General features

• ±10V ±10mA
• Positive Feedback Control
• Current offset control
• Fully protected
• Current Auto-Ranging
• PC interfacing available

The Model 2059 is a low-cost Potentiostat/Galvanostat designed to satisfy the requirements of scientists working in fields of electrochemical cells measurements with low noise are necessary.

The model 2059 offers several features making it very acctrative for high precision laboratory applications and well-suited for computer-controlled experiments. Among its many features implemented, the Model 2059 offers a 4 1/2 digit LCD display for clear and accurate reading of both current and potentials, the option for a battery power supply to minimize noise and ground loop problem, and special current-offset circuitry for precise observation of low current deviations. A microprocessor controlled current-range selectro with a fully AUTOMATIC function allows the instrument to search and adjust to the optimum curren range from 1 nA to 10 mA in few milliseconds. Continuous control of the IR drop can be accomplished by the POSITIVE-FEEDBACK iR compensation function.

Both current and potential values are continuously available on the front panel display along with all digital I/O for current ranges and cell control. This greatly simplifies the connection to a standard PC data acquisition board. The availability of specialized Windows driving software (AMEL "SOFTASSIST" PACKAGE) makes the model 2059 simple to install and easy to use even by non-specialists.

Master Unit Operating Principle

The main amplifier A1 provides the output current, voltage swing, gain and summing node for the various inputs and feedback. The electrochemical cell is connected with the COUNTER electrode to the output of A1 through a set of calibrated shunt resistors for precise current measurement and the WORKING electrode is electrical common. The differential amplifier A 2measures the voltage between the REFERENCE and WORKING and provides the negative feedback signal for potentiostatic mode operation. A 3is a unity-gain buffer amplifier for the current signal and for negative feedback in galvanostatic mode. The output of A 3is amplified 10 fold by A 4and the signal (eventually filtered out) is used to control the POSITIVE FEEDBACK amount when iR compensation is required. The reference source is connected to a multi-turn potentiometer for precise setting of the cell potential. The current signal at the output of A 3is monitored by the auto-ranging circuitry providing automatic range switching (when enabled). All signals (current, reference and standard source) can be monitored with the built-in DVM. The voltage and current monitor can be filtered before data acquisition.

Technical Specifications

Output voltage: ±10V Output current: ±10mA (Continuous) Short circuit current: ±20mA (Continuous) Controlled potential range: ±5V Controlled potential resolution: ±1mV Operating modes: Potentiostat or Galvanostat (floating or grounded) Galvanostat ranges: 8 decades 1nA up to 10mA Galvanostat setting resolution 0.1% of the selected range Reference input leakage current: =< 10pA @ 25°C iR drop compensation: Method; Positive feedback Feedback control; Ten-turn micrometric dial Compensation range: Up to 200% of the full-scale selected iR drop filter: Allows to compensate more than the 100% without spurious oscillations Current backing-off circuit: Range 100% of I OUT scale Overall response time: (Potentiostat, 100 µA range); =<100 µsec (Potentiostat, 10 mA range); =<50 µsec Output ripple and noise: Wideband 4 kHz - ±50 µV peak-to-peak at 1 kOhm load Potential stability: (VS line voltage) - ±100 µV (for 10% variation) (VS temperature) - ±5 µV/°C (VS time) - ±100 µV/week Display: 4 1/2 digit LCD, 20mm characters Output filter (I OUT - V OUT): None - No filtering A - 50 Hz filter (60 Hz on request) B - 500 msec time constant (other values available on demand at order level) Overload protections: Voltage (reference input) - ±10V D.C. continuous Current - Permanent output short-circuit allowed Interfacing capability: Digital I/O for cell and current ranges. Current and potential monitor. Power supply: From line 110-200Va.c. 40-60 Hz - 40VA; From lead acid battery 3A/h ±18Vdc Battery Charger: Automatic charge with current limiter Body: Alluminium fusion chassis Dimensions & weight: 440x150x420mm depth, 12.5kg