shutter, auto-exposure
and auto-dark correction deliver fast one-touch operation. Use with a
range of direct attach lenses or fiber optic connection with FOV
lenses or leaf clip, contact probe or pistol grip.
 First in Full Range PDA Spectrometer, Spectroradiometer and Spectrophotometer Systems
PSR+ with the unique leaf clip for vegetation research in the field.