Keithley 2790, Справочное руководство

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3-30 Model 2790 SourceMeter
®
Swich System Reference Manual
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While in the normal measurement state, you can use the and keys to close
channels. In general, each key press will open the presently closed channel and
then close the next higher or lower channel.
6. Observe the displayed reading. If the “OVERFLOW” message is displayed, select
a higher range until a normal reading is displayed. Use the lowest possible range
for the best resolution.
7. To measure other switching channels, repeat steps 5 and 6.
8. When finished, press OPEN (ALL) if there is a channel closed.
Continuity testing
The Model 2790 can test continuity using the 2-wire 1k
Ω
range. After selecting continu-
ity, you will be prompted to enter the threshold resistance level (1 to 1000
Ω
). When the
measured circuit is below the set threshold level, the instrument will beep and display the
resistance readings. When the measured circuit is above the threshold level, the message
“OPEN” will be displayed.
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The reading rate for continuity is fixed at FAST (0.1 PLC).
Limits and digital outputs cannot be used when testing continuity with the conti-
nuity (CONT) function. If you need to use these operations, use the
Ω
2 function
to test continuity.
Connections
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Switching module connections shown in this section are specifically for the 7702
module. Test connections for the 7751, 7752, and 7753 modules are provided in
the Model 2790 User’s Manual.
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When using the front panel inputs, the INPUTS switch must be in the “F” (out)
position. For switching modules, it must be in the “R” (in) position.
Front panel input
When using the front panel input terminals, connect the test leads to the INPUT HI and
LO terminals as shown in
Figure 3-12 A.
Model 7702 switching module
Connections for the Model 7702 switching module are shown in Figure 3-12 B. Since this
is a 2-wire ohms measurement, channels 1 through 40 can be used.