EXFO CT440 Series, User Manual

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Setting Up Your CT440 for Measurements
30
CT440
Performing User Referencing
Performing Wavelength Referencing
The CT440 should not encounter any shift in its wavelength accuracy between factory
calibrations.
The Wavelength Referencing area of the Referencing window enables you to improve the
accuracy of the wavelength referencing if needed by adding an offset to the factory
calibration.
The example method explained below uses a gas cell (not provided with the instrument) as
device-under-test (DUT), with known absorption lines within the wavelength range of the
CT440.
To perform wavelength referencing:
1.
Connect the instruments to the CT440 and specify them as follows:
1a.
To the TLS input port, connect a TLS source.
1b. Connect a gas cell as DUT.
1c.
In the Scan Parameters tab, specify the parameters of the connected TLS input
source.
2.
In the Scan Parameters area, specify a wavelength range corresponding to the gas cell
with a resolution setting of 1 pm (5 pm on CT440 with PDL option).
3.
Click the Scan button.
4. On the graph, manually measure the wavelength for a specific absorption line.
I
MPORTANT
User wavelength-referencing file is stored on the computer on which the CT440 is
connected. If you change computer you must perform the referencing again.