Related link: Setting Up DOSY Experiments

Related link: Dynamics Center

Convection can be quite bad in low-viscosity solvents such as CDCl3 and acetone-d6. It yields a diffusion coefficient (D) that is artificially larger than the actual value and the apparent D could vary with varying d20. To minimize convection, please follow these suggestions:

1. Use higher viscosity solvents if possible. D2O and DMSO have much less convection than CDCl3.
2. Minimize sample height, which will minimize vertical temperature gradient and thus reduce convection. My recommendation is 2.5cm of sample height, which reduces convection while do not sacrifice spectral resolution too much (peak width of 1.5-2 Hz can be achieved).
3. Recommend use 3mm tubes if you must use CDCl3 or acetone-d6 as solvents. Reducing cross section area of the liquid can drastically reduce convection.