Influence of apparatus factors on the results of measures of oil content, moisture, and percentage of oleic acid in sunflower seeds by a NMR-method

The aim of the work is to study impact of appara-tus factors on the results of measurements of qualitative traits of sunflower seeds (oil content, moisture and weight percentage of oleic acid) using NMR-analyzer oil content and moisture AMV-1006M. The primary apparatus factor that may influence on the measurements results are stability and accuracy of maintaining of optimal resonance conditions for hydrogen nucleuses in an analyzed sample and stability of radioimpulse signals energy. As an objective for research there were chosen sunflower seeds samples with the following traits: oil content 36.0-51.5%, moisture 4.5-14.7% and oleic acid content in oil 30-87%. Deviation of the resonance conditions from the optimal meanings and deviation of source voltage of amplifier output stage of energy were created artificially, by means especially developed control program of the resonance conditions and energy. Detuning of resonance conditions within a range ±4∙10-5 оf relative units and energy of power amplifier within in a range ±4% did not effected the measured meanings of oil content and moisture of sunflower seeds, and lies in error limits of the used method. Detuning of the resonance conditions influenced significantly on measured meaning of oleic acid content in oil of sunflower seeds. In average, detuning on a value ±10-5 of relative units leads to an error up to 5.0-5.5%. Detuning of an energy amplifier up to 1% leads to variation of the measured meaning of oleic acid content in average on 3.5-4.0%. The optimal meanings of apparatus factors to obtain the results on measuring of percentage of oleic acid in sunflower seeds with specified error are provided by stabilization of the resonance conditions within no more than ±2•10-6 оf relative units and stability of energy of power amplifier no more than ±0.2%.