Influence Of Interference Current On The Result Of The Earth Resistance Measurement For Two-Clamp Method (2C); Influence Of The Relation Of The Resistance Measured With Clamp For The Multiple Earthing Branch To The Resultant Resistance (R E 3P+C); Additional Uncertainties In Accordance With Iec 61557-4 (2P); Additional Uncertainties In Accordance With Iec 61557-5 (R 3P, R 4P, R 3P+C) - Sonel MRU-200 User Manual

10.2.7 Influence of interference current on the result of the earth resistance
measurement for two-clamp method (2C)
The MRU-200 / MRU-200-GPS meter may perform a measurement, if the value of the interfer-
ence current does not exceed 3 A RMS and the frequency complies with the value set in the MENU.
20.0...149.9 Ω
If the interference current exceeds 3 A the possibility of measurement is blocked.
10.2.8 Influence of the relation of the resistance measured with clamp for
the multiple earthing branch to the resultant resistance (R
[Ω] is the value of the resistance measured with clamps for the branch displayed by the device,
R
C
[Ω] is the value of the resultant multiple earth resistance.
and R
W

10.2.9 Additional uncertainties in accordance with IEC 61557-4 (2P)

Influencing factor
Location
Power supply voltage
Temperature
10.2.10 Additional uncertainties in accordance with IEC 61557-5 (R
R 4P, R
E
Influencing factor
Location
Power supply voltage
Temperature
Serial interference voltage
Resistance of electrodes and
auxiliary earth electrodes
56
R
E
0.00...4.99 Ω
5.00...19.9 Ω
R
C
≤99.9 Ω
>99.9 Ω
3P+C)
E
MRU-200 ● MRU-200-GPS – USER MANUAL
Uncertainty [Ω]
within the range of the accuracy

   R 
2
3
5 ( 10
E
    R 
2
2
6 ( 10
E
Uncertainty [Ω]

  
3
3 ( 10
   
2
6 ( 10
Symbol Additional uncertainty
E
1
E
0% (BAT not displayed)
2
R≤3,999Ω
R>3,999Ω and
E <1kΩ
3
R≥1kΩ
Symbol
E
1
E
2
R≤3,999 Ω
R>3,999 Ω and
E <1 kΩ
3
R≥1 kΩ
In accordance with formula In 10.2.1
E
4
(U
z
In accordance with the formula in
E
5
3
I )
zakl
3
I )
zakl
R
C
)
2
R
w
R
C
)
2
R
w
0%
±0,3digits/°C
±0,2digits/°C
±0,07%/°C
±0,2 digits/°C
Additional uncertainty
0%
0% (BAT not displayed)
±0,3 digits/°C
±0,2 digits/°C
±0,07%/°C
±0,2 digits/°C
=3 V 50/60/400/16 2/3 Hz)
10.2.3
3P+C)
E
3P,
E