Tektronix KEITHLEY 2450-EC User Manual
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Tektronix KEITHLEY 2450-EC User Manual

Tektronix KEITHLEY 2450-EC User Manual

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Model 2450-EC and 2460-EC
Electrochemistry Lab Systems
User's Manual
077110401 / December 2015
*P071110401*
071110401
A Greater M easure of Confidence
A T ektronix Company
www.oitek.com.cn

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  • Page 1 www.tek.com/keithley Model 2450-EC and 2460-EC Electrochemistry Lab Systems User’s Manual 077110401 / December 2015 *P071110401* 071110401 A Greater M easure of Confidence A T ektronix Company www.oitek.com.cn...
  • Page 2 Model 2450-EC and 2460-EC Electrochemistry Lab Systems User's Manual © 2015, Keithley Instruments Cleveland, Ohio, U.S.A. All rights reserved. Any unauthorized reproduction, photocopy, or use of the information herein, in whole or in part, without the prior written approval of Keithley Instruments is strictly prohibited. All Keithley Instruments product names are trademarks or registered trademarks of Keithley Instruments.
  • Page 3 Safety precautions The following safety precautions should be observed before using this product and any associated instrumentation. Although some instruments and accessories would normally be used with nonhazardous voltages, there are situations where hazardous conditions may be present. This product is intended for use by qualified personnel who recognize shock hazards and are familiar with the safety precautions required to avoid possible injury.
  • Page 4 accessories are used in a manner not specified in the operating instructions, the protection provided by the equipment may be impaired. Do not exceed the maximum signal levels of the instruments and accessories, as defined in the specifications and operating information, and as shown on the instrument or test fixture panels, or switching card.

  • Page 5: Table Of Contents

    Table of Contents Model 2450-EC and 2460-EC User's Manual ............1-1 Introduction .......................... 1-1 Cyclic voltammetry ....................... 1-3 Simplified cyclic voltammetry basics ..................1-4 Device connections ........................1-5 Test script parameters ......................1-7 Test procedure overview ......................1-8 Step 1: Select the TSP command set ..................1-8 Step 2: Place the output in the high-impedance output-off state ..........
  • Page 6 Table of Contents Model 2450-EC and 2460-EC User's Manual Current Pulse and Square Wave ..................1-46 Device connections ......................... 1-46 Test procedure overview ......................1-46 Test script parameters ......................1-47 Step 1: Select the TSP command set ..................1-48 Step 2: Place the output in the high-impedance output-off state ..........1-48 Step 3: Prepare the analyte and assemble the electrochemical cell ........

  • Page 7: Model 2450-Ec And 2460-Ec User's Manual

    Section 1 Model 2450-EC and 2460-EC User's Manual In this section: Introduction ................1-1 Cyclic voltammetry ..............1-3 Open circuit potential ............. 1-23 Potential Pulse and Square Wave .......... 1-32 Current Pulse and Square Wave ..........1-46 Chronoamperometry .............. 1-60 Chronopotentiometry ..............
  • Page 8 Model 2450-EC and 2460-EC User's Manual The contents of the Model 2450-EC and Model 2460-EC Electrochemistry Lab Systems consist of the following: ® One Model 2450 or Model 2460 SourceMeter SMU Instrument with six electrochemistry test scripts in internal memory. One Electrochemistry Translation Cable Accessory Kit which includes one cable and four insulated miniature alligator clips.

  • Page 9: Cyclic Voltammetry

    Model 2450-EC and 2460-EC User's Manual For protection against electrical shock while using the Keithley Instruments Model 2450, Model 2460 or other source measure units (SMU), be sure to read all the safety information and obey all warning and caution statements. The safety interlock circuit should not be activated if working with less than 42 V, but the circuit must be activated to enable the high voltage output.

  • Page 10: Simplified Cyclic Voltammetry Basics

    Model 2450-EC and 2460-EC User's Manual Simplified cyclic voltammetry basics A typical electrochemical measurement circuit consisting of an electrochemical cell, an adjustable voltage source (V ), an ammeter (A ), and a voltmeter (V ), is shown in the following figure. Figure 1: Simplified measurement circuit for performing cyclic voltammetry The three electrodes of the electrochemical cell are the working electrode (WE), reference electrode (RE), and the counter, or auxiliary, electrode (CE).

  • Page 11: Device Connections

    Model 2450-EC and 2460-EC User's Manual The voltage peaks in the waveform are the anodic (Epa) and the cathodic (Epc) peak potentials. Figure 2: Example voltammogram generated by a 2450-EC In this example, the scan begins at E1 and the potential becomes more positive, causing the anodic current (Ipa) to rise rapidly and peak at the anodic peak potential (Epa).
  • Page 12 Model 2450-EC and 2460-EC User's Manual Before beginning the experiment, the 2450 or 2460 must be properly connected to the three-electrode electrochemical cell. To perform cyclic voltammetry using a SMU, the instrument is set to force voltage and measure current in a four-wire (remote sense) configuration. Using the electrochemistry translation cable, connect the four terminals of the SMU to the three-terminal electrochemical cell as shown in the following figure.

  • Page 13: Test Script Parameters

    Model 2450-EC and 2460-EC User's Manual The figure below shows the front-panel connections on the 2450; the connections are the same for the 2460. Figure 4: Model 2450 or 2460 front-panel connections Test script parameters The cyclic voltammetry test sets certain parameters for the cyclic voltammetry test for you, and then prompts you to enter additional parameters.

  • Page 14: Test Procedure Overview

    Model 2450-EC and 2460-EC User's Manual Test procedure overview The following list outlines the basic steps to perform a cyclic voltammetry sweep and save the data to a USB flash drive using the 2450 or 2460. Details of each step are described more thoroughly in the following sections.

  • Page 15: Step 3: Prepare The Analyte And Assemble The Electrochemical Cell

    Model 2450-EC and 2460-EC User's Manual Step 3: Prepare the analyte and assemble the electrochemical cell Step 4: Connect the four output terminals of the SourceMeter instrument to the three electrodes of the electrochemical cell using the supplied cable assembly Specific information on making connections from the SourceMeter to the device is described in Device connections (on page 1-5) and also in the Model 2450-EC / 2460-EC Electrochemistry Lab...
  • Page 16 Model 2450-EC and 2460-EC User's Manual The instrument measures the open circuit potential (Eoc) of the electrochemical cell in voltmeter mode, which has high input impedance. After the Eoc is measured, the value is displayed in a user prompt, as shown in the following figure. Select OK if this value is acceptable; select Cancel to quit the program.

  • Page 17: Step 7: Define The Potential Sweep Parameters

    Model 2450-EC and 2460-EC User's Manual Step 7: Define the potential sweep parameters After the open circuit voltage is measured, the parameters of the potential sweep must be defined: Number of vertices, voltage magnitude, and reference voltage. You can select up to four voltage vertices, which are defined as E1 (or E initial), E2, E3, and E4 in the voltage versus time plot in the following figure.
  • Page 18 Model 2450-EC and 2460-EC User's Manual Voltage magnitude After the voltage vertices are defined, you must specify the magnitude of each vertex in the range of ± Figure 11: Enter potential of vertex Reference voltage After each magnitude is defined, you must select the reference type: Applied potential versus the reference potential (vs.

  • Page 19: Step 8: Select The Scan Rate

    Model 2450-EC and 2460-EC User's Manual Step 8: Select the scan rate After sweep parameters have been defined, you are prompted to enter the scan rate in units of millivolts per second (see the following figure). The scan rate, which is defined as the change of the potential as a function of time (∆V/∆t), specifies the rate at which the potential is linearly swept during the experiment.

  • Page 20: Step 9: Select The Number Of Scan Cycles

    Model 2450-EC and 2460-EC User's Manual For the 2450-EC and 2460-EC, the voltage step size depends on the scan rate and can vary from 100 µV to 10 mV. To measure the resulting current at each step, many digital potentiostats make a measurement at a fixed point during the voltage step which may not be necessarily at the same time for each step.

  • Page 21: Step 10: Select The Current Measurement Range

    Model 2450-EC and 2460-EC User's Manual The following figure shows an example of a potential versus time graph showing three cycles of a three-vertex voltage scan. Figure 18: Example potential versus time graph Step 10: Select the current measurement range After selecting the number of scan cycles, you are prompted to select the maximum current range to measure the current from the scan.

  • Page 22: Step 11: Select The Sampling Interval Units

    Model 2450-EC and 2460-EC User's Manual Step 11: Select the sampling interval units During the scan, many small voltage steps are output, depending on the scan rate. To limit the number of points returned to the active buffer (current, voltage, and time readings), choose how often to make measurements by selecting one of the sampling interval units shown in the user prompt in the following figure.

  • Page 23: Step 12: Save The Data To The Usb Flash Drive On The Front Panel

    Model 2450-EC and 2460-EC User's Manual If you input test parameters that would cause the measurements to be taken at a faster rate than the instrument is sourcing, you will get the error message shown below, prompting you to enter a new scan rate and sampling interval unit.

  • Page 24: Step 13: Start The Experiment

    Model 2450-EC and 2460-EC User's Manual Step 13: Start the experiment After the prompts to save your measurements, you are prompted to begin the experiment. If you want to begin, select Yes; the scan will start immediately. If you want to end the program, select No. Figure 25: Ready to begin experiment? At any time during the scan, you can press the OUTPUT ON/OFF switch on the 2450 or 2460 front panel to stop the test.

  • Page 25: Step 15: Finish The Experiment And Select The Next Action

    Model 2450-EC and 2460-EC User's Manual Step 15: Finish the experiment and select the next action Once the experiment is completed, you will be prompted to select what the next action is: Exit, Repeat, or New. If you select Exit, the test ends. If you select Repeat, the test is repeated using the input parameters that you previously selected.
  • Page 26 Model 2450-EC and 2460-EC User's Manual Summary of user inputs The following table summarizes the user prompts for the test script. Prompt message User inputs and range of values Notes Ready to measure Eoc? Yes or No When you select Yes, the instrument sources 0 A and measures the voltage drop (Eoc) across the cell.

  • Page 27: Step 16: View The Results Saved To The Usb Flash Drive

    Model 2450-EC and 2460-EC User's Manual Prompt message User inputs and range of values Notes Enter number Enter the magnitude of the sampling Based on the sampling interval of__(units)__: interval that you will be using and units selected, you are prompted select OK for the magnitude of the interval.
  • Page 28 Model 2450-EC and 2460-EC User's Manual Figure 28: Example data as it appears in a .csv file www.oitek.com.cn 1-22 077110401 / December 2015...

  • Page 29: Open Circuit Potential

    Model 2450-EC and 2460-EC User's Manual Open circuit potential The open circuit potential (OPC) of an electrochemical cell is a voltage measurement made between the reference and working electrodes. When the open circuit potential is measured, a voltmeter with high impedance is used to measure the voltage with no current or voltage applied to the cell. Because of their high input impedance, the 2450 and 2460 can be used to make OPC measurements when configured in a 4-wire configuration as shown in the figure below.

  • Page 30: Test Procedure Overview

    Model 2450-EC and 2460-EC User's Manual Test procedure overview The following list outlines the basic steps to perform potential measurements and save the data to a USB flash drive using the Model 2450 or 2460. Details of each step are described more thoroughly in the following sections.

  • Page 31: Step 2: Place The Output In The High-Impedance Output-Off State

    Model 2450-EC and 2460-EC User's Manual Step 2: Place the output in the high-impedance output-off state Before making physical connections from the instrument to the cell, set the output of the instrument to the high-impedance output-off state. When the high impedance output-off state is selected, the output relay opens, disconnecting the instrument from the load.

  • Page 32: Step 6: Select A Settings Group To Adjust From The Main Menu

    Model 2450-EC and 2460-EC User's Manual Step 6: Select a settings group to adjust from the Main Menu After the test begins, the parameters of the open circuit must be defined from the Main Menu. These parameters are the potential range, the number of samples, and the measure interval time. Once these are defined, select Continue>>...

  • Page 33: Step 7: Save The Data To The Usb Flash Drive On The Front Panel

    Model 2450-EC and 2460-EC User's Manual Measurement interval After selecting the number of measurements to acquire, choose the measurement interval time in seconds/point. The measurement interval time is described graphically in the following figure. Figure 35: Measurement interval time You must specify a measurement interval time between 0.75 and 100 s/pt. Figure 36: Measurement interval After the test parameters are defined, you can select Continue>>...

  • Page 34: Step 8: Start The Experiment

    Model 2450-EC and 2460-EC User's Manual If you choose to save the data, a .csv file will be created with a name containing the date and time of creation. If there are more than 10,000 measurements stored, the process of saving the data may take several minutes.

  • Page 35: Step 9: View The Graph

    Model 2450-EC and 2460-EC User's Manual Step 9: View the graph To view the data graphically in real time, press the MENU key and then Graph. An x-y plot of the measured potential as a function of time will be displayed as shown below. Figure 41: Voltage versus time graph Step 10: View the data After the experiment is finished, you will be prompted whether to View Statistics for the test data,...
  • Page 36 Model 2450-EC and 2460-EC User's Manual View Statistics If you select View Statistics, you will see information about data as shown in the figure below. This includes the total number of points in the test (NumPts), the minimum measured potential (MinV), the median measured potential (MedV), the maximum measured potential (MaxV), the average measured potential (AvgV), and the standard deviation of the measured potential (StdevV), and the duration of the test (Test t).

  • Page 37: Step 11: View The Results Saved To The Usb Drive

    Model 2450-EC and 2460-EC User's Manual Step 11: View the results saved to the USB drive If you choose to save the data to the USB flash drive, the readings will be saved in a .csv file after the test is finished. To view the readings, open the file in a spreadsheet program on a computer.

  • Page 38: Potential Pulse And Square Wave

    Model 2450-EC and 2460-EC User's Manual Potential Pulse and Square Wave In the Potential Pulse and Square Wave application, the 2450 or 2460 supplies a series of up 100,000 potential pulses. At the end of each pulse, the instrument will measure the resulting current. The user can select both the peak and base levels of the pulses as well as the period, pulse width, and sample time.

  • Page 39: Test Script Parameters

    Model 2450-EC and 2460-EC User's Manual Test script parameters The Potential Pulse and Square Wave test script (PotentialPulseAndSquareWave.tsp) prompts the user to adjust certain test parameters as listed below: Pulse Levels Peak Potential: Vpeak ≤ ± 20 V Base Potential: Vbase ≤...

  • Page 40: Step 1: Select The Tsp Command Set

    Model 2450-EC and 2460-EC User's Manual Step 1: Select the TSP command set To configure the Model 2450 or 2460 to use the TSP command set: 1. Press the MENU key. 2. Under System, select Settings. 3. Select the button next to Command Set and select TSP. 4.

  • Page 41: Step 6: Select And Adjust Each Settings Group In The Main Menu

    Model 2450-EC and 2460-EC User's Manual 2. Select Potential Pulse and Square Wave. The script begins to execute immediately and the following screen will be displayed for one second. Figure 47: Start of Potential Pulse and Square Wave test script Step 6: Select and adjust each settings group in the Main Menu After the program begins, the parameters of the Potential Pulse and Square Wave must be defined from the Main Menu.
  • Page 42 Model 2450-EC and 2460-EC User's Manual Various parameters of the pulse wave are displayed in the figure below. Though not pictured, there is also a short "grace period" between the end of the measurement and the end of the pulse to allow the instrument’s analog-to-digital converter to finish.
  • Page 43 Model 2450-EC and 2460-EC User's Manual If you select the setting Base, then you will have the option to change the base potential. Figure 52: Base Potential Current Range From the Main Menu, select Current Range to set the current range for the experiment. This range constrains the currents that the instrument is capable of sourcing through the device under test, so you should choose a range above what you expect the maximum current to be.
  • Page 44 Model 2450-EC and 2460-EC User's Manual If you select the setting Period, then you will have the option to change the period of the pulse wave. Figure 55: Pulse Period If you select the setting Width, then you will be able to change the pulse width of the wave. Figure 56: Pulse Width If you select the setting Samp t (short for sample time, this is the length of time over which the actual measurement will be taken), then you can change the sample time of the measurement.
  • Page 45 Model 2450-EC and 2460-EC User's Manual End Condition Settings From the Main Menu, you can select End Conditions to bring up a menu that allows you to choose the conditions that will stop the pulse wave. Num of Cycles and Program Time are adjustable end conditions, so that you can choose how many cycles or how much time until the pulse wave terminates.
  • Page 46 Model 2450-EC and 2460-EC User's Manual If you select the setting Program Time, then you can change the amount of time during which pulses will be generated. After the specified program time, the pulse wave will stop at the nearest half-cycle. Selecting this option will automatically enable the Program Time end condition and disable the Number of Cycles end condition.
  • Page 47 Model 2450-EC and 2460-EC User's Manual If you attempt to save the setup to a file that already exists on the USB drive—one that is not "empty"—the program will ask if you want to overwrite the existing file. Figure 63: Overwrite You will be notified if the save was successful.

  • Page 48: Step 7: Save The Data To The Usb Drive On The Front Panel

    Model 2450-EC and 2460-EC User's Manual Measure open circuit potential From the Main Menu, you can select Measure Eoc to measure the open-circuit potential of the device under test. The open-circuit potential is the potential across the terminals under a no-load condition.

  • Page 49: Step 8: Start The Experiment

    Model 2450-EC and 2460-EC User's Manual If you choose Yes, a .csv file will be created with a name containing the date and time of its creation, and results will be saved to it at the end of the experiment. Note that if there are more than 10,000 measurements made, the process of saving may take several minutes.

  • Page 50: Step 10: View The Data

    Model 2450-EC and 2460-EC User's Manual Step 10: View the data After the experiment is finished, you will be prompted whether to View Statistics for the test data, Repeat the experiment using the same settings, Change Settings in the Main Menu, or Exit the program.

  • Page 51: Step 11: View The Results Saved To The Usb Drive

    Model 2450-EC and 2460-EC User's Manual Repeat If you select Repeat, the test will begin again using the same settings as originally set. You will be prompted to save the data. Change Settings If you select Change Settings, you will return to the Main Menu to start the test again. Exit You will be asked if you want to exit the program.

  • Page 52: Current Pulse And Square Wave

    Model 2450-EC and 2460-EC User's Manual Current Pulse and Square Wave In the Current Pulse and Square Wave application the 2450 or 2460 supplies a series of up 100,000 current pulses. At the end of each pulse the 2450 or 2460 will measure the resulting potential. The user can select both the peak and base levels of the pulses as well as the period, pulse width, and sample time.

  • Page 53: Test Script Parameters

    Model 2450-EC and 2460-EC User's Manual Test script parameters The Current Pulse and Square Wave test script (CurrentPulseAndSquareWave.tsp) prompts the user to adjust certain test parameters as listed below: Pulse Levels Peak Current: 2450: Ipeak ≤ ± 1.05 A 2460: Ipeak ≤ ± 7.35 A Base Current: 2450: Ipeak ≤...

  • Page 54: Step 1: Select The Tsp Command Set

    Model 2450-EC and 2460-EC User's Manual Step 1: Select the TSP command set To configure the MStep odel 2450 or 2460 to use the TSP command set: 1. Press the MENU key. 2. Under System, select Settings. 3. Select the button next to Command Set and select TSP. 4.

  • Page 55: Step 6: Select And Adjust Each Settings Group In The Main Menu

    Model 2450-EC and 2460-EC User's Manual 2. Select Current Pulse and Square Wave. The script begins to execute immediately and the following screen will be displayed for one second. Figure 76: Start of Current Pulse and Square Wave test script Step 6: Select and adjust each settings group in the Main Menu After the program begins, the parameters of the Current Pulse and Square Wave must be defined from the Main Menu.
  • Page 56 Model 2450-EC and 2460-EC User's Manual Various parameters of the pulse wave are displayed in the figure below. Though not pictured, there is also a short "grace period" between the end of the measurement and the end of the pulse to allow the instrument’s analog-to-digital converter to finish.
  • Page 57 Model 2450-EC and 2460-EC User's Manual If you select the setting Base, then you will have the option to change the base current. Figure 81: Base Current Potential Range From the Main Menu, select Potential Range to set the potential range for the experiment. This range constrains the potential that the instrument is capable of sourcing through the device under test, so you should choose a range above what you expect the maximum potential to be.
  • Page 58 Model 2450-EC and 2460-EC User's Manual If you select the setting Period, then you will have the option to change the period of the pulse wave. Figure 84: Pulse Period If you select the setting Width, then you will be able to change the pulse width of the wave. Figure 85: Pulse Width If you select the setting Samp t (short for sample time, this is the length of time over which the actual measurement will be taken), then you can change the sample time of the measurement (see the...
  • Page 59 Model 2450-EC and 2460-EC User's Manual End Condition Settings From the Main Menu, you can select End Conditions to bring up a menu that allows you to choose the conditions that will stop the pulse wave. Num of Cycles and Program Time are adjustable end conditions, so that you can choose how many cycles or how much time until the pulse wave terminates.
  • Page 60 Model 2450-EC and 2460-EC User's Manual If you select the setting Program Time, then you can change the amount of time during which pulses will be generated. After the specified program time, the pulse wave will stop at the nearest half-cycle. Selecting this option will automatically enable the Program Time end condition and disable the Number of Cycles end condition.
  • Page 61 Model 2450-EC and 2460-EC User's Manual If you attempt to save the setup to a file that already exists on the USB drive—one that is not "empty"—the program will ask if you want to overwrite the existing file. Figure 92: Overwrite? You will be notified if the saving was successful.

  • Page 62: Step 7: Save The Data To The Usb Drive On The Front Panel

    Model 2450-EC and 2460-EC User's Manual Measure open circuit potential From the Main Menu, you can select Measure Eoc to measure the open-circuit potential of the device under test. The open-circuit potential is the potential across the terminals under a no-load condition.

  • Page 63: Step 8: Start The Experiment

    Model 2450-EC and 2460-EC User's Manual If you choose Yes, a .csv file will be created with a name containing the date and time of its creation, and results will be saved to it at the end of the experiment. Note that if there are more than 10,000 measurements made, the process of saving may take several minutes.

  • Page 64: Step 10: View The Data

    Model 2450-EC and 2460-EC User's Manual Step 10: View the data After the experiment is finished, you will be prompted whether to View Statistics for the test data, Repeat the experiment using the same settings, Change Settings in the Main Menu, or Exit the program.

  • Page 65: Step 11: View The Results Saved To The Usb Drive

    Model 2450-EC and 2460-EC User's Manual Repeat If you select Repeat, the test will begin again using the same settings as originally set. You will be prompted to save the data. Change Settings If you select Change Settings, you will return to the Main Menu to start the test again. Exit You will be asked if you want to exit the program.

  • Page 66: Chronoamperometry

    Model 2450-EC and 2460-EC User's Manual Chronoamperometry In Chronoamperometry the Model 2450 or 2460 steps the potential to a user-selected value where it is held constant for a specified period of time. While this potential is held, the instrument will measure the resulting current at a user-defined time intervals.

  • Page 67: Test Script Parameters

    Model 2450-EC and 2460-EC User's Manual Test script parameters The chronoamperometry test script (Chronoamperometry.tsp) prompts the user to adjust certain test parameters as listed below: Step Potential: Vstep ≤ ± 20 V Step Duration: 0.01 s ≤ Time ≤ 99,999 s Current Range: 2450: 10 nA, 100 nA, 1 µA, 10 µA, 100 µA, 1 mA, 10 mA, 100 mA, 1 A 2460: 1 µA, 10 µA, 100 µA, 1 mA, 10 mA, 100 mA, 1 A, 4 A, 5 A, 7 A...

  • Page 68: Step 5: Execute The Chronoamperometry Test Script

    Model 2450-EC and 2460-EC User's Manual Step 5: Execute the Chronoamperometry test script 1. At the top of the home screen, touch the active script indicator. A list of available scripts is displayed. Figure 104: Selecting the Chronoamperometry test script 2.

  • Page 69: Step 6: Select And Adjust Each Settings Group In The Main Menu

    Model 2450-EC and 2460-EC User's Manual Step 6: Select and adjust each settings group in the Main Menu After the program begins, the parameters must be defined from the Main Menu. The option Step Settings allows you to change the potential value and duration of the potential step, and to add up to 8 total steps in sequence.
  • Page 70 Model 2450-EC and 2460-EC User's Manual Step Settings In chronoamperometry, the potential will be stepped to a specific value and remain there for a specific duration of time. From the Main Menu, you can select Step Settings to bring up a menu that allows you to set the number of potential steps to be sequentially executed, and the potential and duration for each measurement.
  • Page 71 Model 2450-EC and 2460-EC User's Manual From this menu, you can set the specific step Potential or Time, or you can select -Remove Step- to delete the step. Figure 110: Set Specific Step Potential Figure 111: Set Specific Step Duration Keithley Instruments’...
  • Page 72 Model 2450-EC and 2460-EC User's Manual Click Add Step to add another step. You can set as many as eight total steps. Figure 113: Multi-Step Chronoamperometry Current Range From the Main Menu, select Current Range to set the current range for the experiment. This range constrains the currents that the instrument is capable of sourcing through the device under test, so you should choose a range above what you expect the maximum current to be.
  • Page 73 Model 2450-EC and 2460-EC User's Manual Select Interval to set the measurement interval. Figure 116: Measurement interval From the Measurement menu, you can also change the Sample Time. The instrument will average the measurement over this duration. Longer sample times will reduce the effect of noise on the measurement.
  • Page 74 Model 2450-EC and 2460-EC User's Manual If you attempt to save the setup to a file that already exists on the USB drive—one that is not "empty"—the program will ask if you want to overwrite the existing file. Figure 119: Overwrite dialog You will be notified if the saving was successful.

  • Page 75: Step 7: Save The Data To The Usb Drive On The Front Panel

    Model 2450-EC and 2460-EC User's Manual Measure open circuit potential From the Main Menu, you can select Measure Eoc to measure the open-circuit potential of the device under test. The open-circuit potential is the potential across the terminals under a no-load condition.

  • Page 76: Step 8: Start The Experiment

    Model 2450-EC and 2460-EC User's Manual If you choose Yes, a .csv file will be created with a name containing the date and time of its creation, and results will be saved to it at the end of the experiment. Note that if there are more than 10,000 measurements made, the process of saving may take several minutes.

  • Page 77: Step 9: View The Graph

    Model 2450-EC and 2460-EC User's Manual Step 9: View the graph As the test begins an x-y plot of the measured current as a function of time will be displayed as shown below. When the test completes, you can revisit the graph by pressing the MENU key, then Graph.
  • Page 78 Model 2450-EC and 2460-EC User's Manual View Statistics If you select View Statistics, you will see information about data as shown in the figure below. This includes the total number of points in the test (NumPts), the minimum measured current (MinI), the median measured current (MedI), the maximum measured current (MaxI), the average measured current (AvgI), and the standard deviation of the measured current (StdevI), and the duration of the test (Test t).

  • Page 79: Step 11: View The Results Saved To The Usb Drive

    Model 2450-EC and 2460-EC User's Manual Repeat If you select Repeat, the test will begin again using the same settings as originally set. You will be prompted to save the data. Change Settings If you select Change Settings, you will return to the Main Menu to start the test again. Exit You will be asked if you want to exit the program.

  • Page 80: Chronopotentiometry

    Model 2450-EC and 2460-EC User's Manual Chronopotentiometry In Chronopotentiometry, the 2450 or 2460 steps the supplied current to a user-selected value where it is held constant for a user-specified period of time. While this current is held constant, the instrument will measure the resulting potential at user defined time intervals.

  • Page 81: Test Script Parameters

    Model 2450-EC and 2460-EC User's Manual Test script parameters The Chronopotentiometry test script (Chronopotentiometry.tsp) prompts the user to adjust certain test parameters as listed below: Step current: Vstep ≤ ± 20 V 2450: Istep ≤ ± 1.05 A 2460: Istep ≤ ± 7.35 A Step Duration: 0.01 s ≤...

  • Page 82: Step 5: Execute The Chronopotentiometry Test Script

    Model 2450-EC and 2460-EC User's Manual Step 5: Execute the Chronopotentiometry test script 1. At the top of the home screen, touch the active script indicator. A list of available scripts is displayed Figure 133: Selecting the Chronopotentiometry test script 2.

  • Page 83: Step 6: Select And Adjust Each Settings Group In The Main Menu

    Model 2450-EC and 2460-EC User's Manual Step 6: Select and adjust each settings group in the Main Menu After the program begins, the parameters must be defined from the Main Menu. The option Step Settings allows you to change the current value and duration of the current step, and to add up to 8 total steps in sequence.
  • Page 84 Model 2450-EC and 2460-EC User's Manual Step Settings In Chronopotentiometry, the current will be stepped to a specific value and remain there for a specific duration of time. From the Main Menu, you can select Step Settings to bring up a menu that allows you to set the number of current steps to be sequentially executed as well as the current and duration of each step.
  • Page 85 Model 2450-EC and 2460-EC User's Manual From this menu, you can set the specific step Current or Time, or you can select -Remove Step- to delete the step. Figure 139: Set Specific Step Current Figure 140: Set Specific Step Duration The Keithley Instruments Chronopotentiometry and Chronoamperometry programs give you the flexibility to add up to eight steps, though such multi-step procedures are not common.
  • Page 86 Model 2450-EC and 2460-EC User's Manual Click Add Step to add another step. You can set as many as eight total steps. Figure 142: Adding Another Step Potential Range From the Main Menu, select Potential Range to set the potential range for the experiment. This range constrains the potential that the instrument is capable of sourcing through the device under test.
  • Page 87 Model 2450-EC and 2460-EC User's Manual Select Interval to set the measurement interval. Figure 145: Measurement Interval From the Measurement menu, you can also change the Sample Time. The instrument will average the measurement over this duration. Longer sample times will reduce the effect of noise on the measurement.
  • Page 88 Model 2450-EC and 2460-EC User's Manual If you attempt to save the setup to a file that already exists on the USB drive—one that is not empty— the program will ask if you want to overwrite the existing file. Figure 148: File already exists, Overwrite? You will be notified if the saving was successful.

  • Page 89: Step 7: Save The Data To The Usb Drive On The Front Panel

    Model 2450-EC and 2460-EC User's Manual Measure open circuit potential From the Main Menu, you can select Measure Eoc to measure the open-circuit potential of the device under test. The open-circuit potential is the potential across the terminals under a no-load condition.

  • Page 90: Step 8: Start The Experiment

    Model 2450-EC and 2460-EC User's Manual If you choose Yes, a .csv file will be created with a name containing the date and time of its creation, and results will be saved to it at the end of the experiment. Note that if there are more than 10,000 measurements made, the process of saving may take several minutes.

  • Page 91: Step 9: View The Graph

    Model 2450-EC and 2460-EC User's Manual Step 9: View the graph As the test begins an x-y plot of the measured current as a function of time will be displayed as shown below. After exiting the script, the graph can be viewed by pressing the MENU key, then Graph.
  • Page 92 Model 2450-EC and 2460-EC User's Manual View Statistics If you select View Statistics, you will see information about data as shown in the figure below. This includes the total number of points in the test (NumPts), the minimum measured potential (MinV), the median measured potential (MedV), the maximum measured potential (MaxV), the average measured potential (AvgV), and the standard deviation of the measured potential (StdevV), and the duration of the test (Test t).

  • Page 93: Step 11: View The Results Saved To The Usb Drive

    Model 2450-EC and 2460-EC User's Manual Repeat If you select Repeat, the test will begin again using the same settings as originally set. You will be prompted to save the data. Change Settings If you select Change Settings, you will return to the Main Menu to start the test again. Exit You will be asked if you want to exit the program.

  • Page 94: Remote Operation

    Model 2450-EC and 2460-EC User's Manual Remote operation ® The code for the test scripts was created using Keithley Test Script Processor (TSP ) code. TSP ® technology embeds complete test programs inside the instrument. The SourceMeter instruments have an internal processor that makes them capable of executing test programs (scripts) without the use of an external computer.

  • Page 95: Editing The Test Script

    Keithley Instruments support website (http://www.tektronix.com/keithley). This editing tool has built-in debugging capability and enables code execution before you download the script to the instrument. More information about Test Script Processor and Test Script Builder can be found in the "Introduction to TSP operation" and "TSP command reference"...

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