HT GroundTest M71 - 6 Technical Specifications; Technical Features

GroundTest M71
EN – 20
6. TECHNICAL SPECIFICATIONS
6.1. TECHNICAL FEATURES
Accuracy is calculated as [% rdg + (dgt number) * resolution] at 23°C ± 5°C,< 80%HR
CAUTION
Under modes EARTH-2W and EARTH-3W the instrument displays the
symbol of warning whenever:
 It is working under critical conditions, such as in the presence of input
voltages
 It cannot grant the uncertainty of measurement lower than 30% of
reading, according to IEC/EN61557-1
Earth Resistance measurement
Range Resolution
A
ccurac
y
Disturbance  3Vrms
3Vrms<Disturbance<6Vrms
AUTO mode triggered
0.01  19.99 0.01
(2%rdg + 3dgt) (4%rdg + 10dgt)
20.0  199.9 0.1
200  1999 1
2.00  19.99k 0.01k
20.0  49.9k 0.1k (3rdg + 3dgt) (6%rdg + 10dgt)
Measurement frequency 110Hz  1Hz
Test current 12mA~
Open circuit voltage 25Vrms
Resistance values of the voltmetric (Rp) and ampermetric probes (Rc) always meet the following conditions:
 If R
A
 10  Rc, Rp  1k
 If 10 < R
A
 500  Rc, Rp  100 * R
A
 If R
A
> 500  Rc, Rp  50k
Disturbance Voltage measurement
Range (V) Resolution (V) Accuracy
0.0  99.9
0.1
(2%rdg + 2dgt)
100  299
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