Abstract: A sample with unknown concentrations of elements is placed in a first step into a spectrometer and the intensities I1, I2, . . . , In of the sample for the component elements are measured while the concentrations of the sample are determined, or—alternatively—a sample with known concentrations of the substances C1, C2, . . . , Cn is placed into the spectrometer and the intensities of the sample are determined. The fictive theoretical intensity values, the I100%-values, for the component elements are calculated in a second step with the aid of the determined concentrations and the measured intensities I1, I2, . . . , In, or with the aid of the determined intensities and the known concentrations C1, C2, . . . Cn. New I100%-values for the corresponding elements are calculated in a third step with the aid of standards with known concentrations, the intensities of which standards are measured.

Abstract: Process of placing a sample of known concentrations of known elements in a spectrometer; measuring the intensity II, I2 . . . In of the different elements included in the sample, by relating known concentrations C1, C2 . . . Cn for the elements included in the sample to the measured intensities II, I2 . . . In so as to calculate a fictive intensity for a 100%-pure element for each of the elements included; calculating calibration constants K1, K2 . . . Kn for each of the elements as the relationship between measured intensity II, I2 . . . In and the calculated intensity of respective 100%-pure elements; placing a sample of unknown concentrations of the elements in the spectrometer and reading-off the intensity of the different elements; and calculating the concentration of respective elements in the last mentioned sample as the measured intensity multiplied by respective calibration constants for the elements present in the sample.