Keithley 6512, Instruction Manual

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1.1 Introduction
The Keithley Model 6512 Programmable Electrometer is a
highly sensitive instrument designed to measure voltage,
current, charge, and resistance. The measuring range of the
Model 6512 is between 10µV and 200V for voltage mea-
surements, from 0.1fA and 20mA for current measurements,
between 0.1
Ω
and 200G
Ω
for resistance measurements, and
in the range of 10fC and 20nC in the coulombs mode. Very
high input impedance and extremely low input offset current
allow accurate measurement in situations where many other
instruments would have detrimental effects on the circuit be-
ing measured. A 4
½
-digit display and standard IEEE-488 in-
terface allow easy access to instrument data.
1.2 Features
Some important Model 6512 features include:
• Ideal for low-current measurements—Current resolu-
tion of 0.1fA makes the Model 6512 ideal for very low-
current measurements.
• 4
½
-Digit Display—An easy-to-read front panel LED
display includes a 4 ½ -digit mantissa plus a two-digit
alpha or numeric exponent.
• Auto-ranging—Included for all functions and ranges.
• Digital Calibration—The instrument may be digitally
calibrated from the front panel or over the IEEE-488 bus.
• Zero Correct—A front panel zero correct control allows
you to cancel internal voltage offsets, optimizing accuracy.
• Baseline Suppression—One-button suppression of a
baseline reading is available from the front panel or
over the IEEE-488 bus.
• One-shot Triggering—A front panel control for trigger-
ing one-shot readings from the front panel is included.
• Selectable Guarding—A selectable driven cable guard
is included to minimize the effects of leakage resistance
and stray capacitance.
• Standard IEEE-488 Interface—The IEEE-488 interface
allows full bus programmable operation of the Model
6512.
• Analog Outputs—Both preamp and 2V full-range ana-
log outputs are included on the rear panel.
• 100-Point Data Store—An internal buffer that can store
up to 100 readings is accessible from either the front
panel or over the IEEE-488 bus.
• Minimum and maximum data points can be stored and
are accessible from the front panel or over the IEEE-
488 bus.
1.3 Warranty information
Warranty information for your Model 6512 may be found in-
side the front cover of this manual. Should you need to use
the warranty, contact your Keithley representative or the fac-
tory for information on obtaining warranty service.
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General Information