Viewing the Calibration Values Return Loss Measurement
Agilent 8163A Lightwave Multimeter, Agilent 8164A Lightwave Measurement System, & Agilent 8166A Lightwave 
Multichannel System, Fourth Edition
143
Measuring the Insertion Loss
To measure insertion loss, you must measure the power transmitted through the 
DUT.
17 Connect the reference cable to a Power Sensor, for example, a Connector Pair, 
as shown in Figure 98.
18 As you have already, in Step 9 on page 141, set the [Ref] parameter to the 
power transmitted through the Reference Cable, the displayed power in dB is 
equal to the insertion loss.
Viewing the Calibration Values
Whenever the HP 81534A Return Loss Module is in the mainframe, the result 
field shows return loss. The calibration values used are either the most recently 
measured, where these are available, or default values.
If you are unsure of one or both of the calibration values you are using or if you 
have changed your measurement setup, make the appropriate calibration 
measurements again. 
1 Press [Menu]. Move to the <Show Calibration> menu item. The Calibration 
Parameters Screen appears, as displayed in Figure 99. The Calibration 
Parameters Screen shows current value for the following quantities:
– <RL>, the current Return Loss measurement,
– <Para>, the power measured during the termination calibration in dB 
relative to 1 µW,
– <Ref>, the power measured during the reference calibration in dB relative to 
1 µW, 
Figure 98 Measuring the Power Transmitted through the DUT (a Connector Pair)
81534A
Laser 
Source
8163A Lightwave Multimeter
Agilent 81101AC
Agilent 81101AC
Power 
Sensor
8163A Lightwave Multimeter
Agilent 81109AC
Agilent 81000AI
Agilent 81000UM
Measurement Cable