Gamry Instruments PCI4/300 Potentiostat/Galvanostat/ZRA User manual
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PCI4 Potentiostat/Galvanostat/ZRA
Operator's Manual
includes both the
PCI4/300 Potentiostat/Galvanostat/ZRA
and
PCI4/ 50 Potentiostat/Galvanostat/ZRA
Copyright 1997-2011 Gamry Instruments, Inc. All rights reserved. rinted in the USA.
Revision 5.2
February 28, 2011
i
ii
Limited Warranty
Gamry Instruments, Inc., warrants to the original user of this product that it shall be free of defects resulting
from faulty manufacture of the product or its components for a period of two years from the date of shipment.
Gamry Instruments, Inc., makes no warranties regarding either the satisfactory performance of the CI4 or the
fitness of the instrument for any particular purpose. The remedy for breach of this Limited Warranty shall be
limited solely to repair or replacement, as determined by Gamry Instruments, Inc., and shall not include other
damages.
Gamry Instruments, Inc., reserves the right to make revisions to the CI4 at any time without incurring any
obligation to install same on instruments previously purchased. All instrument specifications are subject to
change without notice.
There are no warranties which extend beyond the description herein. This warranty is in lieu of, and
excludes any and all other warranties or representations, expressed, implied or statutory, including
merchantability and fitness, as well as any and all other obligations or liabilities of Gamry Instruments,
Inc., including but not limited to, special or consequential damages.
This limited warranty gives you specific legal rights and you may have others which vary from state to state.
Some states do not allow for the exclusion of incidental or consequential damages.
No person, firm, or corporation is authorized to assume for Gamry Instruments, Inc., any additional obligation
or liability not expressly provided herein except in writing duly executed by an officer of Gamry Instruments,
Inc.
iii
Disclaimers
Gamry Instruments, Inc., cannot guarantee that the CI4 otentiostat will work with all computer systems,
operating systems, or third party expansion cards and peripherals.
The information in this manual has been carefully checked and is believed to be accurate as of the time of
printing. However, Gamry Instruments, Inc., assumes no responsibility for errors that might appear.
Copyrights and Trademarks
CI4 otentiostat Operator's Manual Copyright 1997-2011 Gamry Instruments, Inc. All rights reserved.
rinted in the USA.
Gamry Framework Copyright 1989-2011 Gamry Instruments, Inc.
C4, CI4, Gamry Framework, DC105, EIS300, and Gamry are trademarks of Gamry Instruments,
Inc.
Windows is a trademark of Microsoft Corporation.
No part of this document may be copied or reproduced in any form without the prior written consent of Gamry
Instruments, Inc.
iv
If You Have Problems
Contact us at your earliest convenience. We can be contacted via:
Telephone (215) 682-9330 8:30 AM - 6:30 M US Eastern Standard Time
Fax (215) 682-9331
Mail Gamry Instruments, Inc.
734 Louis Drive
Warminster, A 18974
USA
If you write to us about a problem, provide as much information as possible.
If you are having problems with installation or use of your CI4 otentiostat, it would be helpful if you called
from a phone near to your computer, where you can type and read the screen while talking to us.
We are happy to provide a reasonable level of free support for registered users of our products. Reasonable
support includes telephone assistance covering the normal installation and use of the CI4 in standard
computer hardware.
We provide a two year warranty covering both parts and labor. A service contract that extends the warranty is
available at an additional charge.
Enhancements to the CI4 that require significant engineering time on our part may be available on a contract
basis. Contact us with your requirements.
Table of Contents
Limited Warranty.................................................................................................................... ii
Disclaimers ............................................................................................................................. iii
Copyrights and Trademarks ..................................................................................................... iii
If You Have roblems ............................................................................................................. iv
Chapter 1 -- Introduction ........................................................................................................ 1-1
About This Manual..................................................................................................... 1-1
CE Compliance Required for Sale in Europe ............................................................... 1-1
About the CI4.......................................................................................................... 1-1
otentiostat Schematic Diagram................................................................................. 1-2
Notational Conventions.............................................................................................. 1-5
Chapter 2 -- Installation ......................................................................................................... 2-1
Computer Requirements ............................................................................................ 2-1
CI Compatibility....................................................................................................... 2-1
Multiple otentiostat Systems..................................................................................... 2-2
Card Identification ..................................................................................................... 2-2
ositional Conventions............................................................................................... 2-2
Handling the Cards .................................................................................................... 2-3
lug & lay System Configuration............................................................................... 2-3
Installing the Cards in Your Computer......................................................................... 2-3
Connecting the Internal Cables................................................................................... 2-4
Cell Cable Installation................................................................................................. 2-5
1
st
Time Device Installation in Windows ..................................................................... 2-5
Multiple otentiostat Systems..................................................................................... 2-8
Device Manager......................................................................................................... 2-9
Authorization Codes and Label................................................................................... 2-9
Application Software Installation and System Checkout............................................... 2-10
Calibration................................................................................................................. 2-11
Chapter 3 -- Cell Cable Connections ...................................................................................... 3-1
Cell Indicator ............................................................................................................. 3-1
Normal Cell Connections ........................................................................................... 3-1
ZRA Mode Cell Connections ...................................................................................... 3-3
Membrane Cell Connections...................................................................................... 3-3
Chapter 4 -- Stability in otentiostat Mode ............................................................................. 4-1
Capacitive Cells and Stability...................................................................................... 4-1
Improving otentiostat Stability .................................................................................. 4-2
Chapter 5 -- Measurement of Small Signals............................................................................. 5-1
Overview................................................................................................................... 5-1
Measurement System Model and hysical Limitations................................................. 5-1
Johnson Noise in Zcell .................................................................................. 5-2
Finite Input Capacitance ............................................................................... 5-3
Leakage Currents and Input Impedance......................................................... 5-3
Voltage Noise and DC Measurements ........................................................... 5-4
Shunt Resistance and Capacitance................................................................. 5-4
Hints for System and Cell Design................................................................................ 5-5
Faraday Shield .............................................................................................. 5-5
Avoid External Noise Sources ........................................................................ 5-5
Cell Cable Length and Construction............................................................... 5-5
Lead lacement ............................................................................................ 5-6
Cell Construction .......................................................................................... 5-6
Reference Electrode ...................................................................................... 5-6
Instrument Settings........................................................................................ 5-7
EIS Speed ..................................................................................................... 5-7
Ancillary Apparatus ....................................................................................... 5-7
Floating Operation..................................................................................................... 5-7
Appendix A -- CI4/300 Specifications ................................................................................... 6-1
Appendix B -- CI4/750 Specifications ................................................................................... 6-3
Appendix C -- Changing CI4 Settings ..................................................................................... 6-5
Overview................................................................................................................... 6-5
About the "GAMRY5.INI" File ..................................................................................... 6-6
Using Notepad to alter "GAMRY5.INI" ........................................................... 6-7
Removing a otentiostat from an Existing System........................................................ 6-7
Interrupt Level Setting ................................................................................................ 6-8
Register Address......................................................................................................... 6-8
Changing the Auxiliary Analog Output Scaling ............................................................ 6-8
Appendix D -- I/O Connections for the CI4............................................................................ 6-9
CE Compliance, EMI and Cable Shielding................................................................... 6-9
Grounds and the CI4 otentiostat............................................................................. 6-9
The Cell Connector.................................................................................................... 6-10
Aux A/D Input............................................................................................................ 6-11
Control Signal Input ................................................................................................... 6-12
I Channel Output....................................................................................................... 6-13
V Channel Output...................................................................................................... 6-13
Miscellaneous I/O Connector ..................................................................................... 6-14
Appendix E – Auxiliary A/D Input Characteristics ..................................................................... 6-15
Overview................................................................................................................... 6-15
Jumper Identification ................................................................................................. 6-15
Input Impedance Selection......................................................................................... 6-15
Filter Selection........................................................................................................... 6-16
Aux A/D Specifications............................................................................................... 6-16
Appendix F – CE Certificate..................................................................................................... 6-17
Certificate of Conformance ........................................................................................ 6-17
Comprehensive Index ............................................................................................................. 7-1
Chapter 1 -- Introduction -- About This Manual
1-1
Chapter 1 -- Introduction
About This Manual
This manual covers the installation and use of the CI4 otentiostat/Galvanostat/ZRA. It covers both the
CI4/300 otentiostat/Galvanostat/ZRA and its cousin the CI4/750 otentiostat/Galvanostat/ZRA. These
instruments differ primarily in their output current: 300 mA for the CI4/300 and 750 mA for the CI4/750.
Throughout this manual, the term CI4 should be interpreted as a reference to both the CI4/300 and the
CI4/750.
NOTE: The Gamry Instruments CI4 interfaces to a computer using the industry standard CI bus.
This manual does not discuss the older Gamry Instruments C4 family of potentiostats, which used the
ISA bus. The C4 and CI4 perform similarly, but the installation procedures and specifications
between the older and newer instruments are different enough to make this document a poor
reference for the C4. Consult an earlier revision of this manual for C4 information.
This manual describes use of a CI4 with Revision 5.0 (and later revisions) of the Gamry Framework software.
It is equally useful when setting up a newly purchased potentiostat or modifying the setup of a four-year-old
potentiostat for use with new software.
The bulk of Chapter 1 is an overview of the CI4's design and modes of operation. Chapter 2 contains CI4
installation instructions. Chapter 3 describes cell cable connections. Chapter 4 covers the difficult issues of
potentiostat stability and approaches to prevent oscillation. Chapter 5 discusses the realities of low current,
high impedance measurements.
You will find dry technical material such as specifications and connector pin-outs in the Appendices.
This manual does not discuss software installation or operation.
Software support for the CI4 is described in the Gamry’s On-line Help system. All the Gamry Instruments'
applications which run under the Gamry Framework control the CI4 via a STAT object. See the Framework’s
On-line Help for information concerning STAT objects and their functions.
CE Compliance Required for Sale in Europe
The European Community has instituted standards limiting radio frequency interference from electronic devices
and mandating several safety requirements. Gamry Instruments has modified its instruments to comply with
these standards. We are shipping CE compliant instruments to all destinations.
The relevant CE regulations include EN 61010 and EN 61326..
About the PCI4
The CI4 otentiostat is a research grade electrochemical instrument compact enough to fit inside a computer.
It can operate as a potentiostat, a galvanostat, or a ZRA (zero resistance ammeter).
Chapter 1 -- Introduction -- Potentiostat Schematic Diagram
1-2
The CI4/300 and CI4/750 are two members of Gamry Instruments’ CI4 otentiostat family. They share a
number of characteristics with the other members of this family, especially in the areas of signal generation and
signal preconditioning prior to A/D conversion.
CI4 features include 9 decade current auto-ranging, electrical isolation from earth ground, current interrupt iR
compensation, and extensive filtering. A sine wave generator on the CI4 allows its use for impedance
measurements at frequencies up to 300 kHz.
The CI4 consists of two printed circuit cards that install directly into a computer. Each card requires one
expansion slot in an AT compatible computer. The cards are interconnected by one ribbon cable. Depending
on the number of available slots, up to four CI4 card sets can be installed in one computer.
The first card is called the otentiostat Card. It contains the analog potentiostat circuitry and its associated
isolated power supply. This card is not directly connected to the computer's AT bus, except for the 5V power
and its ground. It communicates with the computer over serial lines isolated by opto-couplers on the other
card. The otentiostat card can be switched to act as a high performance Galvanostat or as a ZRA (Zero
Resistance Ammeter).
The second printed circuit card will be referred to as the Controller Card. It contains a CI bus interface, opto-
coupled serial transfer logic, an isolated power supply, a signal generator, and a high performance measurement
system.
• The CI bus interface communicates with the rest of the CI4 over opto-coupled serial lines. There is no
ground connection between the CI bus circuitry and the analog circuits in the CI4.
• Each card contains an isolated DC/DC converter. The power supply on the Controller card converts the
computer’s 12 volt supply into the voltages needed to power its own analog circuitry. The power supply on
the otentiostat card converts the computer’s 5 volt supply into a variety of voltages.
• The standard "DC" signal generator on the Controller Card uses two 16 bit D/A converters. A DDS sine
wave generator is packaged on a small "piggyback card" that plugs into the Controller card.
• The Controller Card measurement circuitry includes signal filtering, offset, and switchable gain on two
independent measurement channels. The output of these channels is measured using a 16 bit A/D
converter.
Potentiostat Schematic Diagram
If you are not familiar with electronic schematics or potentiostats, you probably want to skip this section. This
information is for expert use only and is not required for routine use of the CI4 otentiostat.
Figure 1-1 is a highly simplified schematic diagram. It shows the analog portion of the otentiostat in its
potentiostatic control mode.
Chapter 1 -- Introduction -- Potentiostat Schematic Diagram
1-3
Figure 1-1
PCI4 Analog Circuits in Potentiostat Mode
Chapter 1 -- Introduction -- Potentiostat Schematic Diagram
1-4
A few points concerning this schematic:
• The circuits on the right side of the schematic are on the otentiostat card and those on the left are on
the Controller Card. The dotted line shows the separation between the two portions of the
instrument. The analog signals sent between the portions are received in differential amplifiers to
eliminate grounding problems.
• Arrows pointing into a circuit indicate a computer control input.
• The labels CE , RE and WE stand for counter electrode, reference electrode and working electrode
respectively.
• There are two 16 bit D/A converters generating the computer controlled portion of the applied cell
voltage.
• The I/E converter uses a series resistor to measure the cell current. The circuit actually uses eight
decade resistors that can be switched in under computer control.
• The cell switch is actually two switches in series - a relay for low leakage and an FET switch for fast
response.
• The label OL refers to overload protection.
• Gains and resistor values are not shown.
• Two capacitors can be switched across the I/E converter resistor. These capacitors are used for
filtering and stability compensation.
• The control amplifier is shown at the upper right side of the schematic. Compensation capacitors can
be switched across the control amplifier to adjust its bandwidth and improve potentiostat stability.
• The A/D converter is a 16 bit successive approximation type converter.
• Some analog circuits, including overload detection circuitry, positive feedback IR compensation, the
auxiliary D/A converter, power circuits, and data acquisition controls are not shown.
• All digital circuits, including the AT bus interface, timers, state machines, opto-couplers, and digital I/O
are not shown.
• Timing for both data acquisition and D/A update in the signal generator is controlled by a state
machine working with a crystal oscillator generated clock. A busy processor in the computer cannot
create timing jitter.
Chapter 1 -- Introduction -- Notational Conventions
1-5
Notational Conventions
In order to make this manual more readable we have adopted some notational conventions. These are used
throughout this manual and all other Gamry Instruments manuals.
• Numbered lists. A numbered list is reserved for step by step procedures, with the steps always
performed sequentially.
• Bulleted List. The items in a bulleted list, such as this one, are grouped together because they
represent similar items. The order of items in the list is not critical.
• File names and folders. Inside paragraphs, references to computer files and Windows folders will be
capitalized and placed within quotes, for example: and “C:\FRAMEWORK\FRAMEWORK.EXE" and
“WIN.INI".
Chapter 1 -- Introduction -- Notational Conventions
1-6
Chapter 2 -- Installation -- Computer equirements
2-1
Chapter 2 -- Installation
A CI4 otentiostat is only useful after it has been installed in a Windows compatible computer.
If you purchase a CI4 in a system that includes both a computer and an applications software package, Gamry
Instruments, Inc. will install the CI4 (and the system software) to produce a "turn-key" system. You may ignore
this chapter if you have purchased a turn-key system.
If you buy your own computer, add a CI4 to an existing system, or move an old CI4 to a new computer, you
need to know how to install a CI4 into a computer. Read on.
Software installation is discussed in the Installation Manual for each software package. It will not be discussed
here.
Computer Requirements
Before you install a CI4 into your own computer you must make sure that your computer meets these simple
requirements.
• A computer based on one of the entium family of Intel microprocessors or a 100% compatible
processor from another vendor.
• One of the following Operating Systems: Windows 2000, or Windows X .
• Two unobstructed, full height (11 cm) CI expansion slots for each CI4 card set. Each slot must be
capable of accepting a 26 cm long (10 inch) card.
• Up to 50 watts of power supply capacity for each CI4 Card Set. This is in addition to the power
normally drawn by your computer and its standard peripherals.
• One unused disk drive power connector. This connector is used to power the CI4 Controller card.
Most of the CI4’s power is drawn from the computer's +12 volt and +5 volt supplies. However, the CI4 also
requires a small amount (< 50 mA) of current taken from the computer’s –12 volt supply.
Gamry's Windows application software packages may impose additional, more stringent requirements.
PCI Compatibility
The CI4 has been designed for compatibility with Revision 2.2 of the CI Specification. As described in that
specification, it is a universal card, able to operate with either 3.3 volt and 5.0 volt CI signaling levels.
The CI4 does not draw power from the 3.3 volt supply pins on the CI bus connector. It can therefore
operate with older computers that did not provide 3.3 volts on the CI bus. It should operate with all CI
computers compliant with Revision 2.0 and higher of the CI Specification.
Chapter 2 -- Installation -- Multiple Potentiostat Systems
2-2
Multiple Potentiostat Systems
Gamry’s current Framework software (Revision 4.2) allows a computer to operate several Gamry Instruments
potentiostats simultaneously. These can include both CI4 and older C4 family devices in the same
computer. Contact our home office or your local sales representative if you need assistance configuring a
system contain both CI4 and C4 hardware.
Gamry’s Framework contains a utility script to identify CI4 Family potentiostats in a multiple potentiostat
system. See Appendix C of the Getting Started Guide for instructions concerning the use of this program.
Card Identification
A CI4 otentiostat consists of two full height, 26 cm long CI compatible printed circuit boards. When you
look at your CI4 cards, you will notice that a large portion of one card is covered with a large black shield.
This card is the CI4 otentiostat Card. The card without the shield is referred to as the CI4 Controller Card.
Positional Conventions
Throughout this manual, reference will be made to positions on the CI4 cards. In order to avoid confusion,
we will define some conventions that describe positions on these cards.
Assume:
• The card in question is lying on a table in front of you.
• The component side of the card is up .
• The card edge (where the card plugs into the computer) is facing you.
Under these assumptions, Figure 2-1 illustrates our positional conventions.
Figure 2-1
Positional Conventions
Top
Bottom
Left Right
Chapter 2 -- Installation -- Handling the Cards
2-3
Handling the Cards
The CI4 cards, like most electronic components, are susceptible to damage from static discharges and
connection to live circuits. Some elementary precautions should be taken when handling and installing these
cards.
• The cards are shipped in anti-static bags. Leave them in these bags until you need to install or
reconfigure them.
• Always turn off your computer before plugging in any card.
• If you need to leave a card out of its anti-static bag, lay the anti-static bag on a flat surface, then lay
the card on top of the bag.
• rior to handling the cards, you should momentarily ground yourself to eliminate any static charges
on your body. A good way to accomplish this is to turn off your computer, then lightly touch your
finger to an unpainted portion of the computer's metal chassis.
• Save the anti-static bags. You must use them if the cards are shipped while not installed in a
computer. This includes occasions when the cards must be returned to Gamry Instruments, Inc. for
repair.
Plug & Play System Configuration
The CI4 Controller Card is completely compatible with the Windows lug & lay configuration system. Unlike
Gamry’s older potentiostats, you don’t need DI switches to configure the card. Like most lug & lay
hardware, it is best if you install the software for the CI4 before you install the potentiostat hardware.
A Setup program will normally startup automatically when you place the Gamry Instrument’s Software CD into
the CD drive on your computer. Consult Gamry’s software installation manual if you need assistance accessing
the Setup program or choosing options in its menus.
Installing the Cards in Your Computer
NOTE: lease review the discussion on Handling the Cards earlier in this chapter prior to proceeding.
As discussed above, it is best if you install Gamry’s Framework software before you install the CI4 hardware.
The following procedure is used to install the CI4 cards in your computer.
1. Turn off your computer.
2. Following your computer manufacturer's instructions, open up the computer to expose its expansion
card slots.
3. Locate an empty expansion slot that has a CI interface. The slot must be at least 26 cm long.
If necessary, remove the retaining screw and slot cover (the 'L' shaped metal bracket) for this slot.
Save the screw for use later.
4. Locate a second empty slot that is within 15 cm of the first. You may have to move some of your
existing cards to get two suitable slots.
Chapter 2 -- Installation -- Connecting the Internal Cables
2-4
Again, remove the retaining screw and slot cover, saving the screw for use later.
5. Remove one card from its anti-static bag.
6. lug this card into one slot. Make sure the card seats securely in the edge card connector on the
motherboard. Secure the card in the slot using the screw from Step 3.
NOTE: All the gold fingers on the lower edge on this card must be in a motherboard edge connector.
7. Repeat steps 5 and 6 with the second card, locating it in the second slot.
8. Do not close up the computer yet.
Connecting the Internal Cables
1. Locate the 26 pin headers (group of 26 pins) on both the Controller and otentiostat cards. They
are in the upper right hand side of each card.
2. Examine the ribbon cable that came with the CI4 otentiostat. Each end of this cable has a 26
pin connector on it. The two ends of the cable are identical and therefore interchangeable.
3. lug one end of this ribbon cable into the 26 pin header on the Controller card.
4. Repeat step 5 using the other end of the cable and the header on the otentiostat card. We
recommend that the colored stripe on the cable faces the left side of both cards (nearest the metal
bracket).
5. Locate the power input connector on the upper left side on the CI4 Controller card. This mates
with a “disk drive” power cable from the C’s power supply. Locate an unused power cable and
connect it to the CI4 power input connector. A power cable extender was supplied with the
CI4, in case the computer’s disk drive power cable is too short.
Note that the power cables can only mate in one direction. If the power cable will not plug into
the CI4 card, rotate the cable 180°.
6. Carefully double check your work.
7. Onc e this step is completed you may close up the computer.
Chapter 2 -- Installation -- Cell Cable Installation
2-5
Cell Cable Installation
The Cell Connector is a 9 pin female D connector on the otentiostat card.
The standard cell cable has a 9 pin D connector on one end and a number of leads terminated with banana
plugs on the other. The D connector end of the cable is connected to the Cell Connector on the otentiostat
card. The knurled screws on this cable should always be used to hold the cable in place.
Caution: Other PC functions can use female 9 pin D connectors. Make sure that
your cell cable is plugged into the correct connector before making any
connection to your cell.
1
st
Time Device Installation in Windows
When a CI4 is first connected to a computer running Windows, the Windows lug and lay Manager will see
the new device, but will be uncertain what device it is. The message that will appear is something like “New
device found” or “Unknown CI Bridge device Detected”.
When this occurs after you’ve plugged in a CI4 instrument, tell Windows that you would like to install the new
device.
Windows Users: The following windows will not be displayed. lease skip to page 2-7 to continue the
installation process.
All other users should see a screen that looks something like this:
Figure 2 - 2
Welcome to the Found New Hardware Wizard
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