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Optional Add-On Modules for Metrohm Autolab systems You are here: Metrohm USA >> Products >> Electrochemistry >> Metrohm Autolab Potentiostat/Galvanostats
Unlimited possibilities! The various modules, described below, allow you to customize your Autolab PGSTAT to your needs. The FRA2 impedance module and the current booster units are listed separately. The ADC10M module increases the sampling rate from 50 kHz to 10 MHz, giving you the ability to acquire fast transients with intervals down to 100 nano second. When combined with the SCAN-250 module, you can perform cyclic voltammetry measurements with scan rates up to 250 kV/s, making it a powerful tool for studying fast kinetic processes.
The staircase method for cyclic voltammetry is widely used in digital instruments as the currents due to the charging of the double layer are reduced if the duration of the step is sufficiently long. This results in data that can be treated as originating from faradaic processes only. When the processes exhibit very fast transient behavior, such as hydrogen adsorption, digital sweep can lead to loss of information regarding the adsorption process. The SCAN250 module, which has the capability of applying a true analog sweep to the sample, was specially designed to overcome this problem. The true linear scan rate range is from 10 mV/s to 250 kV/s. The SCAN250 module in combination with ADC10M is a very powerful tool for studying fast transients.
The MUX module series allows you to perform electrochemical experiments on multiple cells sequentially. The cell to perform measurement on can be selected either manually or automatically using the software option “Project Mode.” Eco Chemie offers three types of MUX modules:
The BA is a dual-mode bipotentiostat module that converts the Autolab into a double channel potentiostat with which measurements on 2 working electrodes can be performed sharing the same counter and reference electrode. In the standard mode, a fixed potential is applied to the second channel (second Working Electrode) while applying a potential step or a sweep to the first channel (first Working Electrode). In the optional scanning bipotentiostat mode, a potential offset with respect to the first channel is applied to the second channel. The BA module has 7 current ranges (10 nA - 10 mA) available. The current range during measurement can be either fixed manually or selected automatically by the software, the maximum current is 50 mA.
The BA module is available in a MultiBA configuration in which up to 5 extra channels, sharing the same counter and reference electrode, can be added to the Autolab (PGSTAT128N or PGSTAT302N), one for each additional BA module. Each extra channel has an independent offset with respect to the reference electrode (in standard mode) or the first channel (in scanning bipotentiostat mode). The mode of each channel can be set independently, the maximum current is 50 mA.
The EQCM module provides the means to perform Electrochemical Quartz Crystal Microbalance experiments. The EQCM module measures a mass change per unit area by recording the change in resonant frequency of a quartz crystal oscillator. Measurements in the sub μg/cm2 are possible. The EQCM can be fitted with 6 MHz, AT-cut crystals. An application note is available: EQCM study of underpotentially deposited (UPD) lead adlayer on gold The module comes with a dedicated electrochemical cell and is supported in NOVA only. The specifications are:
During localized corrosion, electrochemical noise (ECN) is generated by a combination of stochastic (random) processes, such as breakdown of passive films and repassivation. Electrochemical noise is an in-situ technique for measuring these localized corrosion processes on bare or coated metal samples. During measurements with the ECN module, no external perturbation (potential or current) is applied to the electrode. The potential and current signals are measured as a function of time.
The lowest current range available on the standard Autolab is 10 nA. At this current range, the Autolab has a current resolution of 30 fA. When doing measurements on microelectrodes, some times even higher resolution is needed. Originally designed for electrochemical detection (ECD) in HPLC and FIA, the ECD module makes the measurement of such low currents possible. The ECD module provides two additional current ranges of 1 nA and 100 pA, giving a minimum current resolution of 0.3 fA. The ECD module also has a built-in third-order Sallen-Key filter, with three RC-time constants that help to filter out noise.
The FI20 filter and integrator module allows you to do coulometric and chronocoulometric experiments. The analog integrator gives you the possibility to measure charge instead of current, and it can be used both in cyclic voltammetry as well as in potential step experiments. With this module, it is easy to separate the capacitive current from the faradaic current. In addition the integrator is effective in reducing signal noise by averaging it out. The third-order Sallen-Key filter with selectable RC-times between 0 and 500 ms can be used to filter out noise. The module is also useful in cases where the background noise (50 Hz or 60 Hz, for example) cannot be removed by using measures like a Faraday cage.
With the pX1000 module installed in an Autolab instrument, you can measure pH or pX and temperature in parallel with an electrochemical measurement. You can connect any pH, pX or “double” electrode to the pH module. In case an electrode other than a pH electrode is used, the output is given as the voltage difference that is measured between the electrodes making it possible to connect a detection electrode to perform coulometric titration. The pX module also works as an independent pH meter.
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