Fluke 1623 Fluke 1623 and 1625 Geo Earth Ground Testers Datasheet - Page 4

RA 4-pole selective ground resistance measurement with current clamp (RA Switch position RA 4-pole Resolution 0.001 7 to 10 7 Measuring range 0.001 7 to 19.99 k7 Intrinsic error ± (7 % rdg + 3 d) ) Operating error ± (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 (RS) Auxiliary earth electrode resistance (RH) Monitoring of RS, and RH with error indicator Automatic range selection Max. 100 k7 Max. 100 k7 Measurement is not performed if the current through the current clamp is too low Stakeless ground loop measurement ( ) Switch position RA 4-pole Resolution 0.001 7 to 0.1 7 Measuring range 0.001 7 to 199.9 7 Intrinsic error ± (7 % rdg + 3 d) Operating error ± (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 (IEXT) Max. IEXT = 10 A (ac) (RA < 20 7) Max. IEXT = 2 A (ac) (RA > 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. 4 Fluke Corporation 1623 and 1625 GEO Earth Ground Testers