Keithley 6517A, Руководство пользователя

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Front Panel Operation
2-46
ZERO CHECK HOP and AUTO DISCHARGE HOP
Using the zero check feature (going from the enabled state to
the disabled state) causes a sudden change in the charge
reading and is known as zero check hop. This sudden change
in charge also occurs when the auto discharge feature resets
the charge reading to zero. This hop in charge can be elimi-
nated by taking a reading the instant zero check is disabled
or when an auto discharge occurs, and subtracting it from all
subsequent readings. A better way to deal with this hop in
charge is to enable REL immediately after zero check is dis-
abled or when auto discharge resets the charge reading. This
action nulls out the charge reading caused by the hop.
2.9 Voltage source
The built-in, bipolar, 1W voltage source of the Model 6517A
can source up to ±1000V (the V-Source may reach ±1010V
if it is uncalibrated). The two voltage ranges of the voltage
source are summarized in Table 2-14.
WARNINGS
The maximum common-mode voltage for
the V-Source is 750V peak. That is, the
voltage between V-Source LO and earth
(chassis) ground must never exceed 750V
peak, and the voltage between V-Source HI
and earth (chassis) ground must never ex-
ceed 1760V peak. Exceeding these values
may create a shock hazard. See paragraph
2.4.5 for information on floating the V-
Source.
With the voltage source in operate, the pro-
grammed voltage value (possibly hazard-
ous) will be applied to the output terminals
of the voltage source. Keep the voltage
source in standby until ready to safely
source voltage. NEVER make or break any
connections with the instrument in oper-
ate. The voltage source is in operate when
the VOLTAGE SOURCE OPERATE indi-
Table 2-14
V-Source ranges
Range
Maximum output
Step size Voltage Current
100V
1000V
±100V
±1000V
±10mA
±1mA
5mV
50mV
cator light is on. To place the voltage
source in standby, press the OPER key.
This key toggles the V-Source between op-
erate and standby.
NOTE
Capacitive inputs increase preamplifier
noise, resulting in noise across the voltage
source terminals. See page 2-29 for details,
V-Source configuration
Operations to configure the V-Source are performed from the
V-Source configuration menu which is summarized in Table
2-15. The CONFigure V-SOURCE menu is displayed by
pressing CONFIG and then OPER (or
▲
or
▼
). Paragraph
2.3.5 summarizes the rules for navigating through the menu
structure. The various items of this configuration menu are
explained in the following paragraphs.
2.9.1 Sourcing options
The voltage source can be used as an independent source or
it can be internally connected to the ammeter to force voltage
measure current (FVMI).
Independent source —
When used as an independent
source, voltage is available at the V-SOURCE HI and LO ter-
minals on the rear panel (see Figure 2-38). In this configura-
tion, the V-Source functions as a stand-alone voltage source.
The V-Source is isolated (>1G
Ω
) from the measurement cir-
cuits of the Model 6517A when V-Source LO is not internal-
ly connected to ammeter LO (see Ammeter LO to V-Source
LO Connection).
Table 2-15
CONFIGURE V-Source menu structure
Menu item Description
RANGE Select V-Source range (100V or
1000V).
V-LIMIT
CONTROL
LIMIT-VALUE
Voltage limit menu:
Use to enable or disable V-Limit.
Set maximum absolute output
limit.
RESISTIVE-LIMIT Enable or disable resistive I-Limit.
METER-CONNECT Enable or disable internal V-Source
LO to ammeter LO connection.