Dickey-John Instalab 700 NIR, Operator'S Manual

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OPERATOR’S MANUAL
Instalab 700 NIR Product Analyzer
11001-1574-201107
14 CALIBRATIONS
Selection of a training sample set for calibration may frequently be aided by
using a “rough” calibration, such as a calibration for a similar product to
segregate samples and to ensure a set of samples across the desired
range of interest are collected. This technique reduces the number of
samples to be analyzed by the more cumbersome reference methods.
PRODUCT CHARACTERISTICS
Variations in product characteristics such as color, hardness, and the
amount of hull or foreign material may necessitate separate calibration
constants for determinations.
Color and hardness can affect the amount of light that is absorbed by the
product and the amount that is reflected. The amount of hull and foreign
material can affect the particle distribution causing different sized particles
to be unevenly distributed throughout the sample.
Also NIR is sensitive to particle size and particle size variations. All samples
in the training set and in future analysis should have a similar grinding
process.
SAMPLE MOISTURE CONTENT
The moisture content of a sample is important since the concentration of the
remaining constituents (expressed as a percentage of the total weight) is a
function of the moisture content.
Example:
A product with the following analysis:
Moisture 7.0%
Oil 8.0%
Protein 72.0%
If this same sample is dried to 3% moisture, the analysis becomes:
Moisture 3.0%
Oil 8.34%
Protein 75.1%
If this change in moisture occurs between the time the laboratory reference
analysis and Instalab analysis is performed, a 3.1% difference in protein
determinations could result.
IMPORTANT: If an As-Is calibration is developed, the moisture of the
sample should be recorded at the time of collecting logs
on the Instalab. Also moisture should be measured at
the time of the As-Is lab analysis. This allows
constituent values to be adjusted to a common moisture
basis should the moisture change between log
collection and lab analysis.