Abstract
A continuous flow system for use with an unmodified Varian A‐69A NMR spectrometer is described. Normal sample spinning is preserved, and high resolution is maintained. The transfer time of the sample stream between a reaction cell placed in a variable external magnet and the spectrometer may be made as short as 1 sec. The apparatus has been used to obtain chemically induced dynamic nuclear polarization (CIDNP) spectra during the photolysis of di‐t‐butyl ketone in low magnetic fields.