Flow-Through NMR Probes

Johnson noise. Syn. thermal noise. The electrical noise caused by the Brownian motion of ions in a conducting material, e.g., a wire. This type of electrical noise varies with temperature. 

Shot noise. Electrical noise resulting from the movement of individual charge quanta, like raindrops on a tin roof. With a low flux, individual drops are heard in a random pattern, but as the flux increases, the impact of the individual drop is lost in the continuum of many drop impacts per unit time. 

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Another most exciting new tool for the analysis of complex polyolefins is the direct coupling of high-temperature liquid chromatography and H-NMR. Such equipment became available only recently when a high-temperature flow-through NMR probe was introduced by Bruker. The construction and experimental setup of the LC-NMR coupling is described in detail by Hiller et al. [130]. In brief, the NMR flow probe can operate at temperatures up to 150°C. The probe has an active flow cell with a volume of 120 pL. It is a dual inverse H/ C probe with pulse field... 

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