Overview

The Model 700D series are computerized general-purpose potentiostat / bipotentiostat / galvanostat instruments. A typical application involves a rotating ring-disk electrode (RRDE), but these systems can also be used for other applications where dual channel measurements are essential, such as dual channel electrochemical detection. The system contains a fast digital function generator, high speed data acquisition circuitry, (bi)potentiostat, and a galvanostat (only available in select models). The potential control range is ±10 V and the current range is ±250 mA. The instrument is capable of measuring current down to tens of picoamperes. The steady state current of a 10 μm disk electrode can be readily measured without external adapters. With the CHI200B Picoamp Booster and Faraday Cage (fully automatic and compatible with the CHI700D series), currents down to 1 pA can be measured (primary current channel only). These instruments are very fast. The function generator can update at a 10 MHz rate, and the maximum sampling rate is 1 MHz at 16-bit resolution. The instrument provides a very wide dynamic range on experimental time scales. For instance, the scan rate in cyclic voltammetry can be up to 1000 V/s with a 0.1 mV potential increment or 5000 V/s with a 1 mV potential increment. The potentiostat / galvanostat uses a 4-electrode configuration, allowing it to be used for liquid/liquid interface measurements and eliminating the effect of the contact resistance of connectors and relays for high current measurements. The data acquisition systems allow an external input signal (such as spectroscopy signals to be recorded simultaneously with electrochemical data). The instrument will also automatically re-zero both potential and current, so that periodic re-calibration of the instrument can be avoided.

The 700D series shares many common features with the 600D series. When used as a single channel potentiostat, the instrument is identical to the model 600D series. The bipotentiostat is realized by adding the second channel potential control and current measurement board to the model 600D series. There are also two filter stages, three extra gain stages, and channel selection circuitry on the board. When it is used as a bipotentiostat, the second channel can be controlled at an independent constant potential or to scan/step at the same potential as the first channel. In case of CV, it can also scan with a constant potential difference with the first channel. Techniques available for the second channel include CV, LSV, SCV, CA, DPV, NPV, SWV, and i-t.

The 700D series is the upgrade to our very popular 700/700A/700B/700C series. The instrument utilizes flash memory, allowing instrument updates to be distributed electronically instead of the inconvenient shipment of an EPROM chip.

The 700D series has a USB port (default) and a serial port for data communication with the PC. You can select either USB or serial (but not both) by changing a switch setting on the rear panel of the instrument.

The 700D series also has a true integrator for chronocoulometry.

16-bit highly stable bias circuitry is used for current or potential bias. This allows wider dynamic range in AC measurements. It can also be used to re-zero the DC current output.

When used as a single channel potentiostat, the instrument is identical to the model 600D series. The bipotentiostat is realized by adding the 2nd channel potential control and current measurement board. When it is used as bipotentiostat, the 2nd channel can be controlled at a independent constant potential, to scan or step at the same potential as the first channel, and to scan with a constant potential difference with the first channel.

The instrument also provides various electrochemical techniques, integrated digital CV simulator, and an impedance simulation and fitting program. These features provide powerful tools for both electrochemical mechanistic studies and trace analysis.

We provide several different models in the 700D series. The model comparison table compares the different models. Other than what is listed, the specifications and features of these models are identical. Models 700D and 710D are basic units for mechanistic study and electrochemical analysis, respectively. Models 720D and 730D are comprehensive electrochemical analyzers. Model 750D and 760D are advanced electrochemical workstations.

Specifications

Potentiostat Bipotentiostat Galvanostat Potentiostat rise time: < 1 μs Potential range: ±10 V for both channels Compliance voltage:  ±12 V Current: 0.25 A if single channel, or 0.25 A total for two channels Input impedance of reference electrode:  1012 ohm Sensitivity scale:  1x10-12 - 0.1 A/V in 12 ranges Input bias current:  < 50 pA Current measurement resolution:  < 0.01 pA Minimum potential increment in CV:  100 μV Potential update rate:  10 MHz Fast data acquisition: 16 bit @ 1 MHz External voltage signal recording channel External potential input Automatic and manual iR compensation Automatic potential and current zeroing

CV and LSV scan rate:  0.000001 to 5000 V/s Potential increment during scan:  0.1 mV @ 1000 V/s CA and CC pulse width:  0.0001 to 1000 sec CA and CC Steps: 320 True integrator for CC DPV and NPV pulse width:  0.001 to 10 sec SWV frequency:  1 to 100 kHz ACV frequency:  0.1 to 10 kHz SHACV frequency:  0.1 to 5 kHz IMP frequency:  0.00001 to 100 kHz (extend to 1M Hz for impedence 10-1000 ohm) IMP amplitude:  0.00001V to 0.7V RMS Potential, current low-pass filters, covering 8-decade frequency range, Automatic and manual setting RDE rotation control voltage output:  0 - 10 V Cell control: purge, stir, knock Flash memory for quick software update Serial port or USB selectable for data communication Maximum data length:  128K-4096K selectable Dimensions:  14.25”(W) x 9.25”(D) x 4.75”(H) Weight:  12 Lb.

Model Comparison

Functions	700D	710D	720D	730D	750D	760D
Cyclic Voltammetry (CV)*	●	●	●	●	●	●
Linear Sweep Voltammetry (LSV) &,*	●	●	●	●	●	●
Staircase Voltammetry (SCV) #,&,*				●	●	●
Tafel Plot (TAFEL)				●	●	●
Chronoamperometry (CA)*	●		●	●	●	●
Chronocoulometry (CC)	●		●	●	●	●
Differential Pulse Voltammetry (DPV) #,&,*		●	●	●	●	●
Normal Pulse Voltammetry (NPV) #,&,*		●	●	●	●	●
Differential Normal Pulse Voltammetry (DPNV)#,&						●
Square Wave Voltammetry (SWV) &,*			●	●	●	●
AC Voltammetry (ACV) #,&,$				●	●	●
2nd Harmonic AC Voltammetry (SHACV) #,&,$				●	●	●
Amperometric i-t Curve (i-t)*				●	●	●
Differential Pulse Amperometry (DPA)						●
Double Differential Pulse Amperometry (DDPA)						●
Triple Pulse Amperometry (TPA)						●
Integrated Pulse Amperometric Detection (IPAD)						●
Bulk Electrolysis with Coulometry (BE)	●		●	●	●	●
Hydrodynamic Modulation Voltammetry (HMV)					●	●
Sweep-Step Functions (SSF)					●	●
Multi-Potential Steps (STEP)					●	●
AC Impedance (IMP)					●	●
Impedance - Time (IMPT)					●	●
Impedance - Potential (IMPE)					●	●
Chronopotentiometry (CP)						●
Chronopotentiometry with Current Ramp (CPCR)						●
Multi-Current Steps (ISTEP)						●
Potentiometric Stripping Analysis (PSA)						●
Electrochemical Noise Measurement (ECN)						●
Open Circuit Potential - Time (OCPT)	●	●	●	●	●	●
Galvanostat						●
RDE control (0-10V output)				●	●	●
Full version of CV simulator				●	●	●
Limited version of  CV simulator	●	●	●
Impedance Simulation and Fitting					●	●
iR Compensation	●	●	●	●	●	●
External Potential Input	●	●	●	●	●	●
Auxiliary Signal Measurement Channel	●	●	●	●	●	●

#: Corresponding polarographic mode can be performed.

&: Corresponding stripping mode can be performed.

$: Phase selective data are available.

*: Second channel (bipotentiostat mode) can be performed.