DSP-FOM
Fiber Optic Meter
6
Step 5: 1550 nm Fine Calibration
Adjustment
5-1. Set the switch on the FOM to the 1550 nm
position.
5-2. Set the 1550 nm light source to -10 dBm
±
0.05 dBm. Use the reference power meter to
measure the source output power level.
Record this level as Pin for use in step 5-4.
5-3. Connect the 1550 nm light source to the
FOM.
5-4. Use Pin from step 5-2, Vref from step
2-5, and the transfer function below to
calculate Vo:
( )
(
)
9R
=
× −
+
V
53 dBm
P
3 dBm
ref
in
5-5. Measure between DBout at U2 pin 7 and the
analog ground reference at U1 Pin 4. Adjust
R3 for Vo (as calculated in step 5-4)
±
0.0005 V.
Step 6: Verifying Calibration
6-1.
Follow the procedures given in the earlier
section "Performance Tests".
6-2.
Apply insulating varnish, such as red GLPT,
to R1, R2, R3, and R10.
6-3.
Reassemble the FOM as described in the
earlier section "Disassembling and
Reassembling the FOM".
Parts and Accessories
Replacement parts (Table 2) and accessories
(Table 3) are available from Fluke.
Table 2. Fluke Replacement Parts for the DSP-FOM
Description
Fluke Part
Number
DSP-FOM Plastic Case Assembly
616034
Battery Door
200474
PD1: Germanium Photodiode, 1 mm
602778
Table 3. Accessories for the DSP-FOM
Description
Fluke Part
Number
ST to ST Multimode Patch Cable, 1m
617453
ST to ST Cable Adapter
602810
Carrying Case
616091