Datasheet
METRISO XTRA
High-Precision
Insulation, Low Resistance and Voltage Measurement Instrument
2 GMC-I Messtechnik GmbH
Polarization Index
A polarization index test is recommended for electrical machines
with coil modules (generator and motor coils). This procedure
involves expanded testing of insulation resistance. A reduced
insulation resistance is an indication of humidity absorption and
fouling.
To this end, the DC measuring voltage of the METRISO XTRA is
applied to the insulation for a duration of 10 minutes. The respec-
tive measured value is read after one and after ten minutes. If the
insulation is faultless, the value measured after ten minutes is
higher than the value measured after one minute. The relationship
between the two measurement values is the polarization index.
Charged material within the insulation is aligned due to the appli-
cation of DC measuring voltage over a long period of time, result-
ing in polarization. The polarization index indicates whether or not
the charged material contained in the insulation can still be
moved, thus allowing for polarization. This, in turn, is an indication
of the condition of the insulation. The more the charged material
can be moved, the better is the state of the insulation.
Discharging of Capacitive DUTs
Capacitive devices under test such as cables and coils which may
charge up to test voltage are discharged via the test instrument
while the voltage decrease can be monitored at the display.
Data Management and Report Generation
A complete distribution structure with customer, building and dis-
tributor data can be set up in the test instrument.
This structure allows for the assignment of measurements to the
distributors of different buildings and customers.
Intelligent filter
Measurement-dependent and precise activation for the measure-
ment of very high resistances with:
• beating, i. e. compensation of 16
2
/
3
Hz and 50 Hz interferences
• attenuation of capacitive influences from power cables, etc.
• suppression of electric field influences
Characteristic Values
METRISO XTRA
1)
the indicated accuracy is only achieved with the shielded high-resistance
measuring cable KS-C (article no. Z541F)“ as optional accessory.
2)
does not conform to DIN EN 61557-2
3)
display range up to 1.2 kV
4)
up to 5
Breakdown Voltage (Uramp)
Polarization Index (PI), Absorption Ratio (DAR)
PI and DAR are calculated values. The specifications of the insulation measurement
apply.
Reference Conditions
Reference
temperature + 23 C 3K
Relative humidity 40 ... 75%
Measured quantity
frequency
45 Hz ... 65 Hz
Measured quantity
waveshape Sine, deviation between TRMS and
rectified value < 1%
Battery voltage 9.5 V 0.1 V
Test resistor 10 M1%
Meas.
Qty.
U
iSO
Range Measuring Range
Reso-
lution
Open-Circuit
Voltage
U
0max
Test Current Intrinsic Uncertainty Measuring Uncertainty Overload Capacity
R
ISO
50 V
100 V
250 V / 500 V
1000 V
100 k 10 k ... 99.9 k 0.1 k
50 V /100 V:
1.25 U
ISO
250 V /
500 V /
1000 V:
1.1 U
ISO
I
N
= 1 mA
I
K
5 mA
(5% rdg. + 3 d) (7% rdg. + 3 d)
1000 V AC/DC
TRMS
1 M 100 k ... 999 k 1 k
10 M 1.00 M ... 9.99 M 10 k
100 M 10.0 M ... 99,9 M 100 k
1 G 100 M ... 999 M 1 M
10 G 1.00 G ... 9.99 G 10 M
100 G 10,0 G ... 99.9 G 100 M (8% rdg. + 3 d)
1)
(10% rdg. + 3 d)
1)
1 T 100 G ... 999 G 1 G (25% rdg. + 5 d)
1)
(50% rdg. + 20 d)
1) 2)
U
AC/DC
100 V 10.0 V ... 99.9 V 0.1 V
——(2.5% rdg. + 3 d) (5% rdg. + 3 d)
1000 V AC/DC
TRMS
3)
1000 V 100 V ... 999 V 1 V
R
LO
10 0.17 ... 9.99
0.01
4 V < U
0
< 6 V
200 mA I
I
260 mA
4)
(2.5% rdg. + 3 d) (5% rdg. + 3 d)
1000 V AC/DC
TRMS
R
Display range as of
01.0
100 10.0 ... 99.9 0.1
U
0
max. 15 V
1 mA I
I 1.3 mA
(2.5% rdg. + 3 d) (5% rdg. + 3 d)
1000 V AC/DC
TRMS
1 k 100 ... 999 1
10 k 1.00 ... 9.99 k 10
Parameter Range Intrinsic
Uncertainty
Measuring
Uncertainty
Voltage range 100 1000 V
(10% rdg. + 8 d)
(
15% rdg. + 10 d)
Rise time 5 30 s — —
Measuring duration 1 120 s / auto / per-
manent measurement
——
t1 t2 Limit
PI 01:00 min 10:00 min > 4.0 min / > 3.0 min / > 2.0 min / > 1.5 min
/ > 1.1 min / > 1.0 min
DAR 00:30 min 01:00 min > 1.60 min / > 1.25 min