EXFO PM-1600 High-Speed Power Meter User Manual
Page 25
![background image](/manuals/736489/25/background.png)
Acquiring Power Measurements
High-Speed Power Meter
15
Measuring Absolute Power
2. If necessary, press
λ
to select the appropriate wavelength from the
shortlist (see the section on viewing wavelength list on page 25).
Note: The wavelength may take some time to change on the display due to a low
refresh rate. To set the refresh rate, see Setting Refresh Rate on page 34.
3. Press dBm/W to display the absolute power of the signal received at
the detector port. The dBm/W button is also used to toggle between
dBm and W measurement units.
An absolute power measurement in negative W units indicates that
electrical offsets were improperly nulled. If so, repeat the offset nulling
(see Nulling Electrical Offsets on page 11).
Note: When - - - - - - - is displayed, the power level detected is below the lower
limit of the selected measurement range. When +++++++ is
displayed, the power level detected is above the upper limit of the selected
measurement range. See Setting Measurement Range on page 22.
When ! ! ! ! ! ! ! is displayed, the displayed data is in transition (range was
changed in power measurement mode, with Autorange selected).
When * * * * * * * is displayed, a programmed acquisition is running with
a high sampling rate.
Acquiring Power Measurements
High-Speed Power Meter
15
Measuring Absolute Power
2. If necessary, press
λ
to select the appropriate wavelength from the
shortlist (see the section on viewing wavelength list on page 25).
Note: The wavelength may take some time to change on the display due to a low
refresh rate. To set the refresh rate, see Setting Refresh Rate on page 34.
3. Press dBm/W to display the absolute power of the signal received at
the detector port. The dBm/W button is also used to toggle between
dBm and W measurement units.
An absolute power measurement in negative W units indicates that
electrical offsets were improperly nulled. If so, repeat the offset nulling
(see Nulling Electrical Offsets on page 11).
Note: When - - - - - - - is displayed, the power level detected is below the lower
limit of the selected measurement range. When +++++++ is
displayed, the power level detected is above the upper limit of the selected
measurement range. See Setting Measurement Range on page 22.
When ! ! ! ! ! ! ! is displayed, the displayed data is in transition (range was
changed in power measurement mode, with Autorange selected).
When * * * * * * * is displayed, a programmed acquisition is running with
a high sampling rate.