Moisture determination, field samples

The kind of NMR data required (e.g. signal amplitudes, relaxation information or chemical shift information with limited spectral resolution) plays a significant role in defining the design criteria for both hardware and software components. In common practice, in low-resolution NMR the concern is with the analysis of the NMR signal in the time domain (FID) and the characterisation of the physical structure of the bulk sample. The global characterisation of the sample in terms of molecular dynamics is key to successful use of low-field NMR. Relaxation information should provide rapid, reliable quantitative information for improved process control. The relaxation behaviour can provide extremely useful information on various aspects of mobile phases, e.g. moisture determination. 

Determine the moisture content at field capacity after dr3ring the soil sample in the oven. 

NIR spectroscopy has been used for more than 30 years in the x)d industry and agriculture. The main applications are determination of moisture and characterization of other compounds, e. g. protein content in grain and milk products. Usually diffuse reflection is measured because then the samples need not be prepared extensively. Compared to wet chemical analysis or other instrumental methods of analysis, NIR in particular allows rapid detection even under field conditions. Some basic characteristic wavelengths are fisted in Tab. 6.4. 

Part of this decision is determined by the quality of the soil including the pH, the amount of moisture, and the nutrient content in the soil. He begins by sampling the soil and performing a few chemical tests on the soil. John determines that several of his fields need additional fertilizer before the crops can be planted. 

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