LaMotte SMART 3 Electronic Soil Lab - Manual (Page 24)

24 SMART3 Soil 1.11
CALIBRATING LaMOTTE PRE-PROGRAMMED TESTS 
The LaMotte Pre-Programmed Tests have been pre-calibrated. Recalibration of
the pre-programmed tests by the user is not possible. However, a procedure
to standardize the calibration can be performed to obtain the most accurate
readings or to meet regulatory requirements.
The LaMotte Pre-Programmed tests are standardized with one standard
solution. To standardize over the full range of the test, the concentration of
the standard should be chosen from the high end of the range. Alternatively, if
samples do not cover the full range of the test, a standard should be chosen
that is close to the concentration of the samples.
For the SMART3 Soil colorimeter, the standard should be prepared in distilled
or deionized water for the range of the reagent system before the multiplication
factor has been applied to the reading on the display. The following standards
are recommended to standardize over the full range of the tests:
Ammonia Nitrogen 3.00 ppm Ammonia Nitrogen
Copper
4.00 ppm Copper
Iron 4.00 ppm Iron
Manganese 11.00 ppm Manganese
Nitrate Nitrogen 2.00 ppm Nitrate Nitrogen
Nitrite Nitrogen 0.60 ppm Nitrite Nitrogen
Phosphorus 2.00 ppm Phosphate
Potassium 7.00 ppm Potassium
Sulfur 75 ppm Sulfate
Zinc 2.00 ppm Zinc
The standardization procedure should be followed as often as required by
regulations and laws for compliance monitoring.
In the example below, the Aluminum calibration will be standardized.
Prepare a standard solution to be tested. In this example, 0.30 ppm aluminum.
Testing