Ac signal cross talk into an ac voltage channel, Ac signal cross talk into an ohms channel, Ac signal cross talk into a frequency channel – Fluke 2625A User Manual
Page 178
2620A/2625A
Users Manual
D-2
AC Signal Cross Talk Into an AC Voltage Channel
ACV Error Ratio =
VACrms error
VACrms crosstalk
Frequency crosstalk
(
)
(
)
(
)
×
Range
Ratio (worst case)
Ratio (typical)
×
v
Hz
Ч
Ч
v
Hz
Ч
Ч
v
Hz
Ч
Ч
v
Hz
×
30.000 V
1.2
×
10
-6
v
Hz
Ч
2.6
Ч
10
-7
v
Hz
Ч
150.00/300.00 1.2
Ч
10
-5
v
Hz
Ч
3.4
Ч
10
-6
v
Hz
×
For example, to find the typical effect of a 60 Hz, 220V ac signal on another channel for
the 300 mV range, you would calculate: 220 X 60 X 1.4 X 10
-8
= 0.18 mV.
AC Signal Cross Talk Into an Ohms Channel
AC Frequency = 50, 60 Hz, ±0.1%
OHMS Error Ratio
1
=
Ohms error
VACrms crosstalk
(
)
(
)
Range
Ratio (worst case)
Ratio (typical)
×
Ohms
Vrms
3.0000 k
e
2.4
×
Vrms
×
Vrms
30.000k
e 3.1
×
10
-
4
kOhms
Vrms
8.4
×
10
-5
kOhms
Vrms
300.00 k
e
5.6
×
10
-3
kOhms
Vrms
3.7
×
10
-3
kOhms
Vrms
3.0000 M
e
3.8
×
10
-4
MOhms
Vrms
3.8
×
10
-5
MOhms
Vrms
10.000 M
e
1.4
×
10
-3
MOhms
Vrms
4.3
×
MOhms
Vrms
For example, to find the typical effect of a 60 Hz, 100V ac signal on another channel for
the 30 k
Ω
range, you would calculate: 100 X 8.4 X 10-5 = 0.008 k
Ω
.
AC Signal Cross Talk Into a Frequency Channel
Frequency measurements are unaffected by cross talk as long as the voltage-frequency
product is kept below the following limits:
Worst Case
Typical
V x Hz Product Limit
3.7
×
10
4
(V
×
Hz)
1.0
×
10
6
(V
×
Hz)
These values assume no more than 1000 pf of capacitance between either end of the resistor (HI and LOW ) and
earth ground.