Keithley 2750, User Manual

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Model 2750 Multimeter/Switch System User’s Manual Basic DMM Operation 3-39
Frequency and period measurement procedure
NOTE Make sure the INPUTS switch is in the correct position. To use front panel
inputs, it must be in the “F” (out) position. For switching modules, it must be in
the “R” (in) position.
1. If a switching channel is presently closed (displayed), press OPEN to open it.
2. Perform one of the following steps to select function:
• Press FREQ to perform frequency measurements.
• Press SHIFT and then FREQ to perform period measurements.
3. Use the RANGE
Δ
and
∇
keys to select a measurement range consistent with the
expected AC voltage. Details on range are provided in Section 4.
4. Apply the AC voltage(s) to be measured.
CAUTION Do not apply more than maximum input levels indicated in
Figure 3-11 and Figure 3-12 or instrument damage may occur.
5. If using a switching module, perform the following steps to close the desired
channel:
a. Press the CLOSE key.
b. Use , ,
Δ
, and
∇
to key in the channel number and press ENTER. The
previously closed channel (if there is one) will open, and the specified channel
will close.
NOTE 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 if there is a channel closed.
2750-900-01.book Page 39 Wednesday, August 3, 2011 7:56 AM