How To Set The Wavelength; How To Set The Calibration Offset - Keysight N774-C Series User Manual

How to Set the Wavelength

How to Set the Calibration Offset

Keysight N774-C & 8162-C Series User's Guide
Where,
P is the power value returned in dB,
dB
P is the input signal level in Watts, and
input
Pref is the chosen reference power value in Watts.
This is the wavelength value of the signal to be measured. The responsivity
of the Power Meter varies with wavelength. For accurate absolute power
measurement, you need to input the wavelength of the optical input. For
relative power measurements, this setting is not critical.
There are two ways to set the wavelength value:
• You can set the wavelength directly on clicking the Wavelength button,
see Display Wavelength and Power
• You go the Settings > Measurement Settings and then set the
wavelength.
This is a calibration offset that you can enter to compensate for external
optical circuitry, for example, an attenuator, switch, or a 3 dB coupler. The
calibration offset, [Cal], is automatically subtracted from the input signal,
as expressed in dB.
( )
P dBm =
measured
where,
P is the adjusted value of the signal read in dBm,
measured
P is the input signal level in dBm, and
input
CAL is the calibration offset in decibels (dB).
on page 75, or
( ) CAL dB (
P dBm –
input
User Interface Reference
)
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