Gamry Instruments Reference 3000 User manual

Reference 3000™
Potentiostat/Galvanostat/ZRA
Operator’s Manual
Copyright  2012–2021 Gamry Instruments, Inc.
Revision 6.4
August 18, 2021
988-00014

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 a Reference 3000, 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 Reference 3000
Potentiostat/Galvanostat/ZRA. Reasonable support includes telephone assistance covering the normal
installation, use and simple customization of a computerized system containing a Reference 3000 connected to
a Windows
®
7 or higher 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 Reference 3000 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 Reference
3000 Potentiostat/Galvanostat/ZRA 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 Reference 3000 Potentiostat/Galvanostat/ZRA will work with
all computer systems, operating systems, or third-party software applications 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
Reference 3000™ Potentiostat/Galvanostat/ZRA Operator’s Manual copyright  2008−2021, Gamry
Instruments, Inc., all rights reserved.
Gamry Framework copyright  1989−2021, Gamry Instruments, Inc., all rights reserved.
Interface 1010, Interface 5000, 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 .................................................................................................................... 9
Inspection ............................................................................................................................................... 9
Product Safety ......................................................................................................................................... 9
AC Mains Connection to the Power Brick ................................................................................................ 9
Grounding in the Reference 3000 ......................................................................................................... 10
Operation with Earth-Grounded Cells and Auxiliary Apparatus .............................................................. 11
Temperature and Ventilation ................................................................................................................. 12
Defects and Abnormal Stresses .............................................................................................................. 12
Environmental Limits ............................................................................................................................. 12
Cleaning ............................................................................................................................................... 13
Service .................................................................................................................................................. 13
RFI Warning .......................................................................................................................................... 13
Electrical Transient Sensitivity ................................................................................................................ 13
CE Compliance ..................................................................................................................................... 14
RoHS Compliance ................................................................................................................................. 14
Chapter 2: Introduction ................................................................................................................................ 15
About this Manual ................................................................................................................................. 15
About the Reference 3000 .................................................................................................................... 15
About the Auxiliary Electrometer Option ............................................................................................... 16
Notational Conventions ......................................................................................................................... 16
Chapter 3: Instrument Circuitry ..................................................................................................................... 17
Reference 3000 Schematic/Block Diagrams ........................................................................................... 17
Chapter 4: Installation ................................................................................................................................... 27
Initial Visual Inspection ......................................................................................................................... 27
Physical Location .................................................................................................................................. 28
Computer Requirements ....................................................................................................................... 28
Quick-start Guide for System Installation ............................................................................................... 29
Software Installation .............................................................................................................................. 29
Reboot your Computer after Software Installation .................................................................................. 29
Power Cord and Power Connection ...................................................................................................... 30
Power-up Test ....................................................................................................................................... 31
USB Cables ........................................................................................................................................... 31
Front Panel USB LED ............................................................................................................................ 31
First-time Device Installation in Windows® ........................................................................................... 32
Running the Framework ........................................................................................................................ 32
Framework Device Status Bar ................................................................................................................ 32
Gamry Instrument Manager ................................................................................................................... 33
Changing the Label ............................................................................................................................... 34
Firmware Update .................................................................................................................................. 35
Chapter 5: Calibration .................................................................................................................................. 37
Introduction .......................................................................................................................................... 37
DC and AC Calibration ......................................................................................................................... 37

Table of Contents
6
Low I Range DC Calibration .................................................................................................................. 38
Cable Calibration .................................................................................................................................. 39
Procedure to calibrate the cable .................................................................................................... 40
Chapter 6: Cell Connections ......................................................................................................................... 43
Cell Cable Overview ............................................................................................................................. 43
Ancillary Apparatus ....................................................................................................................... 43
AE Connections ............................................................................................................................. 43
Fuses in the Cell Cable .......................................................................................................................... 43
Normal Cell Connections ...................................................................................................................... 43
ZRA Mode Cell Connections ................................................................................................................. 45
Stack Mode Cell Connections ................................................................................................................ 46
Membrane Cell Connections ................................................................................................................. 46
Fuses in the Cell Cable .......................................................................................................................... 47
In-line Fuse-Holders and Fuses ...................................................................................................... 47
Fuses Located in the Cable Hood .................................................................................................. 48
Testing For Open Fuses ................................................................................................................. 50
Chapter 7: Panel Indicators and Connectors .................................................................................................. 53
Front Panel ........................................................................................................................................... 53
Counter/Working Connector ......................................................................................................... 53
Sense Inputs Connector ................................................................................................................. 54
Power LED .................................................................................................................................... 54
USB LED ....................................................................................................................................... 56
Cell On LED .................................................................................................................................. 56
Overload LED ............................................................................................................................... 56
Rear Panel ............................................................................................................................................ 58
Power In Jack ................................................................................................................................ 58
Power Switch ................................................................................................................................ 59
Chassis Ground ............................................................................................................................. 60
USB Port ....................................................................................................................................... 60
Thermocouple Input ..................................................................................................................... 61
Misc. I/O Connector ...................................................................................................................... 61
I Monitor BNC .............................................................................................................................. 62
E Monitor BNC.............................................................................................................................. 63
Ext. Sig. In BNC ............................................................................................................................. 63
Sig Gen. Out BNC ......................................................................................................................... 64
Aux. In BNC .................................................................................................................................. 64
Expansion Interface ....................................................................................................................... 64
Chapter 8: Auxiliary Electrometer Option ...................................................................................................... 65
Overview .............................................................................................................................................. 65
AC Performance and CMRR .................................................................................................................. 65
Experiments .......................................................................................................................................... 66
Connections Using Standard Cables ...................................................................................................... 66
Connections Using Custom Cables ........................................................................................................ 67
AE Specifications ................................................................................................................................... 67
Chapter 9: Stability in Potentiostat Mode ...................................................................................................... 69
Capacitive Cells and Stability ................................................................................................................. 69
Improving Potentiostat Stability ............................................................................................................. 69
Chapter 10: Measurement of Small-current Signals ........................................................................................ 73
Overview .............................................................................................................................................. 73
Description of the Problem ................................................................................................................... 73
Measurement System Model and Physical Limitations ............................................................................ 73
Johnson Noise in Zcell ................................................................................................................... 74

Table of Contents
7
Finite Input Capacitance ................................................................................................................ 75
Leakage Currents and Input Impedance ......................................................................................... 75
Voltage Noise and DC Measurements ............................................................................................ 76
Shunt Resistance and Capacitance ................................................................................................. 76
Hints for System and Cell Design ........................................................................................................... 77
Faraday Shield............................................................................................................................... 77
Avoid External Noise Sources ........................................................................................................ 77
Cell Cable Length and Construction ............................................................................................... 77
Lead Placement ............................................................................................................................ 78
Cell Construction .......................................................................................................................... 78
Reference Electrode ...................................................................................................................... 78
Instrument Settings ........................................................................................................................ 78
EIS Speed ...................................................................................................................................... 79
Ancillary Apparatus ....................................................................................................................... 79
Floating Operation ................................................................................................................................ 79
Chapter 11: EIS Measurement of Small Impedances ...................................................................................... 81
Overview .............................................................................................................................................. 81
Why Galvanostatic Mode? ..................................................................................................................... 81
DC Errors and Four-terminal Measurements .......................................................................................... 81
What is Mutual Inductance? .................................................................................................................. 82
Avoid high frequencies .................................................................................................................. 83
Minimize the Net Magnetic Field ................................................................................................... 83
Separate the pairs .......................................................................................................................... 83
Twist the Sense Wires .................................................................................................................... 84
How Should You Hook Up Your Cell? ................................................................................................... 84
Appendix A: Reference 3000 Specifications .................................................................................................. 85
Control Amplifier .......................................................................................................................... 85
Differential Electrometer................................................................................................................ 85
Voltage Measurement .................................................................................................................... 86
Current-to-Voltage Converter ........................................................................................................ 86
Current Measurement ................................................................................................................... 86
Potentiostatic Mode ...................................................................................................................... 87
Galvanostatic Mode ...................................................................................................................... 87
Auxiliary A/D Input (see Appendix D) ............................................................................................ 87
Auxiliary D/A Output ..................................................................................................................... 87
Environmental ............................................................................................................................... 87
General ......................................................................................................................................... 88
Appendix B: Reference 3000 Cell Connectors ............................................................................................... 91
Appendix C: Misc. I/O Connector ................................................................................................................. 93
Appendix D: Auxiliary A/D Input Characteristics ............................................................................................ 95
Overview .............................................................................................................................................. 95
Jumper Identification ............................................................................................................................. 95
Input Impedance Selection .................................................................................................................... 96
Bandwidth Selection ............................................................................................................................. 96
Aux A/D Specifications .......................................................................................................................... 96
Function Call to Set the Aux A/D BNC Characteristics ............................................................................ 96
Appendix E: Auxiliary Electrometer Specifications .......................................................................................... 97
DC Voltage Measurement ............................................................................................................. 97
Input Impedance ........................................................................................................................... 97
Common Mode Rejection ............................................................................................................. 97
Crosstalk ....................................................................................................................................... 97

Table of Contents
8
Other AC Specifications ................................................................................................................ 97
Appendix F: Power LED Blink Codes ............................................................................................................. 99
Normal Start-up ............................................................................................................................ 99
Failure in an electronics module .................................................................................................... 99
Severe problem ............................................................................................................................. 99
Appendix G: Certifications .......................................................................................................................... 101
Declaration of Conformity: No. DOC-2009-CE-REF3000 .................................................................... 101
Certificate of Conformance ................................................................................................................. 102
Declaration of Conformity: No. DOC-2021-UKCA-REF3000 ............................................................... 103
Appendix H: Comprehensive Index ............................................................................................................ 105

Safety Considerations – Inspection
9
Chapter 1: Safety Considerations
Your Reference 3000 Potentiostat/Galvanostat/ZRA has been supplied in a safe condition. This chapter of the
Reference 3000 Operator’s Manual contains some information and warnings that you must follow to insure
continued safe operation of the Reference 3000.
The safety information in this chapter applies to both the Reference 3000 and the Reference 3000 equipped
with its AE Auxiliary Electrometer.
Inspection
When you receive your Reference 3000 Potentiostat/Galvanostat/ZRA, 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 Reference 3000 has been designed, tested and certified to meet the requirements of an international
standard, EN 61010, Safety requirements for electrical equipment for measurement, control, and laboratory
use. As defined in this standard, it is a Category II apparatus, with any "hazardous live voltages" protected by
“reinforced insulation”.
The Reference 3000 contains a limited amount of internal circuitry that operate at “hazardous live” voltages as
defined in EN 61010 (the standard mentioned above). “Reinforced insulation” (again defined in EN 61010) is
used to reduce the risk of electrical shock because of this “hazardous live” voltage.
The majority of the Reference 3000’s circuitry does not contain voltages higher than 42 V DC. As a
generalization, input and output voltages in the Reference 3000 are limited to 36 V. This voltage level is
considered safe.
The “AC Adapter” supplied with the Reference 3000 is certified under EN 60950. The AC Adapter converts the
AC mains voltage to 24 V DC, which is used to power the Reference 3000.
Always use the AC adapter (power brick) supplied with your Reference 3000 to supply DC power to the
instrument.
AC Mains Connection to the Power Brick
The Reference 3000 does not connect directly to an AC Mains supply. Instead, the mains are connected to the
desktop AC adapter (power brick), which outputs 24 V DC, which in turn powers the Reference 3000.
Caution:
Do not use a DC power source other than the AC adapter model provided with
your Reference 3000. Other replacements may void the performance and/or safety characteristics of the
Reference 3000
.
Warning:
A Reference 3000 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 Reference
3000 to indicate that it could be a safety hazard.

Safety Considerations – Grounding in the Reference 3000
10
The Reference 3000 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 Reference 3000 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 techsupp[email protected]m if you are
uncertain what AC line cord to use.
Grounding in the Reference 3000
The circuitry and the metal case of the Reference 3000 are not connected to an earth ground. If they were
connected to earth ground, it would compromise the Reference 3000’s ability to make measurements in
electrochemical cells that contain earth grounded conductors. A few examples of such cells include autoclaves,
metallographic stress apparatus, chemical storage tanks, and most large fuel-cell stacks.
Most electrochemical cells are isolated from earth ground, so isolation of the Reference 3000 from earth is not
required. In these cases, connection of the Reference 3000 chassis to an earth ground may lower noise seen in
electrochemical tests. A Chassis Ground binding post on the rear panel of the Reference 3000 makes for easy
implementation of this connection. Simply run a wire from this binding post to a suitable source of earth
ground. A black 1.2-meter wire is provided with the Reference 3000 to ease this connection.
Note this connection of the Reference 3000 to an earth ground is not a “Protective Earth Ground” as defined in
EN 61010. The Reference 3000 is safe in the absence of this connection.
This binding post is not intended for any use other than connecting the Reference 3000 to an earth ground to
improve shielding against noise. Connecting this binding post to a hazardous voltage can create a significant
safety hazard.
Warning:
Do not connect the chassis ground binding post to any voltage other than
earth ground. An improper connection can create a safety hazard, which could result in personal injury or
death.
Sources of earth ground include
• Most metal water pipes,
• The chassis of most electronic apparatus (which are generally earth-grounded), and
• The protective 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 Reference 3000’s AC Adapter is rated for operation from 100 to 240 V AC, 47 to 63 Hz.
It should therefore be useful throug
hout the world.

Safety Considerations – Operation with Earth-Grounded Cells and Auxiliary Apparatus
11
An earth ground connection can cause problems when testing batteries, fuel cells, or capacitors. Many of these
devices can source huge currents, often tens or hundreds of amperes. If the Reference 3000 chassis is earth
grounded, and another location in the stack is accidentally (or intentionally) connected to earth ground, a
portion of the stack is shorted through the Reference 3000’s cell cable. Very large current flows when this
occurs. Fuses in the cell cable will open up to prevent damage to the instrument. When this happens, the failed
fuses must be replaced before the instrument can be used again. The fuses in the cell cable are not essential for
operator safety. A section in Chapter 6 describes the fuses and their replacement in detail.
Operation with Earth-Grounded Cells and Auxiliary Apparatus
As described above, the Reference 3000 circuitry is isolated from earth ground, allowing it to make
measurements on cells that include an earth ground. This ground isolation is often called floating operation.
Cells with earth ground include many autoclaves, pipelines and storage tanks, and many fuel-cell systems.
Connection of the Reference 3000 to auxiliary apparatus will often earth-ground the Reference 3000,
destroying its ability to float and make measurements on earth-grounded cells. Connection of the Monitor
BNCs to an oscilloscope is an example where the instrument is earthed.
The User I/O connector can be connected to earth-grounded apparatus without earth-grounding the
Reference 3000, if the cable connections are done carefully. The metal shell on the Reference 3000 User I/O
Connector is connected to the instrument’s chassis, which is a floating ground. In a system that needs isolation
from earth ground, the shield of a User I/O cable must not connect the D-connector’s metal shell to earth
ground. Reference all User I/O signals to pin 6 of the D-connector, which is isolated ground on the Reference
3000.
The Reference 3000 contains surge suppressors that limit the voltage difference between the Reference 3000’s
chassis ground and earth ground to about 40 V. These surge suppressors are not part of the safety mechanisms
in the Reference 3000. Instead, they are present to limit the possibility of improper instrument operation or
instrument damage caused by electrostatic discharge (static electricity) and other surge events such as lightning.
Caution:
Floating operation of the Reference 3000 can be compromised by improper
cables to your I/O Connector. We do not recommend use of standard 15-pin shielded cables with this
connector. Custom cables with the shield connected to pin 6 of the D-connector are preferred.
The fuses in the Reference 3000 cell cable do not protect against a safety hazard. They are
needed to prevent damage to the instrumen
t if it
is improperly connected
.
Warning:
Do not connect the chassis ground binding post to any voltage other than
earth ground. An improper connection can create a safety hazard, which could result in personal injury or
death.

Safety Considerations – Temperature and Ventilation
12
Temperature and Ventilation
Your Reference 3000 Potentiostat/Galvanostat/ZRA was designed for indoor use at ambient temperatures
between 0C and 45C.
The Reference 3000 uses forced air-cooling to keep its electronic components within their recommended
operating temperature range. Three fans on the rear panel of the Reference 3000 draw air into the chassis. The
air exits from slots located on the sides of the chassis near the front panel.
Be careful when operating the Reference 3000 in an enclosed space (such as an enclosed relay rack or NEMA
enclosure). The temperature within the enclosure must not exceed 45C. You may need to provide ventilation
holes or even forced air-cooling for the enclosed space if you determine that there is an excessive temperature
rise within the space.
Defects and Abnormal Stresses
Treat your Reference 3000 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 Reference 3000 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
Reference 3000 is not designed for outdoor use.
Storage
Ambient Tem
perature
−40C to 75C
Relative Humidity
Maximum 90% non
-
condensing
Shipping
Same as storage plus
Acceleration
Maximum 30 G
Operation
Ambient Temperature
0C to 45C
Relative Humidity
Maximum 90% non
-
cond
ensing
Caution:
Do not block the airflow into or out of the Reference 3000 chassis. While the
circuitry should shut down before it is damaged by excessive heat, the Reference 3000 enclosure may
become uncomfortably hot to the touch if insufficient air flows through the chassis. Running the Reference
3000 without adequate cooling could shorten the time to failure of some of the circuitry.

Safety Considerations – Cleaning
13
Cleaning
Disconnect the Reference 3000 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 Reference 3000 enclosure. Alternatively, you can use isopropyl alcohol. Do not use a wet rag or allow
fluid to enter the Reference 3000 enclosure. Do not immerse the Reference 3000 in any type of cleaning fluid
(including water). Do not use any abrasive cleaners.
Service
Your Reference 3000 Potentiostat/Galvanostat/ZRA has no user-serviceable parts inside. Refer all service to a
qualified service technician.
RFI Warning
Your Reference 3000 Potentiostat/Galvanostat/ZRA generates, uses, and can radiate radio-frequency energy.
The radiated levels are low enough that the Reference 3000 should not create an interference problem in most
industrial laboratory environments.
The Reference 3000 has been tested for both radiated and conducted RF interference and has been found to
be in compliance with FCC Part 18 and EN 61326:1998—Electrical equipment for measurement, control, and
laboratory use— EMC Requirements.
Electrical Transient Sensitivity
Your Reference 3000 Potentiostat/Galvanostat/ZRA was designed to offer reasonable immunity from electrical
transients, including transients on the incoming AC Mains supply and Electrostatic Discharge. It has been tested
for compliance with EN 61326:1998—Electrical equipment for measurement, control, and laboratory use—
EMC Requirements describing acceptable limits for Electrical Transient susceptibility in Laboratory Test
equipment. The Reference 3000 is not rated for continuous use when subject to ESD events. It should suffer no
permanent damage when subject to the standard ESD events defined in EN 61326 but may cease normal
operation until it is powered down and restarted.
In severe cases, the Reference 3000 could malfunction as a result of electrical transients such as a static
discharge. 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 Reference 3000 or its cables):
Warning:
Never operate the Reference 3000 with any cover or panel on the chassis
open. Dangerous voltages may be present at several points within the Reference 3000 chassis, including PC
board traces.
Always r
emove the power connecti
on before open
ing the
Reference 3000
case.
Warning:
The Reference 3000 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 Reference
3000 that has water within the chassis can create a safety hazard, which could result in personal injury or
death.

Safety Considerations – CE Compliance
14
 Placing your Reference 3000 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 Reference 3000):
 Try plugging your Reference 3000 into a different AC power branch circuit.
 Plug your Reference into a power-line surge suppressor. Inexpensive surge suppressors designed for
use with computer equipment are now generally available.
Contact Gamry Instruments, Inc. if these measures do not solve the problem.
CE Compliance
The European Community has instituted standards limiting radio-frequency interference emitted by electronic
devices, setting limits for susceptibility of apparatus to RF energy and transient events, and mandating safety
requirements. Gamry Instruments, Inc. has designed and tested the Reference 3000 to comply with these
standards.
The relevant CE regulations include EN 61010 and EN 61326.
RoHS Compliance
The Reference 3000 has been built using lead-free components and lead-free solder. It is in compliance with
the European RoHS initiative.

Introduction – About this Manual
15
Chapter 2: Introduction
About this Manual
This manual covers the installation, safety, and use of the Gamry Instruments Reference 3000
Potentiostat/Galvanostat/ZRA. It also includes information about the Reference 3000’s AE Auxiliary
Electrometer option.
This manual describes use of a Reference 3000 with Revision 7.00 (and later revisions) of the Gamry
Framework software. It is equally useful when setting up a newly purchased potentiostat or modifying the setup
of an older potentiostat 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
Reference 3000 is described in the Gamry Framework’s Help system.
All the Gamry Instruments’ applications running under the Gamry Framework control the Reference 3000 via a
PSTAT object. See the Framework’s Help system for information concerning PSTAT objects and their functions.
About the Reference 3000
The Reference 3000 Potentiostat is a research-grade electrochemical instrument packaged in a small, easy-to-
handle case. It is the larger, higher-current sibling of Gamry’s extremely popular Reference 600+ potentiostat.
It is especially useful when currents higher than the 600 mA current-limit of the Reference 600+ are required.
Typical applications for the Reference 3000 include research regarding batteries, fuel cells and super-
capacitors. It should also prove useful in studies involving electrochemical synthesis, electroplating and
corrosion. While it can apply and measure ampere-level currents, it is also an excellent small-signal potentiostat
that can work with picoampere and sometimes even femtoampere current levels.
The Reference 3000 offers measurement capabilities similar to instruments many times larger in size, weight,
and price. The Reference 3000 can operate as a potentiostat, a galvanostat, or a ZRA (zero-resistance
ammeter). A new stack mode allows precision control and measurement of battery-stack voltages as large as
36 V.
The Reference 3000 offers two different compliance-voltage and compliance-current settings. You can choose
to operate the Reference 3000 set for compliance of 1.5 A and voltages up to 30 V, or you can chose to
operate at 3 A and voltages up to 15 V. This choice cannot be changed in the middle of an experimental
run.
Reference 3000 features include:
 Eleven-decade current auto-ranging,
 Electrical isolation from earth ground,
 Switchable compliance-current and compliance-voltage settings,
 Current-interrupt iR-compensation, and
 Both analog and digital filtering.
A sine-wave generator on the Reference 3000 allows its use for impedance measurements at frequencies up to
1 MHz. Data can be acquired at frequencies up to 300 000 points per second, allowing cyclic voltammetry at
scan rates of 1500 V/s with 5 mV per point resolution.
A unique DSP (Digital Signal Processing) data-acquisition mode allows the Reference 3000 to reject noise from
the instrument itself, from the electrochemical cell, and from the laboratory environment. In many cases where
other instruments require a cell in a Faraday shield to make quiet measurements, the Reference 3000 can be
used with the cell exposed on a bench top.

Introduction – About the Auxiliary Electrometer Option
16
The Reference 3000 offers an unprecedented combination of high speed, high sensitivity, and low noise. State-
of-the-art analog components were used throughout the design. In all design decisions, performance weighed
more heavily than product cost.
The Reference 3000, like all Gamry potentiostats, requires a computer for its use. Unlike most of Gamry’s older
potentiostats, the Reference 3000 connects to the computer through a USB connection. The USB connection
has become truly universal, with USB ports found on all modern computers. Gamry’s software currently
supports up to 16 Reference 3000 Potentiostats connected to one computer.
The Reference 3000 is isolated from earth ground. It can therefore be used to make measurements on cells that
contain an earth-grounded metal. A few of examples of such systems include are autoclaves, large metal
storage tanks, stress apparatus, and capillary electrophoresis detectors.
About the Auxiliary Electrometer Option
The Reference 3000 Potentiostat can be equipped with a unique Auxiliary Electrometer option. This factory-
installed option is especially useful when you need to measure the performance of individual cells in a multi-
cell fuel cell or battery stack.
Up to eight completely independent voltages can be measured using this option. The measurements are fully
differential, so cell voltages at any point in a stack can be measured. Each input can measure a 5 V signal
superimposed on a common-mode voltage that can be as large as  36 V! The input impedance is greater than
10
11
, so the inputs can even be connected to small diameter Luggin probes.
This option can be used to simultaneously measure electrochemical impedance on up to eight cells in a cell
stack. This is often of great interest because cells in a fuel cell or battery stack are not identical.
The AE is not restricted to energy-conversion and -storage applications. The electrometer inputs can measure
virtually any voltage. You can measure voltages from temperature, pressure, or strain transducers or voltages of
multiple reference electrodes in a cell.
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.

Instrument Circuitry – Reference 3000 Schematic/Block Diagrams
17
Chapter 3: Instrument Circuitry
Reference 3000 Schematic/Block Diagrams
If you are not familiar with electronic schematics or potentiostats, you probably want to skip this chapter. This
information is for expert use only and is not required for routine use of the Reference 3000.
The following figures are partly schematic diagrams and partly block diagrams. They are intended to show the
basic principles of the Reference 3000 circuitry without the confusion of the full circuitry details. The
complexity of the Reference 3000 can be quite daunting: the Reference 3000 circuit boards contain more than
3000 components connected by almost 2500 circuit nets!
The schematic/block diagram figures show:
 The potentiostat board and heat sink board in a potentiostatic control mode,
 The control board circuits for signal generation,
 The control board circuits for signal conditioning and A/D conversion,
 The Auxiliary ADC channel input switching,
 The microprocessors in the Reference 3000,
 DC-DC power conversion,
 The optional Multi Channel (MCE) circuitry.

Instrument Circuitry – Reference 3000 Schematic/Block Diagrams
18
Figure 3-1
Reference 3000 Potentiostat Board in Potentiostat Mode
Simplified Schematic/Block Diagram

Instrument Circuitry – Reference 3000 Schematic/Block Diagrams
19
Notes for Figure 3-1:
 The 4× booster following the Control Amp can operate with two combinations of compliance current
and compliance voltage. One is 1.5 A at 30 V, the other is 3 A at 15 V.
 Only Potentiostat Mode circuitry is shown in this figure. In this mode the voltage difference between
the Reference and Working Sense leads (called Esig) is feedback into the control amplifier.
In Galvanostat Mode, the feedback is from Isig.
In the ZRA and stack modes, the feedback is from a differential amplifier measuring the difference
between the Counter Sense and Working Sense leads of the cell cable. The counter sense circuitry is
not shown. It is conceptually similar to the voltage-sensing circuit that generates Esig, except that it can
measure voltage differences as large as  36 V.
 The Bias DAC and PFIR (Positive Feedback IR-compensation) DAC are set using a computer bus that is
not shown.
 Switches are either reed relays or MOS switches as appropriate. All switches are under computer
control (obviously, for the Reference 3000 does not have a knob-and-dial front panel).
 The variable current-measurement resistor, Rm, is one of eleven fixed-value resistors selected using
relays. The resistor’s values vary by decades: 50 m, 500 m, 5, 50  …500 M. The lower-value
resistors require software-gain corrections. Correction values are measured at Gamry’s test facility and
stored in an EEPROM on the Reference 3000 potentiostat board. Software calibration of the
instrument by a customer does not change these Rm gain corrections.
 Other components shown as being variable (IEStab capacitor and CASpeed capacitor) are actually
several fixed-value components switched into the circuit, and not continuously variable.
 The monitor BNC connectors for Isig and Esig are lightly filtered using an RLC circuit.
 The ADC channel for Esig is actually switchable between Esig (the reference voltage minus the working
sense voltage) and Zsig (the counter sense voltage minus the working sense voltage). The Zsig
connection allows the Reference 3000 to measure the voltage of battery or fuel-cell stacks.
 The programmable attenuator on Esig prior to the ADC channel scales the Esig voltage to make it
compatible with the A/D channel’s 3 V input range. The 0.25 gain setting allows the Reference 3000
to measure potential signals slightly in excess of 10 volts (on a 12-volt full-scale range). Isig is gained to
be 3 V full-scale so it does not require a similar attenuation function.
 All the resistors summing voltages into the Control Amplifier input do not have values shown on the
diagram; their values depend on scaling factors too complex to discuss in this chapter.
 Calibration components are not shown.
 Gamry’s software can disconnect the signal generator from the Potentiostat. Once disconnected it can
be used for other experimental-control tasks.
 Overload protection and overload detection are not shown. Good engineering practice demands that
any possible misconnection of the cell leads will not damage the instrument. This practice has been
followed in the Reference 3000 design.
The overload protection can handle overloads of up to 30 A for very short times. Fuses in the Working
and Counter Sense leads always open up before overload conditions can damage the instrument.
Misconnection of a battery, fuel cell, or super-capacitor stack can open the fuse, but will not cause
hardware failures.

Instrument Circuitry – Reference 3000 Schematic/Block Diagrams
20
Figure 3-2
Reference 3000 Signal-Generation Circuitry
Notes for Figure 3-2:
 All the resistors summing voltages into the Summing Amplifier input do not have values shown on the
diagram. Their values depend on scaling factors too complex for this simplified diagram.
 The IR DAC has a 8 V full-scale range.
 Calibration components are not shown.
 The DDS can generate fixed-amplitude sine waves with frequencies between 1 MHz and 1 mHz. In
practice, Gamry’s electrochemical-impedance spectroscopy software uses the Scan DAC to generate
sine signals if the frequency is below 1 Hz.
The low-pass filter removes high-frequency distortion in the “raw” DDS output.
The attenuator scales the DDS. The maximum output signal is 5.979 V peak-to-peak, and the
minimum is approximately 11 V peak-to-peak.
 The BNC connector for Sig Gen out is lightly filtered using an RLC circuit.