Method for calibrating a measuring apparatus

A computer-implemented method for calibrating a microwave measuring apparatus for a plurality of products, the method being executed by a processor operatively connected to the microwave measuring apparatus, comprising:

• measuring, using one or more sensors of the microwave measuring apparatus, a set of measured values (XP={xPi,j}) for the plurality of products, wherein the set of measured values comprises one or more measured variables (j) corresponding to physical properties of the products;
• providing a corresponding set of reference variables (YP={yPi i-th reference variable}) representing known reference parameters of the products;
• determining, by the processor, at least one of the set of reference variables (Y) based on the one or more measured variables (xPi,j);
• generating an expanded matrix of the set of measured values for the plurality of products;
• determining a first set of calibration parameters (C′) comprising one or more weights
• (
• c
• j
• p
• )
• for one or more of the plurality of products (p), wherein the one or more of the plurality of products (p) is grouped within a first product family, wherein the one or more of the plurality of products in the first product family comprise an equal weight (cj) that is independent of a product;
• determining at least a second set of calibration parameters (C″) for a submatrix of the expanded matrix (X′) of the measured values to calibrate the microwave measuring apparatus with respect to a subset of the products;
• determining one or more sets of additional weights within the first product family, wherein products (p) having equal weights
• (
• c
• j
• p
• )
• are grouped into a sub product family within the first product family;
• determining weights for the plurality of products outside of the first product family, wherein products (p′) having equal weights
• (
• c
• j
• p
• ⁢
• ′
• )
• are grouped into another product family, until all weights are determined for the calibration of the microwave measuring apparatus;
• identifying relationships between the measured values across product families using the expanded matrix;
• and
• automatically adjusting one or more of first and second calibration coefficients of the microwave measuring apparatus based on the determined first and second sets of calibration parameters (C′, C″) and the identified relationships.