Without a doubt, the main advantage of this handheld cup vane air velocity meter is that it doesn't need to be held exactly in the direction of the wind. Air velocity meters with impellers typically have to be held exactly in the direction of the air flow to take accurate measurements. However, this cup vane air velocity meter's system is so sensitive that it responds to the smallest of air currents. To perform a correct measurement with the PCE-A420 cup vane air velocity meter: First turn the meter on, then hold the meter vertically so the cups can rotate until the wind velocity is displayed. In the following picture you can see how to measure wind speed with the PCE-A420 cup vane air velocity meter.

As previously stated, different measurement units can be selected with the PCE-A420 cup vane air velocity meter: m/s, km/h, knots, ft/min and mph. To change measurement units in the PCE-A420 cup vane air velocity meter, you must press the key Data Hold until the desired unit is displayed, then depress the key. You can save the unit in the memory of the PCE-A420 cup vane air velocity meter to be displayed every time the meter is turned on. If the messages Hold or REC appears in the display, you cannot change the measurement units. Moreover, you could fix a value in the PCE-A420 cup vane air velocity meter by pressing the Hold key during the measurement. To deactivate this function please press the Hold key again.