Keithley 3720 User Manual page 201

3706 Multimeter / Switch System
DC Notes
DC Measurement Characteristics
DC Volts:
A-D LINEARITY:
1.0 ppm of reading + 2.0 of range.
INPUT IMPEDANCE:
Selectable >10G:// <400pF or 10M: r1%.
100mV – 10V Ranges:
10M: r1%.
100V – 300Vranges:
Input Bias Current:
<50pA at 23qC with dmm.autozero=dmm.OFF or
dmm.inputdivider=dmm.ON.
Common Mode Current: <500nA peak-to-peak for ”1MHz.
For DCV r1qC and <10minutes,
Autozero OFF Error:
Add r(8ppm of reading + 5PV).
Input Protection:
300V all ranges.
Common Mode Voltage
: 300V DC or 300Vrms (425V peak for AC waveforms)
between any terminal and chassis.
Resistance:
MAX 4W: LEAD RESISTANCE:
for 10: o 1k: ranges; 1k: per lead for all other ranges.
For Dry Ckt
.
MAX 4W: LEAD RESISTANCE:
per lead for 10: o 100: ranges; 50: per lead for 1k: o 2k: range.
INPUT IMPEDANCE:
1: – 100: Ranges: 99k: r1% // <1PF.
1K: – 2K: Ranges: 10M: r1% // <0.015PF.
: Selectable on 4W: 1: o10k: ranges.
OFFSET COMPENSATION
: Selectable per channel. 1.5uA, r20% sink
OPEN LEAD DETECTOR
current per DMM SHI and SLO lead. Default on.
CONTINUITY THRESOLD
: Adjustable 1 to 1000:.
For 2W: r1qC and <10minutes,
Autozero OFF Error:
Add r(8ppm of reading + 0.5m: for 10: and 5m: for all other ranges).
INPUT PROTECTION: 300V all ranges.
DC Current:
: For r1qC and <10minutes,
Autozero OFF Error
Add r(8ppm of reading + range error). Refer to table below.
Range 3A 1A 100mA
Shunt
Resistance
0.1: 0.1: 1:
guarantee
by design
Burden
<1.8V <0.6V <0.4V
Voltage
Burden
Voltage
<2.4V <1.2V <0.4V
with 3721
card
Autozero
OFF
50PA 50PA 5PA
"of range"
Error
INPUT PROTECTION : 3A, 250V fuse.
Thermocouples:
CONVERSITION:
ITS-90.
REFERENCE JUNCTION
: Internal, External, or Simulated (Fixed).
: Selectable per channel. Open >1.15k r50:.
OPEN LEAD DETECTOR
Default on.
COMMON MODE ISOLATION
waveforms), >10G: and <350UF any terminal to chassis.
End dc
5: per lead for 1: range, 10% of range
0.5: per lead for 1: range; 10% of range
10mA 1mA 100PA 10PA
10: 100: 1k: 6k:
<150mV <130mV <105mV <61mV
<150mV <130mV <105mV <61mV
0.5PA 50KA 5KA 0.85KA
: 300V DC or 300Vrms (425V peak for AC
DC Notes
1.
20 % overrange except 1% on 300V and 3.33% on 3A.
2. ±5% (Measured with 10M: input Resistance DMM, >10G: DMM on 10M: and 100M: ranges). Refer to table
for other 2W/4W configurations. For Dry Circuit, +20%, <1mV with dmm.offsetcompensation=ON for 100: o
2k: ranges.
Range 2W
1, 10: 8.2V
100, 1k: 13.9V
9.1V
10k:
100k, 1M: 12.7V
10M, 100M: 6.4V
3. Relative to calibration accuracy.
4. Add the following additional uncertainty:
Card "of range"
3720, 3721 , 3730
3722
3723
Specifications are for 4-wire :, 1:o 100: with offset compensation on. Model 3700 plug-in cards with LSYNC
5.
and offset compensation on. 2-wire : specifications are for dmm.connect=dmm.CONNECT_ALL.
For 2-wire :, add the following to "ppm of range" uncertainty,
700m: with dmm.connect=dmm.CONNECT_TWO_WIRE, 100m: with REL, and 1.5: without REL.
1: range is 4-wire only.
6.
Test current with dmm.offsetcompensation=OFF, (r 5%).
7.
Add the following to "ppm of reading" uncertainty when using 3700 plug in cards in Operating Environment
•50%RH.
Card
3720, 3721, 3730
with MTC D-Shell connector
3722, 3723 and
3720, 3721, 3730 with
–ST screw terminal module
3700 plug in cards Operating Environment: Specified for 0qC to 50qC, ”70%RH at 35qC.
For 4-wire : only, offset compensation and LSYNC on. For Models 3722 and 3723, 10: o2k: ranges only.
8.
9.
Includes Analog Backplane 15-pin rear panel connector. For 3721, refer to DC Current table for additional
uncertainties.
10.
For L On, line frequency +/-0.1 %.
SYNC
nPLC
L On NMRR
SYNC
L Off NMRR
SYNC
11.
For 1kohm unbalance in LO lead. AC CMRR is 70dB.
nPLC 5
CMRR 140 dB
12.
For L On.
SYNC
13.
Reading rates are for 60Hz (50Hz) operation using factory defaults operating conditions dmm.reset("all"),
Autorange off, Limits off, dmm.autodelay=dmm.ON, dmm.opendetector=dmm.OFF, format.data.=format.SREAL,
DCV=10V, 2W/4W=1K:, DCI=1mA, Dry-Ckt=10:, ACI=1mA, and ACV=1V. For Dry-Ckt 100: and 2K:,
60rdg/s max with offset compensation OFF and 29.5rdg/s max with offset compensation ON. For Temperature
reading rates use DCV for T/C, 2W: for Thermistor, and 4W: for RTD. Speeds include measurements and binary
data transfer out the Enet, GPIB or USB.
14.
DMM configured for single reading, dmm.measurecount=1 and print(dmm.measure()).
15.
DMM configured for multi-sample readings and single buffer transfer, dmm.measurecount=1000,
buf=dmm.makebuffer(1000), dmm.measure(buf), and printbuffer(1, 1000, buf).
dmm.autozero=dmm.ON. RMS Noise using low thermal short for DCV, 2W:, 4W:, and Dry-Ckt :. For DCI,
16.
dmm.connect=dmm.CONNECT_NONE or 0. Includes Model 3721 card accuracies.
17.
For DC, dmm.nplc=0.0005. For AC, dmm.detectorbandwidth=300, dmm.nplc=0.0005. For ACI,
dmm.autodelay=dmm.ON (50ms), max rate is 50ms and ACV dmm.autodelay=dmm.ON (50ms), max rate is 50ms.
18.
Speeds are within same Mux bank. Add an additional 8msec when changing banks or slots.
19.
When properly zeroed using REL function.
Ocomp
4W-
4W Kelvin 4W
8.2V 8.2V 12.1V
14.1V 13.9V 15.0V
9.1V 9.1V 0.0V

14.7V 12.7V

6.4V 6.4V
DCV 100k:
"of reading + of range"
8ppm + 7pm
4.5PV
8ppm + 7ppm
4.5PV
8ppm + 7ppm
6PV
10k: 100k: 1M:
1ppm 10 ppm 0.01%
10ppm 100 ppm 0.1%
5 1 0.2
110 dB 90dB 70dB

60dB, ±2dB 60dB, ±2dB
12
”0.2
1
0.2
140dB 120dB 80dB
Ocomp
4W -
Kelvin
12.1V
12.7V
0.0V


1M:
"of reading"
8ppm
8ppm
8ppm
10M: 100M:
0.1% 1%
1% 10%
<0.2


Rev A 9/14/07