How to do Data hold with your GVDA GD155 Air Volume Tester Wind Speed Meter Digital Anemometer Handheld Measuring Wind Speed Tools for Meteorology Industry
To freeze a displayed reading, press the 
button(≤1 Sec.). The “H” icon will appear and the most recent reading will appear in the display. Press the 
button(≤1 Sec.) to exit the mode and return to normal mode .
