Question:
How do you turn on the sound function?
Answer:
After turning on the meter, simply press the LIGHT button to activate the sound function. Please note that keeping the sound off along with the light, will conserve battery power.
Question:
Why does the e-field reading increase when the USB cable is attached to the PC for datalogging?
Answer:
The long wire of the USB cable is coupling the E-field noise signal from the other side of the cable (or the signal induced from on air noise along the cable to the meter.
The E-field is very sensitive to objects nearby especially the metal wires so keep the cable as short as possible. In professional applications a optical fiber is used to avoid the interference caused by metal cables.