The tubes that are included with the colorimeter have an index mark to
facilitate this.
SELECTING AN APPROPRIATE WAVELENGTH
The most appropriate wavelength to use when creating a calibration
curve is usually the one which gives the greatest change in absorbance
from the lowest reacted standard concentration to the highest reacted
standard concentration. However, the absorbance of the highest reacted
standard concentration should never be greater than 1.5 to 2.0
absorbance units. Scan the lowest and highest reacted standards at
different wavelengths using the %T/ABS Sequence to find the
wavelength which gives the greatest change in absorbance without
exceeding 1.5 to 2.0 absorbance units. Use this wavelength to create a
calibration curve. Below is a list of suggested wavelength for the color of
the reacted samples
Color
Wavelength
Yellow
420
Yellow-Orange
460
Orange
510
Pink
530
Red
570
Green and Blue
605
CALIBRATION CURVES
The SMART Colorimeter contains 42 precalibrated tests for the LaMotte
reagent systems (see Page 49). The first step in using a non-LaMotte
reagent system with your SMART Colorimeter is to create a calibration
curve for the reagent system. To create a calibration curve, prepare
standard solutions of the test factor and use the reagent system to test the
standard solutions with the SMART Colorimeter.
Plot the results (in Absorbance or %Transmittance) versus concentration
to create a calibration curve. The calibration curve may then be used to
identify the concentration of an unknown sample by testing the
unknown, reading Absorbance or %T, and finding the corresponding
concentration from the curve. The linear range of the reagent system can
be determined and this information can be used to input a User Test into
the SMART Colorimeter (see EDIT USER TESTS Page 34).
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SMART COLORIMETER
