Gamry Instruments IMX8 User manual

IMX8™ Multiplexer
Operator’s Manual
Copyright  2022 Gamry Instruments, Inc.
Revision 1.0
July 14, 2022
988-00087

If You Have Problems
3
If You Have Problems
Please visit our service and support page at www.gamry.com/service-support/. This page contains information
on installation, software updates, and training. It also contains links to the latest available documentation. If you
are unable to locate the information you need from our website, you can contact us via email using the link
provided on our website. Alternatively, you can contact us one of the following ways:
Internet www.gamry.com/service-support/
Telephone [phone]:00 AM−5:00 PM US Eastern Standard Time
[phone] Toll-free US & Canada Only
Please have your instrument model and serial numbers available, as well as any applicable software and
firmware revisions.
If you have problems in installation or use of a system containing an IMX8 Multiplexer, please call from a
phone next to your computer, where you can type and read the screen while talking to us.
We will be happy to provide a reasonable level of free support for registered users of the IMX8 Multiplexer.
Reasonable support includes telephone assistance covering the normal installation, use and simple
customization of a computerized system containing an IMX8 Multiplexer connected to a Windows
®
-compatible
computer.
A service contract that extends both the hardware warranty and software update period is available at an
additional charge. Software updates do not include software enhancements offered to our customers at
additional cost.
Enhancements to the IMX8 Multiplexer and Gamry’s standard applications software that require significant
engineering time on our part can be performed on a contract basis. Contact us with your requirements.
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 original shipment date
of your purchase.
Gamry Instruments, Inc. makes no warranties regarding either the satisfactory performance of the IMX8
Multiplexer including the software provided with this product or the fitness of the product 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 system at any time without incurring any
obligation to install same on systems previously purchased. All system 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.

Disclaimers
4
Disclaimers
Gamry Instruments, Inc. cannot guarantee that the IMX8 Multiplexer will work with all computer systems,
operating systems, or third-party hardware/software.
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
IMX8™ Multiplexer Operator’s Manual copyright  2021−2022, Gamry Instruments, Inc., all rights reserved.
Gamry Framework copyright  1989−2022, Gamry Instruments, Inc., all rights reserved.
Interface 1010, Interface 5000, Reference 600+, Reference 620, Reference 3000
TM
, Reference
3000AE
TM
, Reference 30K, LPI1010, eQCM 10M, ECM8, Gamry Framework, Faraday Shield, and
Gamry are trademarks of Gamry Instruments, Inc.
Windows
®
is a registered 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.

Table of Contents
5
Table of Contents
If You Have Problems ..................................................................................................................................... 3
Limited Warranty ............................................................................................................................................ 3
Disclaimers ..................................................................................................................................................... 4
Copyrights ...................................................................................................................................................... 4
Table of Contents ............................................................................................................................................ 5
Chapter 1: Safety Considerations .................................................................................................................... 7
Inspection ............................................................................................................................................... 7
Product Safety ......................................................................................................................................... 7
AC Mains Connection to the Power Brick ................................................................................................ 8
Grounding in the IMX8 Multiplexer ......................................................................................................... 8
Functional Grounding and Product Safety ................................................................................................ 9
Temperature and Ventilation ................................................................................................................. 10
Defects and Abnormal Stresses .............................................................................................................. 10
Environmental Limits ............................................................................................................................. 10
Cleaning ............................................................................................................................................... 11
Service .................................................................................................................................................. 11
RF Warning ........................................................................................................................................... 11
Electrical Transient Sensitivity ................................................................................................................ 11
CE Compliance ..................................................................................................................................... 12
RoHS Compliance ................................................................................................................................. 12
Chapter 2: Introduction ................................................................................................................................ 13
About this Manual ................................................................................................................................. 13
About the IMX8 Multiplexer .................................................................................................................. 13
Operation Overview ............................................................................................................................. 13
Keyword Definitions .............................................................................................................................. 15
Switching and Inactive Cell Control ....................................................................................................... 15
Notational Conventions ......................................................................................................................... 17
Chapter 3: Installation ................................................................................................................................... 19
Initial Visual Inspection ......................................................................................................................... 19
Physical Location .................................................................................................................................. 19
Quick-start Guide for System Installation ............................................................................................... 20
Connection to Gamry Instruments Reference 600+ or 620 and Interface 1000 or 1010 potentiostats .... 20
Connection to a Third-party Potentiostat/Galvanostat ............................................................................. 20
Cell Cable Installation ............................................................................................................................ 20
Computer Requirements ....................................................................................................................... 21
Software Installation .............................................................................................................................. 21
Reboot your Computer after Software Installation .................................................................................. 21
USB Cables ........................................................................................................................................... 22
Front Panel USB LED ............................................................................................................................ 22
First-time Device Installation in Windows
®
............................................................................................ 23
Running the Framework ................................................................................................................ 23
Framework Device Status Bar ........................................................................................................ 23
Gamry Instrument Manager ........................................................................................................... 24
Firmware Update .......................................................................................................................... 25
Auto Update All ............................................................................................................................ 26
Select And Update ........................................................................................................................ 26
Pairing your IMX8 Multiplexer ....................................................................................................... 26
Test the Communications and Run Your Experiment .............................................................................. 29

Table of Contents
6
Appendix A: IMX8 Multiplexer Specifications ................................................................................................ 33
Channel Characteristics ......................................................................................................................... 33
Channel Isolation .................................................................................................................................. 33
Local potentiostat .................................................................................................................................. 33
Power Input .......................................................................................................................................... 34
Environmental ....................................................................................................................................... 34
Appendix B: I/O Connections for the IMX8 ................................................................................................... 35
Cell Cable Connector ............................................................................................................................ 35
Normal Cell Cable Connections ............................................................................................................ 36
Potentiostat Connector .......................................................................................................................... 37
Connecting the IMX8 to Third-party Potentiostats .................................................................................. 38
Appendix C: Certifications ............................................................................................................................ 39
Declaration of Conformity: No. DOC-2022-CE-IMX8 ............................................................................ 39
Certificate of Conformance ................................................................................................................... 40
Declaration of Conformity: No. DOC-2022-UKCA-IMX8 ....................................................................... 41
Appendix D: Comprehensive Index .............................................................................................................. 43

Safety Considerations
7
Chapter 1: Safety Considerations
Your IMX8 Multiplexer is supplied in a safe condition. This chapter of the IMX8 Operator’s Manual contains
some information and warnings that you must follow to insure continued safe operation of the IMX8.
Table 1-1
Safety Symbol Definitions
Symbol Description
General Warning sign;
Read throughout manual for all instances
Warning symbol;
Risk of electric shock
Warning symbol;
Observe humidity and water ingress requirements
Inspection
When you receive your IMX8 Multiplexer, inspect it for evidence of shipping damage. If you note any damage,
please notify Gamry Instruments Inc. and the shipping carrier immediately. Save the shipping container for
possible inspection by the carrier.
Product Safety
The IMX8 Multiplexer has been designed, tested, and certified to meet the requirements of EN 61010, Safety
requirements for electrical equipment for measurement, control, and laboratory use. The IMX8 Multiplexer
circuitry is at voltages low enough to be considered safe.
The IMX8 Multiplexer ’s circuitry does not contain voltages higher than 48 V DC. As a generalization, input and
output voltages in the IMX8 Multiplexer are limited to 24 V. This voltage level is considered safe.
The “AC Adapter” supplied with the IMX8 Multiplexer is certified under EN 60950. The AC Adapter converts
the AC mains voltage to 48 V DC, which is used to power the IMX8 Multiplexer.
Always use the AC adapter (power brick) supplied with your IMX8 Multiplexer to power the IMX8. One
exception to this rule; power supplied by a Gamry IPH Interface Power Hub is also allowed.
Warning:
An IMX8 Multiplexer damaged in shipment can be a safety hazard. Do not
operate damaged apparatus until a qualified service technician has verified its safety. Tag a damaged IMX8
Multiplexer to indicate that it could be a safety hazard.

Safety Considerations
8
AC Mains Connection to the Power Brick
The IMX8 Multiplexer does not connect directly to an AC Mains supply. Instead, the mains are connected to
desktop AC adapter (power brick), which outputs 48 V DC, which in turn powers the IMX8 Multiplexer.
The IMX8 Multiplexer is normally provided with an AC line cord suitable for your location. This AC line cord
connects the AC mains to the AC power adapter. If your IMX8 Multiplexer has been provided without an AC
line cord, or a cord that is not compatible with your local AC mains socket, obtain a line cord certified for use
in your country. Contact your local Gamry Representative or e-mail to [e-mail] if you are
uncertain what AC line cord to use.
Grounding in the IMX8 Multiplexer
Most of the IMX8 Multiplexer’s circuitry and its metal case are connected to earth ground via the AC adapter.
The cell connections to the Active cell can be isolated from earth ground if the System Potentiostat is isolated
from earth. Inactive cells that are Open (not in the Shorted or Local Potentiostat modes) will also be isolated
from earth ground.
Most electrochemical cells are isolated from earth ground, so isolation of the IMX8 Multiplexer and System
Potentiostat from earth is not required. In these cases, connection of the System Potentiostat chassis to an earth
ground may lower the noise seen in an electrochemical test. A Chassis Ground banana jack on the rear panel
of the System Potentiostat easily implements this connection. Simply run a wire from this binding post to a
suitable source of earth ground. The black 1.2-meter wire usually provided with Gamry Potentiostats facilitates
this connection.
This connection of the System potentiostat to an earth ground is not a “Protective Earth Ground” as defined in
EN 61010. The IMX8 Multiplexer is safe in the absence of this connection.
Sources of earth ground include:
 Most metal water pipes,
 the chassis of most electronic apparatus (which are generally earth-grounded), and
 the earth ground terminal of an AC mains power plug.
We recommend that you discuss grounding with an electrical or electronics professional prior to making
this earth-ground connection.
The IMX8 Multiplexer’s AC Adapter is rated for operation from 100 to 240 V AC, 47 to
63 Hz. It should therefore be useful throughout the world.
Warning: Use only Gamry-approved DC power sources with your IMX8 Multiplexer. Other
power sources may alter the performance and/or safety characteristics of the IMX8 Multiplexer.

Safety Considerations
9
This binding post is not intended for any use other than connecting the System Potentiostat to a functional
earth ground to improve shielding against noise. Connecting this binding post to a hazardous voltage can create
a significant safety hazard.
Functional Grounding and Product Safety
As defined in IEC Publication 348, Safety Requirements for Electronic Measuring Apparatus, the IMX8 is a
Class I grounded device.
When you use the IMX8 with an approved line cord, the connection to the functional earth ground is
automatically made prior to making any power connections. The USB connection can also sometimes connect
the IMX8 to functional ground if the computer is earth grounded.
The IMX8 is supplied with a line cord suitable for use in the United States. In other countries, you may have to
replace the line cord with one suitable for your type of electrical outlet. You must always use a line cord with a
CEE 22 Standard V female connector on the instrument end of the cable. This is the same connector used on
the US standard line cord supplied with your IMX8.
The wiring polarity of a properly wired connector is shown in Table 1-2 for both US line cords and European
line cords that follow the “harmonized” wiring convention.
Warning:
Do not earth ground the System Potentiostat if your electrochemical cell has
earth ground. This is especially dangerous if the cell can source significant power (e.g., a battery, fuel cell,
or capacitor). The cell can discharge through the IMX8 and/or System Potentiostat, possibly causing severe
damage to the IMX8 or System Potentiostat.
Warning:
If you replace the line cord, you must use a line cord with the same polarity as
that supplied with the IMX8. An improper line cord can create a safety hazard, which could result in
personal injury or death.
Warning:
Do not negate the protection of the IMX8’s earth ground by any means. Do not
use the IMX8 with a two-wire extension cord, with an adapter that does not provide for earth grounding, or
with an electrical outlet that is not properly wired with an earth ground. If the earth ground is not properly
connected, it creates a safety hazard, which could result in personal injury or death.

Safety Considerations
10
Table 1-2
Line Cord Polarities and Colors
Area Line Neutral Earth Ground
USA Black White Green
Europe Brown Light Blue Green/Yellow
If you have any doubts about the line cord for use with your IMX8, please contact a qualified electrician or
instrument service technician for assistance. He or she can perform a simple continuity check that can verify
the connection of the IMX8 chassis to earth and thereby check the safety of your IMX8 installation.
Temperature and Ventilation
Your IMX8 Multiplexer was designed to operate at ambient temperatures between 0°C and 40°C.
Defects and Abnormal Stresses
Treat your IMX8 Multiplexer as potentially hazardous if any of the following is true of the unit:
 It shows visible damage,
 It does not operate properly,
 It has been stored for a long period of time under unfavorable conditions,
 It has been dropped or subjected to severe transport stress,
 It has been subjected to environmental stress (corrosive atmosphere, fire, etc.).
Do not use your IMX8 Multiplexer or any other apparatus if you think it could be hazardous. Have it checked
by qualified service personnel.
Environmental Limits
There are environmental-limit conditions on the storage, shipping, and operation of this equipment. The IMX8
Multiplexer is not designed for outdoor use.
Storage
Ambient Tem
perature
−20C to 60C
Relative Humidity
Maximum 90% non
-
condensing
Shipping
Same as storage plus
Acceleration
Maximum 30 G
Operation
Ambient Temperature
0C to 40C
Relative Humidity
Maximum 90% non
-
cond
ensin
g
Caution:
Be careful when operating the IMX8 in an enclosed space. The temperature
within the enclosure must not exceed 40°C. You may need to provide ventilation holes or even forced air
cooling for the enclosure if the temperature rises excessively.

Safety Considerations
11
Cleaning
Disconnect the IMX8 Multiplexer from all power sources prior to cleaning.
Use a cloth lightly dampened with either clean water or water containing a mild detergent to clean the outside
of the IMX8 Multiplexer enclosure. Alternatively, you can use isopropyl alcohol. Do not use a wet rag or allow
fluid to enter the IMX8 Multiplexer enclosure. Do not immerse the IMX8 Multiplexer in any type of cleaning
fluid (including water). Do not use any abrasive cleaners.
Service
Your IMX8 Multiplexer has no user-serviceable parts inside. Refer all service to a qualified service technician.
RF Warning
Your IMX8 Multiplexer generates, uses, and can radiate radio-frequency energy. The radiated levels are low
enough that the IMX8 Multiplexer should not create an interference problem in most industrial laboratory
environments. The IMX8 is likely to cause radio-frequency interference if operated in a residential
environment.
Electrical Transient Sensitivity
Your IMX8 Multiplexer was designed to offer reasonable immunity from electrical transients. However, in
severe cases, the IMX8 could malfunction or even suffer damage from electrical transients. If you are having
problems in this regard, the following steps may help:
If the problem is static electricity (sparks are apparent when you touch the IMX8):
 Placing your IMX8 on a static-control work surface may help. Static-control work surfaces are now
generally available from computer-supply houses and electronics-tool suppliers. An antistatic floor mat
may also help, particularly if a carpet is involved in generating the static electricity.
 Air ionizers or even simple air humidifiers can reduce the voltage available in static discharges.
If the problem is AC power-line transients (often from large electrical motors near the IMX8):
 Try plugging your IMX8 into a different AC-power branch circuit.
 Plug your IMX8 into a power-line surge suppressor. Inexpensive surge suppressors are now generally
available because of their use with computer equipment.
Warning:
Never operate the IMX8 Multiplexer with any cover or panel on the chassis
open. Dangerous voltages may be present at several points within the IMX8 Multiplexer chassis, including
PC board traces. Always remove the power connection before opening the IMX8 Multiplexer case.
Warning:
The IMX8 Multiplexer is not designed for operation in conditions where liquid
water may enter the chassis, or water vapor may condense within the chassis. Operation of a IMX8
Multiplexer that has water within the chassis can create a safety hazard, which could result in personal
injury or death.

Safety Considerations
12
Contact Gamry Instruments, Inc. if these measures do not solve the problem.
CE Compliance
The European Community has instituted standards limiting radio-frequency interference from electronic
devices and mandating several safety requirements. Gamry Instruments, Inc. has modified its instruments,
including the IMX8, to comply with these standards.
The relevant CE regulations include EN 61010.
RoHS Compliance
The IMX8 Multiplexer has been built using lead-free components and lead-free solder. It is in compliance with
the European RoHS initiative.

Introduction
13
Chapter 2: Introduction
About this Manual
This manual covers the installation, safety, and use of the Gamry Instruments IMX8 Multiplexer.
This manual describes use of an IMX8 Multiplexer with Revision 7.9 (and later revisions) of the Gamry
Framework software. It is equally useful when setting up a newly purchased instrument or modifying the setup
of an older instrument for use with new software.
You will find dry technical material such as specifications and connector pin-out diagrams in the Appendices.
This manual does not discuss software installation or software operation in any detail. Software support for the
IMX8 Multiplexer is described in the Gamry Framework’s Help system.
All the Gamry Instruments’ applications running under the Gamry Framework control the IMX8 Multiplexer via
an IMX object. See the Framework’s Help system for information concerning IMX objects and their functions.
About the IMX8 Multiplexer
The IMX8 Multiplexer was developed to increase the throughput of your electrochemical testing program. It
allows one potentiostat/galvanostat/ZRA to drive up to eight electrochemical cells. Under the control of an
external computer, the IMX8 connects one cell at a time to the potentiostat, which makes an electrochemical
measurement on that cell.
The IMX8 was specially designed for the needs of electrochemists. Extra features such as sense line and shield-
switching, and control of inactive cells separate the IMX8 – designed specifically for electrochemists – from
other general-purpose switching devices.
The IMX8 has been integrated into Gamry Instruments’ electrochemical applications relevant to the IMX8 that
run under the Gamry Framework. It allows many of the DC Corrosion measurement applications to increase
their throughput by testing multiple cells in a single test run. In this system a sophisticated Microsoft
Windows
®
-program is used to control both the IMX8 and a Gamry Instruments potentiostat.
However, the IMX8 is not restricted to use in corrosion testing or use with Gamry Instruments hardware or
software. It was designed to work with other potentiostats , including those sourcing as much as 1.5 amperes of
current. Refer to Gamry Instruments’ Echem Toolkit
TM
for use with 3
rd
part potentiostats.
This chapter of the IMX8 Operator’s Manual provides an overview of the operation of the IMX8. It discusses
the following topics:
 Operation overview
 Switching and inactive cell control
The material in this chapter is only an overview. If you are using your IMX8 Multiplexer with Gamry
Instruments software, this overview should give you sufficient understanding to make intelligent use of your
IMX8.
Operation Overview
Figure 2-1 shows a “typical” electrochemical test system built around an IMX8 Multiplexer. Up to eight cells
can be connected simultaneously to an IMX8. The label on the block marked as a potentiostat is slightly
misleading. Most potentiostats can also be used as a galvanostat or as a ZRA (zero-resistance ammeter) in an
IMX8 system.
In the description of this figure, keywords are in bold type and are defined in the next section.

Introduction
14
Figure 2-1
Typical Electrochemical Test System Using an IMX8 Multiplexer
The system computer is a critical component of the system. It controls the IMX8 by sending it simple
commands through a USB connection.
The most important function of these commands is to select which cell is active (connected to the system
potentiostat). You can think of an IMX8 as a complex switch. One of the eight cell cables on the IMX8 is
switched so that it connects to the potentiostat’s cell cable. All of the wires (including sense leads and shields) in
the cell cable are switched. Other commands select the IMX8’s control mode for the cells that are inactive (not
presently connected to the potentiostat).
The system computer also controls the system potentiostat. Most modern potentiostats generate digital
signals. Primarily, a standard USB connection is used to digitally control these potentiostats. In the case of
analog potentiostats, analog signals from a D/A and A/D computer interface can be sent. When a cell is
connected to the system potentiostat cell leads, the computer causes a test to be run on that cell. The test can
be as simple as a single current or potential measurement or as complex as a cyclic scan or acquisition of an EIS
spectrum. The computer software and system potentiostat are responsible for taking the measurement and
storing it.
The system potentiostat in Figure 2-1 is shown as a “black box”. The IMX8 is designed to work with virtually
any potentiostat. The relays in the IMX8 can carry currents up to 1.5 A, allowing use of the IMX8 with most
high-performance potentiostats.
In a typical IMX8 experiment, the system computer cycles through the cells. Each cell is connected in turn to
the system potentiostat and used to collect a measurement. Usually, the computer delays at the end of each
cycle through the cells so that the measurements on each cell are separated by a fixed time period.

Introduction
15
Keyword Definitions
The following key terms are used throughout this manual.
 Active Cell
The active cell is the cell (if any) currently connected to the system potentiostat. Any electrochemical
measurements are made on the active cell.
 Cell
The term cell is used to describe either an electrochemical cell or the switches needed to connect an
electrochemical cell to the system potentiostat.
 Channel
An IMX8 contains eight channels. A channel includes cell-switching, a local potentiostat and a D/A
converter. The term cell is used when only the cell-switching portion of a channel is being discussed.
 Inactive Cell
The term inactive cell is any cell not currently connected to the system potentiostat. Inactive is a
slightly misleading term since an inactive cell can actually be potentiostated by the IMX8’s local
potentiostat on that channel. An inactive cell can be also shorted to mimic an active cell in ZRA mode.
 Inactive Mode
Inactive cells can be open, connected to a local potentiostat, or shorted. The term inactive mode
describes this choice of control mode for inactive cells.
 Local Potentiostat
A simple low-current potentiostat that maintains potential control on inactive cells. Unlike the system
potentiostat, the local potentiostat is incapable of making electrochemical measurements.
 System Computer
The computer responsible for coordinating operation of an IMX8-based electrochemical test system,
not to be confused with the simple micro-controller buried within the IMX8.
 System Potentiostat
This is the potentiostat responsible for making electrochemical measurements on the cells used in the
experiment. The system potentiostat is typically a full-featured, computer-controlled instrument.
Switching and Inactive Cell Control
In the Operation Overview, we said you can think of the IMX8 as a complex switch. This section of the manual
describes the IMX8-switching in some detail. In addition, control modes for inactive cells are discussed.
Each of the eight IMX8 channels is made up of an independent set of switches and control circuits. Figure 2-2 is
a simplified schematic diagram for one channel of the IMX8. Switches connected with dotted lines are always
switched together and are therefore treated as one multi-pole switch. All the switches are under control of the
system computer. Shield relays are not shown.

Introduction
16
Figure 2-2
Simplified Schematic of a Single IMX8 Channel
The cell cable from the system potentiostat is connected at the left side of the schematic. The system-
potentiostat cell cable can be connected to any of the IMX8 channels. The system computer must ensure that
only one cell at a time is connected to the system potentiostat.
Switch S1 controls which cell is active. S3 and S4 control the inactive mode of the cell on this channel.
Looking at the schematic, you can see that switch S1 connects this channel’s cell to the system potentiostat. An
active channel always has S3 and S4 open. The relays in S1 are rated to carry 1.5 A and switch 500 mA. You
can normally use the IMX8 with potentiostats rated at up to 100 V of output compliance and 1.5 A of output
current.
To avoid transients, Gamry’s software always turns off the cell at the system potentiostat prior to switching S1.
The IMX8 switches all its relays nearly simultaneously (even those in different channels), but there is still about
1 millisecond in which the relay pattern in the IMX8 is in neither the initial or final configuration. Switching
transients as the IMX8 switches channels with a “live” potentiostat can be particularly severe because the
system potentiostat’s feedback goes through one of the S1 relays. To avoid the problem, turn off the cell at the
system potentiostat before switching channels.
You have a choice of three different control schemes for inactive cells. These are tabulated in Table 2-1 along
with the active mode.

Introduction
17
Table 2-1
IMX8 Control Modes
Mode Switch S1 Switch S3 Switch S4
Active Closed Open Open
Open Open Open Open
Local Potentiostat Open Closed Open
Shorted Open Open Closed
The inactive control mode labeled “open” is the simplest. In this mode the cell is disconnected and isolated
from both the system potentiostat and the IMX8. No cell current can flow between any electrodes. This is the
most common inactive mode in corrosion studies, where the cell behavior at open circuit is of interest.
The inactive control mode labeled “local potentiostat” is used to maintain potential control between readings
made with the system potentiostat. If you know something about operational amplifiers and potentiostats, you
may recognize that the operational amplifier in Figure 2-2 is wired as a simple potentiostat. With S3 closed, the
working electrode is connected to the ground on the IMX8 circuit board and the counter electrode is
connected to the output of an operational amplifier. The feedback for this amplifier is taken from the cell’s
reference electrode. This mode can be used whenever it is important to maintain potential control between
readings. One experimental example is tests on amperometric chemical sensors.
Unlike a typical system potentiostat, the local potentiostat is very limited in capability. The amplifier in this local
potentiostat is not a large power amplifier. Its output is typically capable of generating ±30 mA at up to ±10 V.
The local potentiostat has no cell switch other than S3, and it cannot measure current.
The cell can be potentiostated at a voltage that is set via the D/A converter seen in Figure 2-2. This is a 16-bit
converter operating at a resolution of 152.59 µV per bit. The maximum voltage available is ±4.9 V.
The final inactive mode is label “shorted” in Table 2-1. In this mode a relay shorts the working and counter
electrodes. This mode was added so that the IMX8 could be used in galvanic corrosion studies. In a galvanic
corrosion experiment, the current flow between two electrically connected metals is measured. The device that
makes this measurement is called a zero-resistance ammeter (ZRA) .
In the shorted inactive mode the two metals are connected, even when the system ZRA is measuring other
channels.
Both the local potentiostat and shorted mode have voltage inaccuracies caused by the cell current. The working
electrode is nominally at zero volts versus earth ground. When cell current is present, resistance in relays, wires,
and connectors causes the voltage to differ from zero. In the shorted mode the counter lead also has resistance
that contributes voltage error. With a 1.5 m Gamry Instruments cell cable, the resistance in each cell lead
should be less than 0.2 Ω. At 30 mA of current, the voltage error in the local potentiostat mode can be as large
as 6 mV. In the shorted mode and at the same current, the total voltage error can be 12 mV.
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:
Caution:
You can damage the local potentiostat’s amplifier if the reference electrode
potential exceeds ±24 V versus the IMX8 chassis.

Introduction
18
 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 are
capitalized and placed within quotes, for example: “C:\MYGAMRYDATA\CV.DTA” and “GAMRY.INI”.

Installation
19
Chapter 3: Installation
This chapter of the IMX8 Multiplexer Operator’s Manual covers normal installation of the IMX8. Both
installation as part of a Gamry Framework-based electrochemical-measurement system and installation as a
component in a user-configured system are discussed.
These instructions assume use with Gamry’s Framework Software Revision 7.9 or higher.
Figure 3-1
Front View of an IMX8 Multiplexer
Initial Visual Inspection
After you remove your IMX8 Multiplexer from its shipping carton, check it for any signs of shipping damage. If
you find any damage, please notify Gamry Instruments, Inc., and the shipping carrier immediately. Save the
shipping container for possible inspection by the carrier.
Physical Location
Place your IMX8 Multiplexer on a flat workbench surface. You need access to the rear of the instrument
because some cable connections are made from the rear. The IMX8 is not restricted to operation in a
horizontal position. You can operate it on its side, or even upside-down.
Caution:
An IMX8 damaged in shipment can be a safety hazard. Do not operate a
damaged apparatus until a qualified service technician has verified its safety. Tag a damaged IMX8 to
indicate that it could be a safety hazard.
Caution:
The IMX8 has an internal fan which distributes the heat generated by the IMX8
circuitry to the metal chassis. Blocking heat transfer from the chassis to the environment could cause IMX8
overheating.

Installation
20
If you place your IMX8 Multiplexer within an enclosed space, make sure that the temperature within that space
does not exceed the 40C ambient temperature limit of the IMX8. Be particularly careful if a computer or other
heat-dissipating equipment is mounted in the same enclosure as the IMX8.
The IMX8 Multiplexer has not been designed for outdoor use.
Quick-start Guide for System Installation
Your shipment includes a short document entitled Quick-start Installation Guide–USB Potentiostat. It contains
the latest instructions for installing Gamry hardware and software onto a computer system. If this document is
missing, the following information should be sufficient for you to install the Gamry Framework Software and
Gamry potentiostat onto your computer.
Connection to Gamry Instruments Reference 600+ or 620 and Interface
1000 or 1010 potentiostats
Connection of your IMX8 to a Gamry Instruments Reference 600+ or 620 and Interface 1000 or 1010
potentiostat respectively is quite simple. Gamry Instruments supplies a standard cable (part number 985-00080)
that properly connects the cell wires. This 1.5 m cable is equipped with a male 9-pin D-connector on the IMX8
end and a male 25-pin D-connector on the Reference 600+ or 620 and Interface 1000 or 1010 end.
The Reference 600+ or 620 and Interface 1000 or 1010 can identify the cable plugged into its cell connector.
It detects the presence of an IMX8 Multiplexer in your system. The Reference 600+ or 620 and Interface 1000
or 1010 cannot identify the cables used to connect the eight individual cells to the IMX8.
EIS performance with an IMX8 and a Reference 600+ or 620 and Interface 1000 or 1010 is optimal when all
the cell cables are 1.5 m cables. All other cables may create errors in phase and magnitude.
Connection to a Third-party Potentiostat/Galvanostat
Connecting the IMX8 to a third-party potentiostat/galvanostat is more of a problem: You have to build a custom
cable. See Appendix C of this manual for the pin-layout of the IMX8 Potentiostat connector and for hints on
cable construction. We strongly recommend that you contact us prior to constructing the cable.
Cell Cable Installation
Each cell to be tested in an experimental run requires a cell cable.
When you are using the IMX8 with a Gamry Instruments potentiostat, Cell Cable connections to the cell are
made in the manner described in the potentiostat’s Operator’s Manual. Cell connections when the IMX8 is
used with a third-party potentiostat may not follow the normal Gamry conventions, so you should contact
Gamry Instruments to obtain special instructions if this is your situation.
Your IMX8 Multiplexer comes with eight 1.5 m long cell cables with a male 9-pin D-connector on the IMX8
end. The other end of the cable has banana-plug/alligator-clip termination to connect to a cell. Longer cables as
well as specialized cables are also available, including cables designed for connection to standard three-
terminal corrosion-monitoring probes. Contact support for more information.
Caution:
Never substitute a generic 25-to-9-pin cable designed for computer
interconnection for this cable. Gamry Instruments’ cable includes individual shielding for several signals in
this cable. Use of a generic cable is likely to create excessive noise and system oscillation.