USTER HVI 900 - Color;Trash Modules

USTER® HVI 900 Instruction Manual
Uster Technologies, Inc. Chapter 1
Version 4.0 (1.99) Introduction - Page 1-5
5.6 Color/Trash Modules
The Color/Trash instrument for measuring cotton color (reflectiveness
and yellowness) and trash is located in the smaller cabinet that also
houses the Micronaire Module. The color/trash tray is mounted on the
tabletop. A pneumatic-powered automatic pressure plate that applies a
consistent amount of pressure during testing is located directly above the
tray.
Color and trash are measured by placing a sample on top of the tray
and by pressing the start button(s) (mounted flush with the tabletop on
either one or both sides of the color/trash tray). This will cause the
pressure plate to descend to the test tray.
The HVI 900 system uses two lamps to measure a sample during testing.
The two color components of cotton—reflectiveness and yellowness—
are measured when the light reflected passes through the filters and is
deflected by photo diodes. This reflectiveness is expressed as a percent
reflectance (%Rd).
The yellowness is expressed in Hunter's scale (+b) values. These values
are converted into the equivalent USDA color grade codes that are
based on the universal standards for grading American Upland and/or
Pima cottons.
The Trash Module is an automated video image processor that measures
the amount of visible leaf or trash in a sample of cotton. The digitized
image produces results for three measurements:
♦ Trash area—the percent of the sample viewing area
occupied by trash.
♦ Trash count—an indication of the number of trash
particles •0.01 inch in diameter or larger.
♦ Trash code or leaf—a code value related to the trash
area (10 * trash area, example: area = 0.37%, leaf = 04).