POT/GAL 15V 10A and 30V 2A

Test Interfaces for Electrochemical Impedance, Dielectric, Conductivity, 2, 3 and 4 Electrode Spectroscopy and Gain Phase Measurements with Potentiostat, Galvanostat for  Alpha-A Modular Measurement System

The POT/GAL 15V 10A and 30V 2A extension test interfaces for the Alpha-A modular measurement system feature high quality electrochemical impedance spectroscopy EIS, conductivity and dielectric spectroscopy with 2, 3 and 4 electrodes and gain phase measurements.

For electrochemical applications, fast potentiostat and galvanostat control loops for defined dc voltage and current cell polarization control are included. These  can be superimposed by an ac signal for EIS.

Like all other Alpha-A test interfaces, the POT/GAL interfaces feature high overall performance like, e.g., broad bandwidth, ultra-wide impedance range and highest accuracy which now becomes available for EIS applications, too, The POT/GAL interfaces are thus a major improvement in EIS instrumentation.

In addition to EIS, typical electrochemical experiments like cyclic voltammetry and DC measurements in the time domain are supported.

The POT/GAL interfaces are not only optimized for low impedance samples with strong electrode sample interface polarization effects but  accurately measure high impedance insulators, too. The interfaces are particularly recommended for the characterization of

• electrochemical cell reactions, metal-electrolyte interfaces, ion conductors, conductive liquids for both low and high impedance samples up to 10¹³ Ω;
• general purpose low impedance samples or electronic components at high currents.

The POT/GAL interfaces include high voltage and current output signal amplitudes up to ±15 Vp, ±10 Ap or ±30 Vp, ±2 Ap both for dc and ac signals. 

For applications which do not require potentiostat or galvanostat control, a direct voltage mode is available. In this mode, the POT/GAL interfaces can be used for general purpose dielectric, conductivity and impedance spectroscopy with extended output signal amplitude range, too.

Like the ZG4 test interface, the POT/GAL interfaces have two differential high impedance voltage input channels for 2, 3 and 4 electrode measurement arrangements. 

3 electrode arrangements are the standard for electrochemical measurements with potentiostat control. In addition, 3 or 4 electrode techniques can be advantageously used in order to partly compensate electrode - sample interface polarization or contact impedance effects.
The POT/GAL voltage channel input impedance is 10¹² Ω | 10 pF, exceeding the range of most competing instruments by several orders of magnitude - a major improvement in EIS instrumentation.

In order to reduce the capacity of the cables that connect the voltage inputs to the voltage electrodes, the two voltage inputs support driven shield technology which keeps the potential of the outer coaxial cable shield at nearly the same potential as the sensitive inner cable conductor.

Special features

• Includes a 4 channel 24 bit digitizer for simultaneous dc signal measurements of the counter-, two reference- and the working electrodes.
• High accuracy working electrode current input converter with reference technique for accurate measurement of strong conductors and insulators.
• Supports non-linear EIS by higher harmonic measurements both on instrument and WinDETA application software level.
• Automatic dc level shifters at the working and reference electrodes inputs compensate dc voltage and current offsets in order to accurately measure the small superimposed ac signals for EIS.
• All system functions are controlled by simple high level commands via the Alpha-A mainframe GPIB port. This feature allows easy integration in own software or combination with other automated equipment like, e.g., temperature, pressure or atmosphere control.
• For sample protection, the high-power counter electrode signal output supports fast voltage and current limiters independent of the main control loop. Both voltage and current limits are continuously adjustable and operate simultaneously both in potentiostat and galvanostat mode.
• Supports real-time measurements by up to 150 impedance data points / second (option) and 1.500 voltage current data points / second in time domain mode.