HunterLab SpectraTrend HT, Руководство пользователя

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SpectraTrend HT User’s Guide 3.2
9
System Components
The following sections provide a brief description of the SpectraTrend HT basic system
components. Numbered images of each system component are located at the end of Chapter 1.
Please refer to Chapter 2 for installation instructions.
System Components
The SpectraTrend HT sensor (Figure 1-6) head is housed in a National Electrical Manufacturers
Association (NEMA) 4/Ingress Protection Rating (IP) 66 enclosure and is designed to be
mounted above the product. The sensor monitors the product and sends color and height
information to the fixed terminal, EasyMatch OL ST software, or other external device. The
sensor does not need to make direct contact with the product. The sensor window should be
located at least 2.5 inches (63.5 mm) and not more than 4.5 inches (114.3 mm) from the
product.
How the Sensor Works
The color-monitoring process is controlled by a microprocessor. Measurements are
taken at a frequency of approximately 5 Hz using a solid-state, LED illumination and
detection system.
The light illuminating the product is produced by 4 LEDs: 2-white, 1-cyan (499nm), and
1- UV (402nm). The LEDs produce light in the visible region of the electromagnetic
spectrum. The light is directed toward the product, and a relay lens gathers the
reflected light and transmits it to the spectrophotometer. Each light source is switched
on with modulation at a preset frequency. In addition to the LED light source(s), there is
a receiving lens and a detector in the sensor.
The receiving lens collects light diffusely reflected from the product and focuses it onto
a position-sensitive spectrophotometer. The information from the detector is then used
for calculation of colorimetric data. A separate Laser detector also provides signals from
which the distance from the sensor window to the top of the product being measured is
computed via optical triangulation. This information is converted so that the height of
the product itself is displayed. The distance is also used to calculate a mathematical
compensation for the way in which the reflected color signal changes when the product
position varies.
NOTE: The minimum reflectance that the laser detector on this instrument can
detect is about 15%. Therefore, it is not recommended for height compensated
measurement of black or near-black samples.
The Slide-On Manual Calibrator
The slide-on calibrator allows easy installation and removal of the standard tiles. It slides
onto the track under the sensor window to allow consistent and accurate placement of
the standard tile during standardization.