Keithley 3700 Series User Manual

Section 8: Theory of operation Series 3700A System Switch/Multimeter Reference Manual
8-16 3700AS-901-01 Rev. D/June 2018
dmm.opendetector open voltage
With dmm.opendetector = dmm.ON, a separate -1.5 A I
OPENLEAD
SHI and a separate SLO current
source will pulse on and off before the start of each measurement while I
SOUR
remains enabled. The
A/D will monitor SHI for 2 ms, then switch to SLO for an additional 2 ms. During either phase, if the
input voltage exceeds the above table, the A/D will stop in less than 100 µs and return an overflow
reading. If there are no open leads detected during the I
OPENLEAD
phase, the I
OPENLEAD
is disabled and
standard 4-wire is enabled.
V
MEAS
with open input:
If Sense HI is disconnected, V
MEAS
will droop less than –1V, causing an A/D overflow.
V
MEAS
with valid connections:
For valid connections, INPUT Sense HI, V
MEAS
, will dip during the 4 ms I
OPENLEAD
phase. The amount
of the voltage dip is the sum of I
OPENLEAD
and the range I
SOUR
and R
DUT
load. For example, if
measuring a 100 kΩon the 100 kΩrange, the V
MEAS
across the 100 kΩ will be 0.85 V (10 A to
1.5 µA) × 100 KΩduring I
OPENLEAD
and 1 V during measurement phase.
The tables below note timing with dmm.opendetector = dmm.ON.
Range
SHI and SLO
IOPENLEAD
phase (ms)
1
SHI settling
time (ms)
Line frequency
(Hz)
SHI measurement time
(ms)
1-10 kΩ
4.0
0.5
60
min
max
0.0083
250
50
0.010
240
100 kΩ
4.0
2.0
60
0.0083
250
50
0.010
240
1 MΩ
4.0
30.0
60
0.0083
250
50
0.010
240
10 MΩ to
100 MΩ
4.0
5.0
1
60
0.0083
250
Range
Internal
DMM comm
(ms)
SLO
settling
time (ms)
SLO
measurement
time (ms)
Internal
DMM comm
1 kΩ to
10 kΩ
0.06
0.5
min
max
0.06
0.0083
250
0.010
240
100 kΩ
0.06
1.0
0.0083
250
0.06
0.010
240
1 MΩ
0.06
1.0
0.0083
250
0.06
0.010
240

Keithley 3700 Series Specifications

General

Model	Keithley 3700 Series
Category	Multimeter
Number of Channels	Up to 576 channels
Measurement Functions	DC Voltage, AC Voltage, DC Current, AC Current, Resistance, Frequency, Temperature, Capacitance
DC Voltage Range	300 V
AC Voltage Range	300 V
Frequency Range	3 Hz to 500 kHz
Temperature Range	Varies with sensor type
Temperature (Thermocouple) Types	J, K, T, E, R, S, B, N
Capacitance Range	1 pF to 100 μF
Connectivity	LAN, USB, GPIB
Interface	GPIB, Ethernet, USB
Power Supply	100 V to 240 V, 50 Hz to 60 Hz
Dimensions	8.4 in x 16.8 in x 17.5 in