A method for detecting an inorganic anomaly in a biological material, comprising the steps of: irradiating the biological material with electromagnetic radiation of at least two different energy levels; measuring the amount of radiation transmitted through said biological material at said energy levels; determining, for each energy level, a transmission value through the biological material based on the radiation through said biological material; irradiating, before or after irradiation of said biological material, a reference material of a predetermined thickness with electromagnetic radiation of said energy levels; measuring the amount of radiation transmitted through said reference material at said energy levels; determining, for each energy level, a calibration reference value based on the radiation transmitted through said reference material; determining, for each energy level, a calibrated transmission value based on a ratio between said determined transmission value through the biological material for the energy level and said determined calibration reference value for the energy level; determining a material value based on a relationship between the calibrated transmission value for said energy levels; and determining the presence of an anomaly in said biological material based on a comparison between the determined material value and an expected material value for said biological material, wherein the material value is based on a K-value for said biological material, said K-value being calculated as: K = ln N 01 / N 1 ln N 02 / N 2 wherein N 01, N 02 are the calibrated reference values for the transmission at the two energy levels and N 1, N 2 are the transmission values through the biological material at said energy levels, and presence of an anomaly in said biological material is determined based on a comparison between said calculated K-value and an expected K-value for said biological material, characterized in that the biological material is transported on a conveyor line, wherein the biological material is irradiated with electromagnetic radiation of at least two different energy levels in a plane substantially perpendicular to a direction of advancement of said conveyor line, the amount of radiation transmitted through said biological material at said two energy levels being determined for a plurality of radiation paths penetrating said biological material in said plane substantially perpendicular to the direction of advancement of said conveyor line, and wherein said conveyor line has a width in a direction perpendicular to the direction of advancement, wherein said radiation paths are distributed throughout the width of said conveyor line; in that the inorganic anomaly is an inorganic object of at least one of stone, metal and glass. irradiating the biological material with electromagnetic radiation of at least two different energy levels; measuring the amount of radiation transmitted through said biological material at said energy levels; determining, for each energy level, a transmission value through the biological material based on the radiation through said biological material; irradiating, before or after irradiation of said biological material, a reference material of a predetermined thickness with electromagnetic radiation of said energy levels; measuring the amount of radiation transmitted through said reference material at said energy levels; determining, for each energy level, a calibration reference value based on the radiation transmitted through said reference material; determining, for each energy level, a calibrated transmission value based on a ratio between said determined transmission value through the biological material for the energy level and said determined calibration reference value for the energy level; determining a material value based on a relationship between the calibrated transmission value for said energy levels; and determining the presence of an anomaly in said biological material based on a comparison between the determined material value and an expected material value for said biological material, wherein the material value is based on a K-value for said biological material, said K-value being calculated as: K = ln N 01 / N 1 ln N 02 / N 2 wherein N 01, N 02 are the calibrated reference values for the transmission at the two energy levels and N 1, N 2 are the transmission values through the biological material at said energy levels, and presence of an anomaly in said biological material is determined based on a comparison between said calculated K-value and an expected K-value for said biological material, characterized in that the biological material is transported on a conveyor line, wherein the biological material is irradiated with electromagnetic radiation of at least two different energy levels in a plane substantially perpendicular to a direction of advancement of said conveyor line, the amount of radiation transmitted through said biological material at said two energy levels being determined for a plurality of radiation paths penetrating said biological material in said plane substantially perpendicular to the direction of advancement of said conveyor line, and wherein said conveyor line has a width in a direction perpendicular to the direction of advancement, wherein said radiation paths are distributed throughout the width of said conveyor line; in that the inorganic anomaly is an inorganic object of at least one of stone, metal and glass.