HT instruments M71 - Manual (Page 21)

M71
EN – 20
6. TECHNICAL SPECIFICATIONS
6.1. TECHNICAL FEATURES
Accuracy is indicated 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
Accuracy
Disturbance ≤ 3Vrms
3Vrms
AUTO mode triggered
0.01 ÷ 19.99Ω 0.01 Ω
±(2%rdg + 3dgt) ±(4%rdg + 10dgt)
20.0 ÷ 199.9Ω 0.1 Ω
200 ÷ 1999Ω 1 Ω
2.00 ÷ 19.99kΩ 0.01k Ω
20.0 ÷ 49.9kΩ 0.1k Ω ±(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:
¾
If R
A
≤ 10Ω Æ Rc, Rp ≤ 1kΩ
¾ If 10 Ω < R
A
≤ 500Ω Æ Rc, Rp ≤ 100 * R
A
¾ If R
A
> 500 Ω Æ Rc, Rp ≤ 50kΩ
Disturbance Voltage measurement
Range (V) Resolution (V) Accuracy
0.0 ÷ 99.9 0.1
±(2%rdg + 2dgt)
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