Agilent Technologies 4294A, Руководство по эксплуатации

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Chapter 5 109
Setting Measurement Conditions
Setting and Applying dc Bias
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range as narrow as possible without causing the error message “DCBIAS OVERLOAD”
(error number: 137) to appear. An initial dc bias range of 1 mA is recommended for the
first measurement when dc bias is applied.
NOTE
When you do not apply dc bias, always set the dc bias range to 1 mA, which is the preset
setting. Keeping this setting is especially important when you run through the sequence of
applying dc bias, turning off dc bias, and then performing a measurement.
Step 1. Press the
MEAS RANGE [ ]
key to display the dc bias range menu.
Step 2. Press the
1mA
key to select 1 mA as the dc bias range (preset state is 1 mA).
Step 3. Press the
return
key to return to the dc bias menu.
NOTE
Always set the dc bias range to 1 mA when you measure without applying dc bias.
5. Turning dc bias ON or OFF
Step 1. Press the BIAS on OFF (or BIAS ON off) key to make your selection (pressing the key
toggles your selection).
NOTE When the error message “CAUTION: DCBIAS OVERLOAD” (error number: 137)
appears in the instrument message area in the upper left part of the screen after turning dc
bias ON, follow the steps given in “6. Optimizing dc bias range” to set the appropriate
range for the dc bias.
Turning dc bias ON displays “DC BIAS ON” in the lower right area of the screen and also
shows the application status of the dc bias (indicating dc bias mode and whether dc voltage
exceeds the limits). See “dc bias status” on page 57 for details.
6. Optimizing dc bias range
Step 1. When the error message “CAUTION: DCBIAS OVERLOAD” (error number: 137)
appears after applying dc bias, increase the dc bias range by 1 step until the message
disappears. Then select the narrowest possible range.
Step 2. Press the
return
key to return to the dc bias menu. Note that the dc bias range currently
Softkey label Applied dc bias
DC BIAS on OFF
Off
DC BIAS ON off
On
dc bias range Key stroke
1 mA
1mA
10 mA
10mA
100 mA
100mA