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5.10 Calculation for a linear 1-point calibration curve
In practice during commissioning of a SONO probe in process, it could be happen that the measured material
above the probe is only available with a single moisture value. So a 2-point calibration could not be carried out.
The procedure described below is not as precisely like a 2-point calibration, but it could be a compromise to
achieve an acceptable result for a usable calibration curve.
Basic steps:
1. Measure the radar travel time Tp in the running process while the material lies or flows through the TRIME
GW Line measuring field. Tp can be measured with help of the module SM-USB or with the display module
SONO-VIEW.
2. Determine the reference moisture M in % of the measured material. Unless the material moisture is already
known, the reference moisture can be determined with an infrared- or microwave oven in the laboratory.
3. Determine the bulk density D of the material in kg per dm3. Unless the bulk density is already known this can
be done by weighing of exactly 1 liter volume of the material.
4. Download the Excel-Sheet „SONO 1-Point LinearCalibration_Calculation“ from IMKO´s Homepage /DOWN-
LOADS/SOFTWARE. Enter the three determined parameters Tp (Radar travel time), M (Moisture) und D (bulk
density) into the Excel-Sheet. As result you get the two calibration curve coefficients m0 and m1.
5. Enter, set and save both parameters m0 and m1 with help of the software „SONO-CONFIG“ in the menu
„Calibration“ in the window „Material Property Calibration“ in the selected calibration curve. The three
parameters Tp, M and D can be also entered without a PC with the module SONO-VIEW (see manual SONO-VIEW).
5.11 Calculation for a non-linear calibration curve
SONO probes can work also with non-linear calibration curves with polynomials up to 5th grade.
For a non-linear calibration it is necessary to calibrate with 4…8 different calibration points with different Tp values
and the related moisture values in %. To calculate nonlinear coefficients for polynomials up to 5th grade, an EXCEL
software tool from IMKO can be used.
1. Download the Excel-Sheet „SONO_NonlinearCalibration_Calculation“ from IMKO´s Homepage /DOWNLOADS/
SOFTWARE.
2. Enter the TP-values with the respective reference moisture values into the Excel-Sheet.
3. Read out the parameters m0 to m5 from the Excel-Sheet.
4. Enter, set and save the parameters m0 to m5 in the selected calibration curve with help of the software „SONO-
CONFIG“ in the menu „Calibration“ under the window „Material Property Calibration“.
5.12 Configuration of the Measuring Mode
TRIME-GW Line is pre-adjusted in the factory before delivery to mode CF. A process-related later new adjustment
of this device-internal setting is possible with the help of the service program SONO-CONFIG or directly online
with SONO-VIEW. For all activities regarding parameter setting and calibration the probe can be directly connected
via the RS485 interface to the PC via a RS485 USB-Module which is available from IMKO.
The following settings of TRIME-GW Line can be amended with the service program SONO-CONFI.
Measurement-Mode and Parameters:
•
Measurement Mode A-On-Request (only in network operation for the retrieval of measurement values via the
RS485 interface).
•
Measurement Mode C Cyclic:
•
TRIME-GW Line is supplied with suited parameters in Mode CF with 3 second average time for bulk goods.
