The high sensitivity of the NMR spectrometer JNM-3H, BH-2 (Japan electron optics laboratory Co. Ltd.) allows its use for express quantitative analysis of solids. One of the significant difficulties in this case is related to the recording of the calibration signal, which allows taking into account the analysis errors that arise as a result of uncontrolled changes in the hardware parameters of the spectrometer. First of all, these include changes in the goodness of the sensor circuit due to the variability of the electrical properties of the substance under study and changes in the gain of the receiver.

Nuclear magnetic resonance (NMR) is a new method of rapid quantitative analysis. The essence of the NMR phenomenon is the resonant absorption of electromagnetic radiation by a substance at transitions between the energy levels of atomic nuclei. If a substance containing nuclei possessing magnetic moments is placed in a constant magnetic field of intensity H and simultaneously in an alternating electromagnetic field oscillating with frequency f = γ/2π · H (γ is a constant characterizing the given type of nuclei), then under certain conditions the absorption of electromagnetic field energy by the substance will be observed. The change of this value at change of magnetic field strength in the resonance region is perceived and amplified by electronic equipment and recorded in the form of nuclear magnetic resonance signals carrying information about the substance under study. In quantitative analysis, the proportionality of the intensity of NMR signals to the content of nuclei under study in the sample is used.