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Typical Questions about Color-Tec LED Instruments
- What is the difference between LED instruments and traditional color
instruments?
Traditional color instruments are supplied with
tungsten or xenon white light sources. They are filtered or corrected
light bulbs that are burning out as you use the instrument and are
temperature sensitive, therefore they require constant recalibration
every day as you use them. LED's become more stable as you use them and
are data corrected for temperature changes. They are rugged, low cost
and highly dependable, yet offer all of the precision and colorimetric
output of traditional color instruments.
What is the best aperture to measure my samples? We offer 3mm,
12mm and 26mm portable instrument aperture options. We most commonly sell the 12mm aperture instrument for standard
applications, the 3mm for small targets and the 26mm for non-uniform or
large surfaces.
How complicated is the training? Most of the accounts we sell find
our LED instruments and software intuitive to operate. We do 90% of our
support by phone, over the web and with email.
What does the portable display/Screen look like. The screen is a
standard LED display of 2 lines of 16 characters.
Can we attach a printer or store the reading to download it? The
instrument holds up to 500 measurements and comes with a RS232 interface.
You can upload standards from our ColorSoft-QCW software and download the
data stored on the instrument. If associated with a color standard, the
data downloaded can be associated with the standard. You can print all
results from the PC.
Can we store color standards in memory to recall it later? You can
store one or multiple standards in the instrument flash (Advanced QC)
memory and select them on the instrument by name or by number. We also
have an "Auto Select" feature that allows automatic colorimetric
selection. This works well when your standards are significantly apart in
color space.
How easy to calibrate? You can calibrate either on the instrument
in portable mode or via the software when driven by a PC using ColorSoftÒ
. The user is guided to measure a black and white calibration standard
supplied with the instrument. In the software we also supply a full
diagnostic package.
Do you offer ISO traceable calibration standards? In color it is
the white calibration standard that must be traceable and can be
certified. We supply traceable internationally accepted Vinyl transfer
standards with the instrument and offer as an option Certified Ceramic
Calibration Standards.
Does it read color under various lighting conditions? Our LED
color instruments measure the absolute spectrophotometric response
relative to each type of LED illumination. The data is converted to the
RGB response and then weighted by internationally published CIE illuminant
data. On the instrument we supply daylight (D65), F10 cool white
Fluorescent, A Tungsten illuminant math. The on board logic calculates the
X,Y,Z for each of the illuminant weightings which is then converted to
color difference output (Hunter L,a,b or CIELAB or LCh or CMC) which is
calculated both on the instrument or in the PC software. In ColorSoftÒ
we offer many additional illuminant weightings.
What angle of observation does it read? The 3mm and 12mm
instruments LED light sources illuminate 45 degrees circumferential to the
sample, the reflected light is at the 0 angle, this is referred to as 45/0
geometry. The 20mm the LED light sources are arranged so that the light
returning from the sample is diffuse to the sensor.
What is the repeatability of LED color instruments? The
repeatability specification is expressed as delta E (the square root of
the sum of the squares of the color difference). A delta E of 1.0 is
defined as a "just noticeable color difference as judged by a panel
of normal Observers." Our specification for short-term repeatability
is 0.13 standard deviation CIELAB as measured 30 times on a standard white
ceramic. This means that the instrument is an order of magnitude more
precise than a human eye is.
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