NOYAFA NF-906A - Manual (Page 7)

REF
(4) Calibration Key
3.1 Information on LCD
After press key to start the meter, the following information
will be shown on LCD:
(1)if the meter is supplied by battery, the icon at the left bottom
will be ON. With the reduce of electric amount of battery, the
display segment of battery becomes less and less till empty.
(2)When connect with AC adapter, a icon will be lightened at
the middle of screen, at the same time, the electric amount icon
is ON as well.
(3)At the left lower position, it is a
icon.The Auto-off
function is activated simultaneously and the icon is lightened as
well, but if there is no operation, the meter will be shut down
15mins later.
“Auto-off”
3. Handling instruction
Press this key continuously to save the current power value as
reference value, which will be on the right upper corner of screen;
if just press this key shortly, it will be switched to relative power
measurement, while the reference power value will be shown on
the right upper corner of screen, and show the relative power value
between the current measurement and reference power, the unit is dB.
Your excellent helper in cable test! 05