Selective (Flex Clamps 1 - 4); Test Mode; Test Frequency; Limit Range (Ze) - METREL MI 3290 Instruction Manual

MI 3290 Earth Analyser

15.1.6 Selective (Flex Clamps 1 - 4)

Measurement principle: ............................... Voltage / Current (external Flex Clamp) measurement
Total Earth

Test frequency

Impedance
55 Hz ... 329 Hz
Ztot
659 Hz ... 2,63 kHz
3,29 kHz ... 6,59 kHz
Test mode ...................................................... single or sweep
Open-terminal test voltage ........................... 40 Vac
Test frequency ............................................... 55 Hz, 82 Hz, 94 Hz, 105 Hz, 111 Hz, 128 Hz, 164 Hz, 329 Hz,
....................................................................... 659 Hz, 1.31 kHz, 1.50 kHz, 2.63 kHz, 3.29 kHz, 6.59 kHz
Short-circuit test current ............................... > 220 mA @ 164 Hz, 40 Vac
Limit range (Ztot) .......................................... 0,1  ... 5 k (OFF)
Test voltage shape ......................................... sine wave
Ztot definition ................................................ Impedance value Z(f)
Measuring time ............................................. see Table 15.2
Automatic test of probe resistance ............... yes
Automatic connection test ........................... yes [H, S, ES, E]
Automatic range selection ............................ yes
Automatic test of voltage noise .................... yes
Low clamp current indication ........................ yes [If1, If2, If3, If4]
Automatic clamp recognition ....................... yes [F1, F2, F3, F4]
* Notes:

Uncertainty depends of the resistance of probes and auxiliary earth electrodes (See 15.9 Influence
of the auxiliary electrodes).


1 m resolution

Rc < 300 and test frequency ≤ 329 Hz.
Typical Measuring time
Test frequency
55 Hz
329 Hz
1.50 kHz
6.59 kHz
15.0 kHz
sweep
Table 15.2: Typical measuring times for different measurements
Measuring range
0,010  ... 1,999 
2,00  ... 19,99 
20,0  ... 199,9 
200  ... 999 
1,000 k ... 1,999 k
2,00 k ... 19,99 k
0,00  ... 19,99 
20,0  ... 199,9 
200  ... 999 
1,000 k ... 1,999 k
0,00  ... 19,99 
20,0  ... 199,9 
only for
Measurement
2 – pole 3 – pole 4 – pole Selective (Iron Clamp)
17 s 32 s 45 s
8 s 11 s 15 s
6 s 10 s 12 s
6 s 9 s 12 s
6 s 9 s 11 s
1:14 s 2:17 s 3:20 s
Resolution
0,001 
0,01 
0,1 
1 
0,001 k
0,01 k
0,01 
0,1 
1 
0,001 k
0,01 
0,1 
resistance of auxiliary
57 s
19 s
15 s
/
/
3:35 s
131
Technical specifications
Uncertainty (* See notes)
(8 % of reading + 3 digits)
(8 % of reading + 3 digits)
(10 % of reading + 3 digits)
earth electrodes
Selective (Flex Clamp 1-4)
1:13 s
23 s
18 s
18 s
/
5:30 s (1 x Flex Clamp)