IMKO TRIME-PICO 32, Руководство пользователя

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2017-05-30 Manual TRIME_PICO64-32 Version 2_0
Page 19
7 Material-Specific Calibration
Your TRIME measuring system operates with a universal calibration for mineral soils as a standard.
The following parameters limit the application range of the universal calibration:

Clay content: >50%

Organic content: >10%

Bulk density: <1.1kg/dm³ or >1.7kg/dm³
Exceeding these limits may cause the tolerances given on page 5 to be overstepped.
Material-specific calibration is advisable if your soil is listed above or if you require accuracy down to the last
digit. The
PICO-CONFIG software is required for setting up a material-specific calibration ( download under
www.imko.de ).
A test series with reference values is necessary for performing material-specific calibration (e .g. Oven drying at
105°C until weight is constant ). The test series –and consequently the calibration– should include minimum and
maximum moisture values. TRIME readings and reference values are compared in a table. The calibration coef-
ficients must then be calculated and uploaded to the TRIME-device.
7.1 Soil Density Correction with PICO Sensors
One of the most important advantages of PICO sensors is, that it is possible to measure volumetric
moisture for all soil types with <50% clay and <10% organic with just one calibration. The only factor is
the offset caused by the differing soil density, which can be compensated by a formula which IMKO
offers at its homepage in an Excel-File
“Soil Density Correction”.
Volcanic soils have normally lower densities, clayey soils can have higher densities.
It is possible to make an offset correction with Excel functions after datalogging of the stored moisture
values. But it is also possible to change the offset calibration parameter m0 inside the PICO probe
before installation and use of the PICO sensor. With help of the software tool PICO-CONFIG it is pos-
sible to load the
“Universal Soil”
calibration curve of the PICO sensor, to change it and store it back
to the sensor.
Necessary is to chan
ge the parameter m0 of the “Universal Soil” calibration curve inside the PICO
probe. If a soil has a lower density as 1,4 than the PICO senor measures a too low moisture value and
therefore the calibration parameter m0 has to be increased with an offset correction value.
E.g. if the soil density is 1,3 than the calibration parameter m0 has to be increased with +1,21.
If e.g. the calibration parameter m0 = -30 inside the PICO sensor than it has to be increased to
m0 = -30 + 1,21 =
-28,79
If the soil has a density higher than 1,4 than the calibration parameter m0 of the
“Universal Soil”
calibration curve has to be decreased with the appropriate offset correction value.