MI 3290 Earth Analyser
Technical specifications
138
15.7.2 Flex Clamps Meter RMS
Measurement principle: ............................... Current measurement (RMS)
Current RMS
Measuring range
Resolution
Uncertainty (* See note)
If1, If2, If3, If4
10 mA … 99,9 mA
0,1 mA
(8 % of r 3 digits)
100 mA … 999 mA
1 mA
1,00 A … 9,99 A
0,01 A
10,0 A … 49,9 A
0,1 A
Test mode ...................................................... continuous
Input impedance (F1 –F4).............................. 10 k
Nominal frequency ........................................ 45 Hz … 1,5 kHz
Measuring refresh rate .................................. typical 2 s
Measurement Clamp type ............................ A1487
Automatic range selection ............................ yes
Automatic clamp recognition ....................... yes [F1, F2, F3, F4]
* Note:
Current RMS measurement ranges and uncertainty for one turn except for the
measurement range of 10 mA … 99,9 mA, which must be at least 3 turns.
Do not measure close to other current-carrying conductors if possible. An external magnetic field
can cause an additional measurement uncertainty.
Clamps
External magnetic field
Additional uncertainty
Flex clamp (A1487)
5 A/m
(15 % of reading)
It is very important that the conductor should be at the centre and perpendicular to the
measuring head.
Full-scale value of the Flex current (If1, If2, If3, If4) depends on the number of turns of the Flex
clamp (1, 2, 3, 4, 5, 6) and is defined according to the following equation:
turns
of
number
9
,
49
A
If
FS
0.7
0.8
0.9
1
1.1
1.2
1.3
10
100
1000
10000
I
[A
]
f [Hz]
Clamp current vs Frequency [1,0 A
rms
]
Flex clamp (A1487)
Iron clamp (A1018)
