Used with EZ-ID sample identification software and the Custom Library Builder
module, you can collect known scans and create a library for comparison. The
ability to create site-specific library allows you to more accurately measure your
project area. Since EZ-ID saves all spectral data as an ASCII file, you can also work
with soil spectra available from international soil libraries.
Identifying and Analyzing Clays in Soil
 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
Most soils are a mixture of clay, organic matter, sand, and silt. Clays
play an important role in nutrient availability as they have a large
surface area and a negative charge. Plant nutrients tend to be
positively charged, such as CA++, Mg++, K+ and Na+. The ability to
hold and store positively charged ions is called cation exchange
capacity (CEC). The more clay in the soil mixture, the higher the CEC.

Clay also acts as a binder for soil particles, helping soil to hold
moisture and reduce nutrient loss due to leaching. Clays are silicate
minerals and include familiar clay minerals often found in soil like
kaolinite, illite, smectite, and montmorillonite.

Soil analysis using a
PSR+ full range UV/VIS/NIR spectroradiometer
with a 350-2500nm spectral range is fast, non-destructive, affordable,
and doesn’t involve hazardous chemicals. With our handheld sample
contact probe, soil spectra can be collected in the field from
outcrops or a soil pit. Analysis with
EZ-ID sample identification
software running on a tablet or laptop matches high resolution target
scans against two known sample libraries – the USGS and SpecMIN
libraries. A researcher is able to see the absorption features
characteristic of clays. For example, kaolinite has doublets at 1350-
1450nm and 2100-2250nm while smectite has pronounced absorption
near 1900nm due to water bound in the interlayer lattices as hydrated
cations. EZ-ID provides a best match based on examining the target
spectra and the library spectras. A researcher can add or remove
regions of interest to focus on only the prominent features in the
spectra for a better identification in clay mixtures.

The PSR+ field portable agricultural spectroradiometer from Spectral
Evolution has the features required for accurate and fast soil and
clay identification and analysis. With its industry leading resolution
and sensitivity, it collects clear spectra from clays and soil organic
matter that are essential for accurate analysis. The PSR+ is made for
field use—take it right into the soil pit and collect data from different
soil layers. Equipped with optional EZ-ID software, it can compare
your target spectra against two spectral libraries to match against
known samples of different clays from different locations. In addition,
the Custom Library Builder module allows you to create your own
spectral library from  known field samples for a particular application,
region, or analysis.

An all solid state photodiode array design eliminates failures in the
field. Field swappable fiber means a break does not require sending
the instrument back to the factory. The PSR+ weighs seven pounds
and fits in an optional backpack. Two re-chargeable Li-ion batteries
keep it powered for a full day of data collection.
 First in Full Range PDA Spectrometer, Spectroradiometer and Spectrophotometer Systems
The PSR+ is a field portable spectroradiometer for remote
sensing applications including identification of clays in soil.