How it Works

Flow Quik works with a vacuum source that you supply. This can be your shop vacuum or a more powerful source. (See Flow Quik Tips & Advice for hints on vacuum sources.) It does not control the amount of vacuum (commonly called "depression"). Instead, it measures the depression and the flow, and then adjusts the displayed flow to what it would be at the standard depression. You select the standard depression by the range knob on the front panel. The method Flow Quik uses to calculate this adjustment is a well established principle of fluid dynamics, and is recommended by the largest flow bench manufacturer (Big Blue, and we don't mean IBM).

Flow Quik uses an averaging velocity tube to measure flow. The velocity tube and the orifice (commonly used in flow benches) are both members of a broader classification of flow measuring devices called differential producers. With both of these, the flowing air produces a pressure drop that is proportional to the square of the flow. The combination of this nonlinear response and high pressure drops gives the orifice a limited range. This is why flow benches need several orifices of different sizes.

Flow Quik's averaging velocity tube can measure a broader range than an orifice because it's a low constriction design has a low pressure drop. It's range can be further extended because it does require that depression be controlled. Heads that flow beyond its normal capacity can be tested at a lower depression. Flow Quik senses the lower depression and corrects the flow figure to what it would be if the depression were at the standard value.