A l p ha ­ A M o d ul a r
M e a s u r e m e n t Sy s t e m• Test Interface for Dielectric, Conductivity,Impedance 2, 3 and 4 Electrode Spectroscopyand Gain Phase Measurements for the Alpha­AModular Measurement System• Very wide frequency range: 3 µHz to 40 MHz• Extremely wide impedance range:0.1 mΩ to 100 TΩ, i.e., 18 decades.
• Excellent phase and tan() resolution andaccuracy• Driven shields reduce influence of cable capacity
on the voltage measurement• Connects your own sample cells to the Alpha­Asystem• Recommended for usage with BDS 1200 andNovotherm­HT sample cells (not included)

Novocontrol Technologies
GmbH & Co. KG
Aubachstr. 156410 Montabaur
Germany
Phone: +49 2602 9196690
Fax:+49 2602 91966933
e­mail: novo@novocontrol.de
web: http://www.novocontrol.de

ZG4

ZG4 Test Interface for theNOVOCONTROLZG4 Test Interface
The ZG4 extension test interface forthe Alpha­A modular measurement
system features high quality general
purpose dielectric, conductivity, im­pedance spectroscopy in two,three, and four point modes, andgain phase measurements.
Three and four point techniques areadvantageously used to partly com­pensate electrode­sample interface
polarization or contact impedance
effects. The ZG4 test interface has
the same functionality as the ZG2 in­
terface but two additional differenti­
al voltage measurement channels
for three and four point measure­ments.
The voltage channel input impe­
dance of 1012 Ω|10 pF exceeds thecorresponding values of most com­
peting instruments by several ordersof magnitude, representing a major
improvement in broadband three­and four­point measurements.
In order to reduce the cable capa­
city from the ZG4 voltage inputs tothe voltage electrodes, the two vol­tage inputs support driven shieldtechnology which keeps the potenti­
al of the outer coaxial cable shieldat nearly the same potential as thesensitive inner cable conductor.
The ZG4 has high general purpose
performance but is especially re­commended for dielectric or con­ductive samples with• significant electrode contact im­pedance or electrode sample in­terface polarization like, e.g.
electrolytes;• low impedance samples (below1 Ω) like e.g. strong electrolytes,heavily doped semiconductors,metals, superconductors;• electronic components or net­
works.

ZG4
ZG4 Specifications:
RangesFrequency: 3 µHz ... 40 MHz (13.1 decades)*Impedance: 10­4 .. 1014 Ω (18 decades)
Capacitance: 1 fF ... 10 F (16 decades)
Loss factor tan(δ): 10­5 .. 104
AC signal out:
100 µV .. 3 Vrms
DC bias out:­40 VDC .. +40 VDC, 70 mA max**
Signal generator output impedance: 50 ΩVoltage input: < ± 4.3 Vp dc or ac coupled
Differential Voltage Inputs with Driven Shields
Input impedance: 1012 Ω | 10 pF
Common Mode Rejection:< 10­4 below 100 kHz; < 10­3 dB below 1 MHz
Input Bias Current: < 2.10­12 A
Base Accuracy
Relative Impedance, Relative Capacity,Loss factor tan(δ): < 3.10­5 ***Phase Angle:< 0.002° ***Resolution
Relative Impedance, Relative Capacity,
Loss factor tan(δ): < 10­5Phase Angle:< 0.0006°
User Calibrations:load, short, open, internal self calibration anddiagnostics* in combination with the Alpha­A mainframe type AT** requires dc bias option B of the Alpha­A mainframe*** for details refer to specification charts

The ZG4 can be combined with any type ofsample cells for materials measurements in
two/three/four wire modes via its BNC connec­
tors. A sample cell is not included. For two­electrode configurations, the passive BDS 1200
sample cell is recommended. The external in­
terface design allows to locate the ZG4 close
to the sample in order to minimize cable effects
due to, e.g., inductance and subsonic noise
which may influence the results in the the highand low frequency ranges, respectively.
System requirements• Impedance analyzer mainframe Alpha­A