MBR5 User Manual
MBR5 Rev 007
22
Figure 9: Loss and Power Measurements
Dark Current Measurement
For loss and power measurements below -‐50 dBm, it is necessary to perform a
dark current measurement (measurement of power with no light).
1.
Ensure that the detector is covered, for example, that the detector
cap is on or the output connector is connected to the detector. This
dark current value will be subtracted from future loss and power
measurements.
2.
Press the DARK key. The key LED lights up to indicate that the user-‐
stored value of ID (the dark signal from extraneous sources) is used
to calculate the DUT loss or power.
If the detector is not properly covered, the message “Too Much Light!” is
displayed. If the ID value is not stored prior to a measurement, the last value
stored is used.
Measuring Power
In Power mode, absolute power measurements are displayed in dBm.
To perform power measurement of a DUT, make sure to perform the set-‐up
steps in the “SET-‐UP FOR LOSS AND POWER MEASUREMENTS” section on page
21 and then, follow these steps:
1.
Press the Power key to set the meter to Power mode.
2.
Press the
!
or
"
key to select the required output port.
3.
Press the
λ
key to select the wavelength at which the measurement
is to be performed.
4.
Clean the output connector of the measurement jumper and the
input connector of the DUT, and connect the two connectors.
5.
Connect the output connector of the DUT to the detector on the
front of the meter. The detector must be equipped with the
Measurement
Jumper
FC/APC
850
1310
1550
DETECTOR
CHANNEL
1
MENU
LOCAL
BR
BR
O
POWER
REF DARK
MBR5 Backreflection Meter
-0.00dB 1310
1
Absolute Power
I
O
