Magnetic stirrer that reverses direction on an interval from 30 seconds to 3 minutes, with Speedsafe. 2.5 L, 115 V.
HI302N-1
This is the heavy-duty Hanna stirrer with one addition: the drive reverses direction automatically on a set interval, anywhere from 30 seconds to 3 minutes.
Reversal exists because continuous one-way stirring builds a stable vortex, and a stable vortex is a poor mixer. Liquid circulates in fixed paths, dense material settles into the quiet zone at the vortex wall, and a suspension that looks well stirred is stratified. Reversing collapses the vortex and forces the flow pattern to rebuild, which is what actually redistributes solids.
That matters for suspensions held over hours — settling solids, slow dissolutions, sample preparation where a nominally homogeneous aliquot is drawn at intervals. It matters much less for a solution that dissolves in two minutes, where the plain heavy-duty model is the better value.
| Specification | Value |
|---|---|
| Maximum stirring capacity | 2.5 litres |
| Speed range | 100 to 800–1000 rpm |
| Reverse interval | 30 seconds to 3 minutes |
Catalog HI302N-1, 115 V, with Speedsafe decoupling protection carried over from the standard model.