Current measurement

range

±1 mA

resolution (current display when measuring)

1 pA

resolution (recorded data)

0.1 pA

accuracy

0,5% of the measured value ±1 pA after 1 hour warming up

impedance

10 k

protection

up to 100 mA respectively 1kV for 50 ms

noise suppression 

up to 10 µA eff at 50 / 60 Hz mains frequency

filtering (current display when measuring)

mean value in 1 s intervals

filtering (recorded data)

mean value in intervals increasing proportionally with the time from the voltage source switching moment

 

Voltage source

voltage range when switched on

+30 ...+2000 V

maximum current sourcing when switched on

<+5 mA

impedance when switched on

<20 k

impedance when switched to zero

<0.2

current limiting when switching cap. loads

<±100 mA for 20 ms

 

Capacitance measurement

the load capacitance is indirectly measured by computing the ratio charge to voltage when the voltagesource is switched off for measuring of the depolarisation current. However, the current measurement is not impaired by a load capacitance depassing the range listed below.

load capacitance measuring range at 2 kV source voltage

25 nF

accuracy at 2 kV source voltage

±2 % ±5 pF

load capacitance measuring range at 1 kV source voltage

50 nF

accuracy at 1 kV source voltage

±2 % ±10 pF

load capacitance measuring range at 500 V source voltage

100 nF

accuracy at 500 V source voltage 

±2 % ±20 pF

load capacitance measuring range at 100 V source voltage

500 nF

accuracy at 100 V source voltage

±2 % ±100 pF

 

Computer

display

15" TFT, 262'144 colours, resolution 1024x786 pixels

processor

Intel Pentium III 705 MHz

memory

SDRAM 128 MB (up to 256 MB optional)

hard disk

10 GB

standard interfaces

CD-ROM, 3½" Floppy, 2x PCMCIA, parallel and serial ports, Ethernet

options

additional serial ports, Audio in/out, external Monitor out

 

Software

operation system

windows 98 SE

measuring and control program

installed ready to use, outputs for each measurement one file with polarisation data, one file with depolarisation data and one file with general measurement descriptions

standard evaluation software

installed ready to use, easy to use, extensive possibilities to postprocess, display, print and export the measured data, computation of the complex capacitance in function of frequency, computation of a lumped equivalent circuit of the measured insulation, computation of recovery voltages and the derived "polarisation spectrum", computation of polarisation indexes and of insulation resistances according to all known standards and definitions

advanced evaluation software

quality assessment of oil-paper insulation systems quantitative determination of moisture content in pressboard and of oil conductivity for power transformers