These two properties of the capillary tube columns impose severe restrictions on the type of detector suitable for observing the emergence of vapour from the column. The smallness of the load ...

There is no net movement of water in any direction as the concentration is equal on both sides so the level of water in the capillary tube remains the same.

A simple potometer is a piece of capillary tubing to which a plant has been connected. The water uptake is measured by recording the time taken for a bubble in the tube to move a set distance.