Basic Input Connections - Keithley 194 Instruction Manual

GETTING STARTED
2.54 Measurement Procedure
Use the following basic procedure to connect the instru-
ment to a voltage source and display readings on the front
p3"d.
1. Turn on the instrument power and allow a one-hour
warm up period for rated accuracy. Verify that the in-
strument goes through its normal power up procedure,
as described in paragraph 2.4.
2. Press SHIFT RESET to make certain that the factory
default configuration is placed in effect, or program your
own operating modes, as discussed in paragraph 2.5.3.
3. If your instrument is equipped for dual channel opera-
tion, select either channel 1 or channel 2 by pressing
the CHANNEL button. The selected channel number
will appear in the right most digit of the display for
either of the sin&-channel modes.
4.
5.
6.
7.
8.
Select a range that is consistent with the anticipated
measurement by using the uprange or downrange but-
tons, or use autoranging and allow the instrument to
select the best range.
Connect a suitable BNC cable to the VOLTAGE INPUT
jack for the selected channel.
Connect the other end of the cable to the voltage source
to be measured, as shown in Figure 2-8. Remember that
the cable shield is connected to input common, and
must not be floated more than 30V RMS above chassis
ground.
Place the unit in the continuous trigger mode (CONT
indicator on) and then press TRIGGER to ensure that
the unit is processing readings.
At this point, the instrument should display the voltage
level being measured. An OFLO error message will be
displayed if the input signal is above the selected range,
in which case the instrument should be moved uprangc.
BNC CABLE
WARNlNG: MAXIMUM COMMON MODE VOLTAGE 1""
CAUTION: MAXIMUM iNP"T 250" PCAK, 2 ,O~".HZ
Figure
2-8.
Basic Input Connections
2.6 SAMPLES, MEASUREMENTS AND
READINGS
Throughout this manual you will encounter references to
samples, measurements, and readings. .I'he follo\ving
paragraphs define and discuss these terms in order t<>
clarify them.
2.6.1 Definitions
Sample-an individual AID cmwersion resulting in d single
unit of digitized binary data.
2-15