HunterLab EasyMatch QC, User Manual

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EasyMatch QC User’s Manual Version 2.1
UltraScan VIS 11G-55
Color Measurement Notes
This instrument can be used to measure virtually any kind of product. Opaque and translucent materials
can be placed at the reflectance port on the front of the sensor for measurement of reflected color.
Transparent samples such as films and liquids can be placed in the transmission compartment for
measurement of transmitted color.
When measuring samples, it is important to select samples appropriately, use an established
measurement method, and handle all samples in a consistent manner. The following guidelines will help
you while taking measurements.
Selecting, Preparing, and Presenting Samples
1. 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 your sampling procedure is
adequate, a different sample selected from the same batch should result in comparable measured
values.
2. Prepare samples in exactly the same manner each time they are measured. Follow standard methods
if they exist, such as ASTM or TAPPI methods.
3. Present the samples to the instrument in a standard, repeatable manner. Results measured depend on
the condition of the samples and their presentation. If you establish a method so that the same
procedure is used each time specific samples or types of samples are measured, then you will have 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.
More on Sample Presentation to the Instrument
There are a 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 cell, which presents a flat surface to the instrument.
Examples of ways to measure several types of samples are given below.
Directional Samples
Directionality can be minimized by averaging several measurements with rotation of the sample
between readings. Examination of the standard deviation displayed with the averaging function can
guide you in selecting the appropriate number of readings to average.
Non-opaque Samples
Non-opaque samples must have a consistent backing. A white uncalibrated tile or sample clamp is
recommended. If the sample is such that it can be folded to give multiple layers, such as tissue or lace,
the number of layers used for each measurement should be noted.