HP 8153A - Page 68

Warning
0
Do not look into the end of an optical cable attached to a
laser output when the device is operational.
Note
Do not disconnect the fiber from the source when making a loss
measurement. A small change in the coupling at the source can
introduce large errors into your mejisurement.
Once you have taken the reference, you can place the device under test into the
system.
Figure 3-2. Measuring the Loss of a Device Under Test (DUT)
Do not stop and restart the application as you insert and change devices
under test. Every time you start the application, the instrument takes a
new reference. You can switch the source off and on without disturbing the
reference value. Do this to avoid exposure to laser radiation when you are
changing the device under test.
While the application is running, the revSult field shows the loss, in dB, and the
character field shows the reference, in dBm. 1 indicates the result field and 2
indicates the character field in Figure 3-3. If you are using both wavelengths
of a dual wavelength source, the loss and reference for both wavelengths are
displayed. The loss and reference for the lower wavelength is shown on the
left. The loss and reference for the higher wavelength is shown on the right.
34 Local Control ■ Menu Mode