General Description; Description; Operating Modes - Keithley 630 Instruction Manual

MODEL 630 POTENTIOMETRIC ELECTROMETER
GENERAL DESCRIPTION
SECTION 1.
GENERAL DESCRIPTION
l-l. DESCRIPTION
a.
The Keithley Model 630 Potentiometric Electrometer is a convenient, self-contained
potentiometer, It measures from 300 millivolts to 500 volts dc with 0.01% limit of error
from source resistances as high as lOlo ohms, and below
300 millivolts within 30 microvolts.
The upit need not be constantly calibrated or manually restandardized for a full year;
the limit of error is specified for one year.
in ut resistance of 1013 ohms,
F"'
Using the guarded, vibrating-reed null detector,
the Model 630 has a minimum (slewing)
on the l-millivolt to l-volt ranges, increasing to over
10 5 ohms at 1% off null and to infinite resistance at null.
With this extremely high in-
put resistance , .the Model 630 draws an absolute minimum of current to avoid loading and
polarizing the source.
c. Features for convenient use include:
5 in-line readout dials with automatically
lighted decimal points; one-volt,
one-milliampere output for full-scale deflection on all
ranges except the l-millivolt; input polarity switch;
floating operation up to 500 volts
off chassis ground; better than 60 db line-frequency rejection on the l-millivolt range.
Also, full guarding minimizes leakage problems.
l-2. OPERATING MODES. The Model 630 can be used as a five-dial potentiometer or as a
vibrating-reed electrometer.
As a potentiometer, it can measure from 300 millivolts to
500 volts full scale with *O.Ol% limit of error and from 1 millivolt full scale to 300
millivolts within 30 microvolts.
As a vibrating-reed electrometer, the Model 630 can
measure from 1 millivolt full scale to 500 volts within 23% full scale.
FIGURE 1.
Keithley Instruments Model 630 Potentiometric Electrometer.
1265R
1