Fluke 8505A - Source Impedance; Normal Mode; Common Mode

8505A
Table 1-3. Specifications
(cont)
DC RATIO
Accuracy
EXTERNAL
REFERENCE VOLTAGE’
ACCURACY’
±20V to
±4QV ±(A + B + 0.001%)
±Vmin
to
±20V ±(A + B
+
(0.02%
/
|Vxref
D)
'Maximum
External
Reference Voltage
=
±40V between External Reference HI and LO terminals,
providing
neither
terminal is greater
than ±20V relative to the Sense LO or Ohms Guard
2
terminals.
Operating Characteristics
INPUT
IMPEDANCE External Reference HI or LO >10,000 MQ
relative
to
Ohms Guard
2
or
Sense LO.
BIAS
CURRENT
External Reference HI
or LO
relative
to
Ohms Guard
2
or Sense LO <5
nA.
SOURCE
IMPEDANCE
Resistive Unbalance (External
Reference HI to LO)
<4 kfl
Total
Resistance to
Sense LO
from either
External
Reference HI or LO <20
kQ.
MAXIMUM OVERLOAD
VOLTAGE
... ±180V dc
or
peak ac (relative to
Ohms
Guard
2
orSense LO). ±360V
dc
or peak ac (External Reference HI to LO).
NOISE
REJECTION
INPUT
TERMINALS
NORMAL MODE COMMON
MODE
Sense
Same as dc volts
Same
as dc
volts
External
line frequency and
line frequency and
Reference 2x line
frequency 2x
line frequency
>100
dB >75
dB
RESPONSE TIME
Analog Settling
Time
FILTER MODE
FILTER
COMMAND
TO 0.01%
OF
STEP
CHANGE
TO 0.001%
OF
STEP CHANGE
Bypassed
FI
2 ms 20
ms
Fast
F0
or
F3
40
ms
50 ms
Slow
F or F2
400 ms 500
ms
NOTES: (DC
Ratio)
'A
-
10V dc
range accuracy for the appropriate
period of time.
B
Input
signal
function and range accuracy for the appropriate period of
time.
Vdiin Minimum
allowable External Reference
Voltage
=
±0.
0001V,
or V.nput /10
9
(whichever is
greater).
lV/r..f| Absolute
value of the
External Reference Voltage
Ohms Guard
is available through the rear input.
1-5