Fluke 1535 - Principle of Measurement and Resistance

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Users Manual
32
Principle of Measurement and Resistance
The Tester uses these formulas to measure insulation parameters and display
the results:
Table 15. Operating Uncertainties per EN 61557
Parameter Specification Typical
Max
[1]
Intrinsic
uncertainty
IEC 61557-2
A, Reference conditions
1.63 % 3.68 %
Position
IEC 61557-2
E1, Reference Conditions ±90 °
2.29 % 5.00 %
Supply
Voltage
IEC 61557-2
E2, At low battery voltage stated
by manufacture
2.80 % 6.09 %
Temperature
IEC 61557-2
E3, 0 °C and 35 °C
3.36 % 9.83 %
Operating
Uncertainty
IEC 61557-2
B, ≤30 %
7.30 % 18.17 %
[1] Confidence level: 95 %
Ohm’s Law
Capacitance
(Charge)
PI
(Polarization Index)
DAR
(Dielectric Absorption
Ratio)
I
V
R =
V
Q
C 
min1
min10
R
R
PI =
s
R
R
DAR
30
min1

s
R
R
DAR
15
min1

[CN]