wavelengths, the current choice of wavelength will
appears on the LCD
4) REF ：press REF key to enter relative
measurement mode and it has 3 working modes:
A) Directly enter the relative measurement: in
absolute measurement mode, press REF to enter
the relative measurement. Now the Ref value shows
the previous saved power values.
B) Save the reference value ：when enter the
relative measurement mode, press REF for 2
seconds to save the current absolute power value as
REF value and show the relative power value in dB
unit
C) Enter the relative measurement mode and save
current reference value: in the absolute
measurement mode, press REF for 2 seconds to
enter the REF measurement mode and save the
current value as REF value which will appears in Ref
position. Now the value in dB unit on the LCD and
the vale means the difference value between the
measurement value and REF value, meanwhile, the
REF value will displays in the REF position.
5) Backlit is on when turning on the unit. It will turn off
one minute later. Operators can press any key to
make backlit for another one minute.
