Fluke 1623 - Page 4

4 Fluke Corporation 1623 and 1625 GEO Earth Ground Testers
R
A
4-pole selective ground resistance measurement with current clamp (R
A
)
Switch position Resolution Measuring range Intrinsic error Operating error
R
A
4-pole
0.001 7 to 10 7 0.001 7 to 19.99 k7 ± (7 % rdg + 3 d) ± (10 % rdg + 5 d)
Measuring principle: Current/voltage measurement (with external current clamp)
Measuring voltage Vm = 48 V ac
Short-circuit current > 50 mA
Measuring frequency 128 Hz (125 Hz on request)
Probe resistance (R
S
) Max. 100 k7
Auxiliary earth electrode resistance (R
H
) Max. 100 k7
Monitoring of R
S
, and R
H
with error indicator
Automatic range selection
Measurement is not performed if the current through the current clamp is too low
Stakeless ground loop measurement ( )
Switch position Resolution Measuring range Intrinsic error Operating error
R
A
4-pole 0.001 7 to 0.1 7 0.001 7 to 199.9 7 ± (7 % rdg + 3 d) ± (10 % rdg + 5 d)
Measuring principle: Stakeless measurement of resistance in closed loops using two current transformers
Measuring voltage Vm = 48 V ac (primary)
Measuring frequency 128 Hz (125 Hz on request)
Noise current (I
EXT
) Max. I
EXT
= 10 A (ac) (R
A
< 20 7)
Max. I
EXT
= 2 A (ac) (R
A
> 20 7)
Automatic range selection
The information regarding stakeless ground loop measurements is only valid when used in conjunction with the recommended current clamps at the minimum
distance specified.