Measuring air flow in an HVAC duct can be a tricky business. Paddle wheel and turbine flow meters introduce not only resistance but maintenance issue due to accumulated dust and debris.

Control variables - temperature, air flow or draughts, adequate supply of water. Care must be taken when inserting the plant shoot into the rubber tubing attached to the capillary tube and with ...

Under normal circumstances, the rate of water uptake gives a measure of the rate of transpiration. A simple potometer is a piece of capillary tubing to which a plant has been connected.

The equipment, however, yields some very serious data on water flow and depth in the Salt River, leading up to Roosevelt Lake. These measurements are done five to six times a year, but they’ll ...