Operation Manual
64 GMC-I Messtechnik GmbH
11 Appendix
11.1 Glossary
11.2 Minimum Display Values in Consideration of
Measuring Error
Table for determining minimal display values for insulation resis-
tance in consideration of the instrument’s measuring error:
Abbreviation
Meaning
DAR
Absorption Ratio: Ratio between insulation resistance values measured after 30 and 60 seconds
DD Dielectric Discharge
ΔR
Lim
Maximum allowable statistical deviation from the measured mean value
Δt/250V Dwell Time per Step
PI Polarization Index:
Ratio between insulation resistance values measured after 1 and 10 minutes
I
MAX
Max. allowable current before high-voltage is switched off
I
T
Interrupting current for high-voltage test
R
ins
Insulation Resistance
Limit R
ins
Limit value for insulation resistance
T
R
Rise time: time during which test voltage climbs to U
AC.MAX.
T
D
Test duration at maximum test voltage U
AC.MAX.
(not including rise time TR)
U
AC.MAX.
Maximum test voltage for high-voltage testing
U
brk
Breakdown Voltage
U
ins
Test Vo lt ag e
U
(ins) end
Ramp Function Upper Limit
U
meas
Measuring Voltage
U
nom
Nominal Test Voltage
U
T
Voltage value before exceeding interrupting current during high-voltage testing
U
STEP
Test voltage as ramp sequence
U
test
Test Vo lt ag e
U
var
Variable Test Voltage
Limit Value Minimum Display
Value
Limit Value Minimum Display
Value
0.10 MΩ 0.12 MΩ 100 MΩ 118 MΩ
0.20 MΩ 0.23 MΩ 200 MΩ 228 MΩ
0.50 MΩ 0.56 MΩ 500 MΩ 558 MΩ
1.00 MΩ 1.18 MΩ 1.00 GΩ 1.18 GΩ
2.00 MΩ 2.28 MΩ 2.00 GΩ 2.28 GΩ
5.00 MΩ 5.58 MΩ 5.00 GΩ 5.58 GΩ
10.0 MΩ 11.8 MΩ 10.0 GΩ 11.8 GΩ
20.0 MΩ 22.8 MΩ
50.0 MΩ 55.8 MΩ