XT2640 Operating Manual
13 July 2016
Page 172 of 187
28.3.2.1
PRIMARY
CURRENT
MEASUREMENT
ACCURACY
TABLE
Add relevant errors from the table below for the maximum error in primary current measurements (e.g. DC, AC, AC+DC, Rectified,
Peak, Valley, Peak‐Valley).
MAXIMUM
SCALING
ERRORS
Apply to all results as shown below as a percentage of the reading
If signal contains significant levels at multiple frequencies, apply to each level & frequency
Specification
Channel
Type
Option
H
Option
D
HI
Range
Option
D
LO
Range
Option
X
HI
Range
Option
X
LO
Range
Base
Scaling
Error
Apply to all results
A or L
0.03%
S or W
0.1% (0.2% if 2ms LF/PERIOD)
Frequency
Dependent
Scaling
Error
Apply to all results
other than DC or
MAINS
LF or VLF
S, A or L
0.01%
W
0.05%
AVIONICS
A or L
0.002%
S or W
None
<10kHz
S, A or L
F*0.003%
W
F*0.0015%
10k‐40kHz
S, A or L
0.03%+(F‐10)*0.007%
W
F*0.0015%
40k‐100kHz
S, A or L
0.24%+(F‐40)*0.02%
W
0.06%+(F‐40)*0.003%
0.06%+(F‐40)*0.004%
100k‐1MHz
S, A or L
Typically (F/1250)
2
*100%
W
0.24%+(F‐100)*0.012%
0.3%+(F‐100)*0.015%
>1MHz
W
Typically (F/5000)
2
*100%
Typically (F/3000)
2
*100%
Self
‐
Heating
Scaling
Error
Apply to all results (only
significant at higher currents)
3 minute nominal time constant
All
0.00015%*A
AC+DC2
0.0002%*A
AC+DC2
None
Temperature
Scaling
Error
Apply to all results if outside of
±5C from calibration temperature
All
0.005% per C outside of ±5C from calibration temperature
Bandwidth
Limit
Scaling
Error
Apply if using USER bandwidth
setting
All
10%*(F/F
BW
)
2
, unspecified above 0.3*F
BW
MAXIMUM
FLOOR
ERRORS
Apply to all results as shown below in Amps (generally only significant at low input levels)
Specification
Channel
Type
Option
H
Option
D
HI
Range
Option
D
LO
Range
Option
X
HI
Range
Option
X
LO
Range
Base
Floor
Error
Apply to all results
A or L
56µA
38µA
250nA
6µV
150nV
S or W
225µA
150µA
1µA
23µV
600nV
DC
Floor
Error
Apply to DC and RECTIFIED
results
Apply to AC+DC results after
multiplying by A
DC
/A
AC+DC
A or L
0.23mA
0.15mA
1µA
40µV
5µV
S
0.45mA
0.3mA
2µA
80µV
6µV
W
0.68mA
0.45mA
3µA
120µV
8µV
AC
Floor
Error
Apply to AC,
AC+DC, and
RECTIFIED
results
MAINS, LF, VLF &
F
BW
≤10kHz
S, A or L
3.3µA/A
RDG
1.5µA/A
RDG
90pA/A
RDG
35nV/A
RDG
20pV/A
RDG
W
5µA/A
RDG
2.5µA/A
RDG
125pA/A
RDG
50nV/A
RDG
50pV/A
RDG
AVIONICS &
F
BW
≤50kHz
S, A or L
33µA/A
RDG
15µA/A
RDG
0.9nA/A
RDG
350nV/A
RDG
200pV/A
RDG
W
50µA/A
RDG
25µA/A
RDG
1.25nA/A
RDG
500nV/A
RDG
500pV/A
RDG
Otherwise
S, A or L
330µA/A
RDG
150µA/A
RDG
9nA/A
RDG
3.5µV/A
RDG
2nV/A
RDG
W
500µA/A
RDG
250µA/A
RDG
12.5nA/A
RDG
5µV/A
RDG
5nV/A
RDG
Peak
Floor
Error
Apply to PK,
VLY and PK‐
VLY results
MAINS, LF, VLF &
F
BW
≤10kHz
S, A or L
8mA
5mA
40µA
0.75mV
25µV
W
10mA
6.5mA
50µA
0.9mV
30µV
AVIONICS &
F
BW
≤50kHz
S, A or L
25mA
17mA
125µA
2.5mV
65µV
W
30mA
20mA
150µA
3mV
80µV
Otherwise
S, A or L
75mA
50mA
400µA
7.5mV
200µV
W
90mA
60mA
500µA
10mV
250µV
Common
Mode
Error
Apply to all results
Apply using voltage on A LO
terminal relative to chassis
ground. Error has 90° phase shift
to common‐mode voltage
All
500pA per V.Hz
(5.75µA@230V/50Hz)
400pA per V.Hz
(4.6µA@230V/50Hz)
20pA per V.Hz
(0.23µA@230V/50Hz)
15nV per V.Hz
(0.172mV@230V/50Hz)
0.5nV per V.Hz
(5.75µV@230V/50Hz)
Adjacent
Channel
Error
Apply to all results
Apply using adjacent channel A LO
or V LO terminal voltage relative
to chassis ground. Error has 90°
phase shift to adjacent channel
voltage
All
150pA per V.Hz
(1.725µA@230V/50Hz)
120pA per V.Hz
(1.38µA@230V/50Hz)
7pA per V.Hz
(80.5nA@230V/50Hz)
7nV per V.Hz
(80.5µV@230V/50Hz)
0.2nV per V.Hz
(2.3µV@230V/50Hz)