HunterLab ColorFlex EZ, User Manual

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ColorFlex EZ User’s Manual Version 2. 2
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CHAPTER SEVEN
Sample Preparation and Presentation
The ColorFlex EZ spectrophotometer is a versatile color measurement instrument that can be
used on products of virtually any size and in diverse industries. With its compact design, it can
be used to measure objects that would be difficult to position at the sample port of a larger
color instrument. However, careful attention to proper sample presentation and preparation is
required for consistent and accurate color measurements.
It is important to select samples appropriately, use an established measurement method, and
handle all samples in a consistent manner. The guidelines in this chapter will help while taking
measurements.
Selecting Samples
Choose samples that are representative of the material used. If samples are non-
representative of the batch or are spoiled, damaged, or irregular, then the result may be
biased. When choosing a sample, select randomly and examine the sample to avoid biased
results. If the sampling procedure is adequate, another sample selected from the same batch
should result in comparable measured values.
Preparing Samples
Prepare samples in the same manner each time they are measured. Follow standard industry
methods if they exist, such as ASTM or TAPPI methods.
Sample Presentation
Present the samples to the instrument in a standard, repeatable manner. Results obtained
depend on the condition of the samples and their presentation. If a method is established so
that the same procedure is used each time specific samples or types of samples are measured,
then there will be a valid basis for comparison of measured results. This also ensures
repeatability of results when measuring the same sample. Make a checklist so that operators
may simply check each step. The checklist will also help in the training of new operators.
There are variety of techniques that can be used in handling various forms of objects and
materials so that the most valid and repeatable measurement of their appearance results. For
example, when measuring the color of a sample, such as fabric, that is translucent, the sample
should be folded into multiple layers to make it appear more opaque. Other materials, such as
liquids or semi-solids, might be read through the glass of a sample cup, which presents a flat
surface to the instrument.
When taking readings, make sure that the sample surface is flat against the ColorFlex EZ sample
port. This may be difficult if the sample is curved or irregularly shaped. Look at the instrument
from all angles to make sure the port makes as much contact as possible with the product.
When measuring thin, soft materials (such as fabric or paper) place a hard, flat surface behind