HP 8153A - Page 57

Using with a One Sensor Instrument
(dB) changes the display to show the result as a relative value with respect to
the stored reference. The reference-indicator shows A/REF or B/REF. Tb see the
reference, use (Paraml . 'Ib set the reference, use (Paraml or (Disp->Ref| .
^display{(^^) “ ^measured . .
Where,
Pdispiay is the displayed, relative power,
Pmeasured is the absolutG power-ievel (see “CAL”), and
REF is the reference.
The dBm/W Key
This key changes the display to show results in dBm or in Watts.
If the results are in dB, {dBm wl changes the display to showing the result as
dBm or Watts.
If the results are in dBm, (dBm wl changes the display to showing the results in
Walds.
If the results are in Watts, (dBm wl changes the display to showing the result in
dBm.
The Zero Key
The (Zero) works with sensor modules. The function of (zii7) is to remove any
electrical offset in the sensor circuitry.
The instrument measures by converting optical power to electrical power, and
then measuring the electrical power. An electrical offset is power that is always
present, even if there is no light at the input. If this offset is not removed, it
will affect the results.
(Zero) m easures the electrical power when there is no light at the input. The
instrument uses this value to remove the offset from all further incoming
signals.
Local Control • Measure Mode 2-9