TY - CONF A1 - Meyer, Klas A1 - Bornemann-Pfeiffer, Martin A1 - Lademann, J. A1 - Kraume, M. A1 - Maiwald, Michael T1 - Contributions Towards Variable Temperature Shielding for Compact NMR Instruments N2 - The application of compact NMR instruments to continuously flowing samples at higher temperatures or exothermically reacting mixtures is limited by the temperature sensitivity of permanent magnets. Typically, such temperature effects directly influence the achievable magnetic field homogeneity and hence measurement quality. The internal-temperature control loop of the magnet and instruments is typically not designed for compensation of such effects. Passive insulation is restricted by the small dimensions within the magnet borehole. Here, we present a design approach for active heat shielding with the aim of variable temperature control of NMR samples for benchtop NMR instruments using a compressed airstream which is variable in flow and temperature. Based on the system identification and surface temperature measurements using an optical thermo-graphy setup, a model predictive control was set up to minimize any disturbance effect on the permanent magnet from the probe or sample temperature. This methodology will facilitate the application of variable-temperature shielding and, therefore, potentially extend the application of compact NMR instruments to flowing samples at higher temperature than the permanent magnet. T2 - 18. Kolloquium AK Prozessanalytik CY - Krefeld, Germany DA - 27.11.2023 KW - Thermostating KW - Benchtop-NMR KW - NMR spectroscopy KW - Process Analytical Technology PY - 2023 AN - OPUS4-58970 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -