Application Notes

Many variables affect the outcome of  your electrochemical experiments.  We have prepared a series of Application and Technical Notes to assist you in getting the most accurate results and the best performance possible from your Gamry instrument.  

These Application Notes have been created to share our knowledge of electrochemical instruments, principles, and methods.  It is not our intention to promote our products in this section of our Website. We do, however, reference our own products for the convenience of our users, to whom we are forever grateful.

Accuracy Contour Plots

If you want to know how a potentiostat works, then read our Potentiostat Primer.  But how do you know your potentiostat is working in YOUR experiment with YOUR sample?  Understanding the implications of the Accuracy Contour Plot allows you to make an informed judgment of the validity of your electrochemical experiment.

Trouble-Create Customized EIS Circuit Elements

For the first time in any commercial EIS Fitting Software, a component can be added by the user.  You just need to be able to calculate the impedance as a function of its own parameters and frequency.

 

Trouble-Shooting Your Gamry Potentiostat with the Universal Dummy Cell 4
When doing serious electrochemistry, you want to be sure your potentiostat is functioning properly.  Fortunately, that's easy to do, especially with the Universal Dummy Cell 4 that is included with every Gamry Potentiostat.    
 

EIS Measurement of a Very Low Impedance Lithium Ion Battery

Low impedance samples, such as batteries and fuel cells, give rise to that evil actor...inductance.  Simple things, like the orientation of your cell cables, begin to matter.  Read more...
 

Verification of Low Impedance EIS Using a 1 mOhm Resistor

Making an EIS measurement on a low impedance sample is treacherous territory.  Find out why...

 

Potentiostat Primer

The Potentiostat is the fundamental electronic instrument in electrochemistry.  Gamry Potentiostats are built for high performance and flexibility -- the software tailors the potentiostat for the application.  Here's how a Potentiostat works.

Faraday Cage

You've heard of a Faraday Cage, but here's the detail you always wanted but couldn't find.  Neither could we!  If your electrochemical experiments deal with low currents (< 1 µA), you need a Faraday Cage!

 

Getting Started with Electrochemical Corrosion Measurement

An electrochemical corrosion measurement system is a virtual necessity in the modern corrosion laboratory.  Electrochemical techniques are fast, sensitive, and accurate.  And (ta-da!) they're even easy to use because they primarily consist of standardized procedures.  The hard part is getting started, so take a look at this Application Note on DC Corrosion Techniques.  It's a brief-but-thorough introduction to the subject with several very good references for further reading.

Basics of Electrochemical Impedance Spectroscopy

Not familiar with the basic concepts of Electrochemical Impedance Spectroscopy?   The Basics of EIS Application Note will answer all your questions in an easy-to-understand format and even provides a list of references for additional information. We revisited this Application Note in early 2008 and brought it up-to-date.

Determination of Double-Layer Capacitance from a Constant Phase Element

The Constant Phase Element is used by many researchers to fit an equivalent circuit to their EIS data.  The CPE is described by some as an "imperfect capacitor" and there are many cases where a CPE fits much better than a capacitor, suggesting that an electrochemical interface may be, in fact, imperfect.  Nevertheless, the interpretation of the CPE is not well understood by many in the research community.  Several researchers have suggested approaches to the employment of the CPE in the real world. Dr. Vladimir Jovic of the University of Belgrade has surveyed this literature and summarizes it here. Our thanks to Dr. Jovic for sharing his insight.    
 

Reference Electrodes

Experiencing problems with your reference electrode?  Be sure to see this Application Note on Reference Electrodes and how they can influence the operation of your potentiostat and experimental results.

Equivalent Circuit Modeling in EIS

The first step in the analysis of your EIS data is to choose an equivalent circuit that represents your chemistry system.  Then you use the software of your choice to fit that model to your EIS data.  But to get the best fit to your data, you need to help the algorithm by providing fairly accurate initial guesses for the values of the various elements in your equivalent circuit.  The Application Note on Equivalent Circuit Modeling walks you through the process of fitting your data for both a coated sample and a battery.  Written in a conversational tone and even showing what happens when you pick bad values for your elements, this Note is the best example we've seen on a very important but rarely discussed topic.

EIS on Coated Specimens

Not sure how your potentiostat may affect the results of your EIS experiment when applied to coated specimens?  Be sure to see the EIS on Coatings Application Note to answer these questions and more.

Multiplexed EIS on Coated Specimens   

An Electrochemical Multiplexer, such as the Gamry Instruments’ ECM8, can lower the labor requirements and instrumentation costs of an EIS test program. The ECM8 allows 8 samples to be connected to a single EIS instrument. An EIS spectrum can be measured on each sample in a sequential manner.  

The Applicaton Note on Multiplexed EIS on Coated Specimens will help you understand the limitations associated with performing these experiments through an ECM8 Electrochemical Multiplexer.  In addition, we will cover some basic EIS techniques and show you how to set up your EIS300 Software, ECM8 Electrochemical Multiplexer to perform your own testing. 

We have included A/B plots depicting the differences between running these experiments using a solo potentiostat and a Potentiostat/Multiplexer combination.  This Application Note will help you determine if using a Multiplexer is right for your application.

Measurement of Small Electrochemical Signals

As the current in your electrochemical experiment becomes smaller and smaller, you may approach the limit of your potentiostat.  Our Application Note on Small Electrochemical Signals describes the various factors that come into play as you push the sensitivity of your instrument.  

Understanding iR Compensation

What is iR Compensation?  When should I worry about using it?  What are the common techniques for measuring it?  Be sure to see Understanding iR Compensation  for answers to these questions.

Checking the Impedance of Your Reference Electrode

The Reference Electrode is, by far, the most common source of problems in the typical electrochemical cell.  And the most common problem with your Reference Electrode is that the impedance is too high.  To evaluate cell problems, you need to measure the impedance of your Reference Electrode.
 

Rapid Electrochemical Assessment of Paint (REAP)

Improve testing accuracy for coatings while decreasing your test time with the REAP Test.   The REAP Application Note details procedures for measuring Time To Failure (TTF) of coated metals.  REAP involves data acquisition over a 24 hour period on several samples.  The data is then analyzed to extract three parameters that can be used to estimate the relative time to failure of coatings.  

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Last revised on Thursday, May 14, 2009