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In
theory
How
is Color created ?
Without
light there would no color.
In
1666, Newton conducted an experiment by shining light through
a glass prism. He observed that light separated into a multi-colored
band that showed the same color distribution in a rainbow.
This demonstrated that white light is composed of a great number
of colored rays.
Visual
perception is a result of the brain's interpretation of the light
perceived by the eyes, which is altered and emitted by objects.
Objects are perceived depending on the way in which they alter
the light that illuminates them. The result of this distribution
of light is us our visual impression of the object.
Colors
are "created" in our brain through the analysis of light
given off by a color sample, using three types of sensors (called
red, green and blue cones). Indeed, when matter is
illuminated by incident light, it reflects a small portion of
this light directly without altering its spectral composition.
This constitutes their specular gloss.
Most of the light penetrates the color layer and is partially
absorbed or diffused selectively based on the wavelengths. The
light that is absorbed transforms into heat, the rest of the light
exits the color layer by diffusion, and it is this diffused energy
that gives us our perception of color.
How
is Color measured ?
The
spectrocolorimeter is an instrument that uses the above principles
to measure color. Indeed, the sample to be measured is illuminated
by incident light. The color sample absorbs a certain amount
of this incident energy and reflects the rest. Using an
optical device called a monochromator similar to the prism used
by Newton, the spectrocolorimeter breaks down the diffused
energy given off by the sample the entire length of the visible
spectrum and quantifies it. In doing so, the spectrocolorimeter
is able to draw a curve based on the length of the wave which
represents the energy diffused by the object. The selective
absorption of certain wavelengths determines our perception of
color.
The
spectral curve, indicating the ratio between the incident
energy and the energy diffused by the sample, is the the color's
distinguishing feature.
In
practice
How
do you choose a measuring instrument ?
Because
color plays a major role in the quality of your products, you
would like to implement color testing within your company.
You must determine beforehand at what point you wish to conduct
your color test.
This
can
be performed in the laboratory, at any point in the products'
production, on finished products, or at the point of reception
of the raw materials.
Identifying
your goals, the nature of the samples to be measured, and those
who will be using the instrument will make it easier to choose
an instrument and its accessories.
In addition, as you are preparing to implement the color test,
it is essential that you first take into account all parameters
of the sample.
Its shape, the appearance of its surface, its size and
how it responds to light (whether it is fluorescent, shiny, metallic,
etc.) will determine if the color sample to be measured will need
a particular type of measuring device that may require certain
accessories.
How do you perform a Color
measurement ?
The
"perfect" object to measure is flat, opaque and uniform
in color, spectrum and diffusion.
Unfortunately, few if any any samples display these properties.
Thus the implementation of a sample, meaning its preparation and
presentation for measure, will give measurement results that tell
you what you want to know.
However, this implementation must also be reproducible and any
operator should be able produce the same results from a given
sample.
Choosing the right accessories and procedures for preparation
and presentation of the sample will facilitate the task of implementing
the colored sample.
The
3C Offer
3C
has a wide range of measuring instruments and can help you to
choose those that best meet your measurement and operational needs.
3C
takes service to the next level, offering you consulting on sample
implementation, in order to offer you the ideal methods
and accessories to help you obtain measurements that are reproducible
and deliver the results you seek.
The 3C experts will help you make the best choices
by conducting a detailed audit of your industrial sampling techniques
and your color data operating needs.
An
expert opinion
Measuring
instruments are top-notch these days.
Matching an instrument to your current and future needs as well
as the ease of implementation will drive the decisions you make
in choosing a particular model and its options.
For
more information
Supporting
documents available in the Color Shop:
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Instrumental
control
