ALTANA LCM IV - Manual (Page 57)

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Standard programs
The current result of the actual reading and all further
measurements will be displayed in the selected color scale.
Alternative
1. Tap the touch-sensitive area Result .
2. The result is shown in the next color scale in the list.
5.5.1.4 Change the measuring range after a measurement
1. Tap the touch-sensitive areas for the upper or lower limits of
the barchart.
2. Enter the new limit and press OK to confirm.
Note: The changed measurement range limit is displayed in blue.
Note: It is only possible to change the limits inside the measuring range
of the color scale. It is not possible to expand the range, e. g. to Hazen
2000.
The current result and all further measurements will be displayed
with the new measuring range.
5.5.2 Determination of the iodine color value
DIN 6162 defines the iodine color value as mg iodine per 100 mL
potassium iodide solution. Color matching with the iodine color
scale determines the depth of color of clear liquids like solvents,
plasticisers, resins, oils and fatty acids, whose color is similar to
that of a solution of iodine and potassium iodide of the same
thickness.
For iodine color values of less than or approximately 1, the
determination of the Hazen value according to DIN-ISO 6271 is to
be preferred. Taking and preparing samples is described in
Chapter 5.4, Page 53 . The iodine color value can be determined
with sufficient accuracy using an 11 mm disposable glass round
cuvette.
5.5.3 Determination of the Hazen color value (Pt-Co or APHA method)
The Hazen color value (ISO 6271, also referred to as the "APHA
method" or Platinum-Cobalt Scale) is defined as mg platinum per
1 liter of solution. The Hazen parent solution comprises 1.246 g
potassium-hexachloroplatinate (IV) and 1.00 g cobalt(II) chloride,
which is dissolved in 100 mL hydrochloric acid and topped up to
1000 mL with distilled water.
The Hazen-color scale is used to evaluate the colors of nearly
water-clear products. It has narrower gradations in the light
yellow range than the Iodine Color Scale and extends to
water-clear color casts.
Note: Samples with Hazen values of between 50 and 1000 can be
measured with sufficient accuracy in 10 mm square and 11 mm round