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Sweep Techniques
Linear Sweep Voltammetry with linear and log output
Cyclic Voltammetry

Step Techniques
Chronoamperometry
Chronocoulometry

Pulse Techniques
Differential Pulse Voltammetry and Polarography
Normal Pulse Voltammetry and Polarography
Sampled Current Polarography

Square Wave Techniques
Barker Square Wave Voltammetry and Polarography
Osteryoung Square Wave Voltammetry

A.C. Voltammetric Techniques
Sinusoidal A.C. Voltammetry and Polarography
Phase-Selective Sinusoidal A.C. Voltammetry and Polarography
Second-Harmonic Sinusoidal A.C. Voltammetry and Polarography
Triangular Wave A.C. Voltammetry and Polarography
Differential Triangular Wave A.C. Voltammetry and Polarography

Hydrodynamic Techniques
Rotating Disk Voltammetry
Hydrodynamic Modulation

Stripping Techniques
Barker Square Wave Stripping Voltammetry
Differential Pulse Stripping Voltammetry
Linear Sweep Stripping Voltammetry
Osteryoung Square Wave Stripping Voltammetry

Time Base
Amperometric
Differential Pulse
Triple Pulse

Miscellaneous
Bulk Electrolysis with Coulometry
Electrocapillary Curve
Impedance
Programmable Potential Wave Form

Table 1-1.  Electrochemical repertoire of the BAS 100B/W.

Содержание 100B/W

Страница 1: ...AS 100B W Version 2 3 March 2001 MF 9094 INSTRUCTION MANUAL B i o a n a l y t i c a l S y s t e m s I n c 2701 Kent Avenue W e s t L a f a y e t t e I n d i a n a 4 7 9 0 6 Electrochemical Workstation...

Страница 2: ...emark of Bioanalytical Systems Inc MS DOS and Windows are registered trademarks of Microsoft Corporation Other trademarks referenced are the properties of their respective owners 1999 2001 Bioanalytic...

Страница 3: ...ES 3 3 3 9 SETUP 3 3 3 10 TEXT DATA FORMAT 3 5 3 11 EXIT 3 5 4 METHOD MENU 4 1 4 1 LOAD SAVE METHOD 4 1 4 2 SELECT MODE 4 1 4 3 GENERAL SPECIFIC PARAMETERS 4 2 4 4 LIST PARAMETERS 4 2 4 5 FILTER 4 3 4...

Страница 4: ...SWEEP TECHNIQUES LSV CV LOGI CYCLE 10 4 10 2 POTENTIAL STEP TECHNIQUES CA CC STEP 10 13 10 3 PULSE TECHNIQUES SCP NPV P DPV P 10 21 10 4 SQUARE WAVE TECHNIQUES OSWV BSWV P 10 28 10 5 A C TECHNIQUES AC...

Страница 5: ...ows instrument control and data storage and processing together with data presentation on the PC monitor laser printer or digital plotter These functions are shown in a block diagram in Figure 1 1 I O...

Страница 6: ...A C Voltammetry and Polarography Second Harmonic Sinusoidal A C Voltammetry and Polarography Triangular Wave A C Voltammetry and Polarography Differential Triangular Wave A C Voltammetry and Polarogra...

Страница 7: ...routines Anson Cottrell and Tafel plots Laser printer and digital plotter output Multiple data set display and printing Digital smoothing by Moving Average Least Squares and Fourier Transform Integra...

Страница 8: ...Ranges 100 milliamperes volt 10 milliamperes volt 1 milliamperes volt 100 microamperes volt 10 microamperes volt 1 microampere volt 100 nanoamperes volt Fullscale output 10 volts Input voltage drift 5...

Страница 9: ...pment the carrier is responsible for its safe delivery The following are some guidelines to follow when damage is discovered You should contact the carrier directly for specific claim procedures Unite...

Страница 10: ...ility in connection with the sale installation service or use of its instrumentation BAS shall have no liability whatsoever for special consequential or punitive damages of any kind from any cause ari...

Страница 11: ...Information Bioanalytical Systems provides a skilled staff available to solve you technical and equipment oriented problems For service call 765 463 4527 during normal working hours Eastern Standard...

Страница 12: ...The A C frequency may be either 50 or 60 Hz The main power source in the location must be the same as the voltage selected in the power cord connector on the rear panel of the Analyzer see Figure 2 1...

Страница 13: ...2 2 Figure 2 1 Rear panel of BAS 100B the ports that are not required for the BAS 100B W are omitted FUSE PULL FUSE VOLTAGE SELECT PCB Figure 2 2 Power connector and voltage select...

Страница 14: ...tened to an external earth ground for safety and proper operation A proper ground connection cannot be overemphasized The power cord is shipped as a separate item and must be plugged into the connecto...

Страница 15: ...ower socket push up the plastic window and plug in the female end of the power cord The plug type on the male end of the power cord may vary depending on the country of destination The A C frequency i...

Страница 16: ...ting movement of the line or cell Cell Stand Connector This connector is used to control cell stand functions i e stirring gas purging and drop knocking and is plugged into the CELL STAND port on the...

Страница 17: ...panel of the Analyzer CGME The purge and stir functions on the BAS Controlled Growth Mercury Electrode CGME can be controlled manually or through the BAS 100B W In addition the knock and dispense rou...

Страница 18: ...600 Line 22 of this cable must be disconnected for proper operation of the 303A Early versions of the BAS 100A require line 22 to be cut Later versions of the BAS100A and BAS 100B have a jumper on the...

Страница 19: ...stom port are the Low Current Module the Power Module Potentiostat the Rotating Disk Electrode and the AC Impedance Module More details are included in each of the accessories operations manual Plotte...

Страница 20: ...ck and slide card retainer plates outward c Remove necessary ribbon cables Item 3 by pressing ejectors outward from connectors and remove d Remove the old CPU board bottom board by pressing ejectors I...

Страница 21: ...aces that build up static charge Figure 2 8 CPU Board c Carefully pry ROM 1 out of its socket be careful not to bend the legs of the chips d Properly align new ROM1 on the socket and press in It is im...

Страница 22: ...l interface connector for a parallel port printer e g laser printer h PS 2 mouse do NOT use a serial mouse PC Connections The important connections are a VGA video display connector b Keyboard connect...

Страница 23: ...ed with MS DOS MS Windows and BAS 100W Windows software already loaded on the hard disk drive which is labeled as the C drive If a non BAS PC is being used the BAS 100W Windows software is loaded acco...

Страница 24: ...igure 2 11 Figure 2 11 Setup dialog box The Setup communications options are as follows Com Port This specifies which PC communications port is connected to the BAS 100B A value of 0 disables the comm...

Страница 25: ...ameters have been checked the Electrochemical Analyzer can be powered up The system is now ready for use Printer Plotter Configuration Although a printer plotter can be selected using the Print Option...

Страница 26: ...the sub directory selected in the Directories List field To select a file double click on the file name or click on the file name and then click OK To select two or more data files for commands that...

Страница 27: ...T CRL SPC and TAB format TXT files from earlier BAS File Service programs can also be loaded 3 3 List Data The List Data command lists the data currently in main memory This allows review of the data...

Страница 28: ...l in the BAS100W Listing box Note Files cannot be connected from one text format to another text format 3 7 Delete Files Delete Files can delete up to 100 files of any type After the file s have been...

Страница 29: ...r This activates purging stirring between experiments Couple This couples purging and stirring during the deposition step of stripping experiments Audible This activates a beep before and after each r...

Страница 30: ...column delimiters Figure 3 3 Text Data Format dialog box The file extension for each format option is indicated in parentheses The default delimiter is Comma Space and the default extension is txt Om...

Страница 31: ...using standard Windows file dialog boxes 4 2 Select Mode There are 38 Techniques available on the BAS 100B W which are divided into 9 Categories When a given Category is highlighted the modes associat...

Страница 32: ...r hydrodynamic and stripping experiments Figure 4 2 General Parameters dialog box for CV Figure 4 3 Specific Parameters dialog box for DPV Specific Parameters have default values which have been chose...

Страница 33: ...cy for the Bessel filter must be at least 10 times larger than the frequency of the electrochemical technique being used If too much filtering is used then significant distortion of the experimental d...

Страница 34: ...field Figure 4 5 Figure 4 5 Deposit Options dialog box 4 7 Stabilizing Capacitor A stabilizing capacitor is only required when using iR compensation or for Bulk Electrolysis BE experiments In both th...

Страница 35: ...attained when the potential scan is started Modulation This option switches on the modulation of the rotation rate 4 9 Controlled Growth This specifies drop growth parameters for the CGME mode of the...

Страница 36: ...50 m capillary is typically slightly less than 1 s The CGME mode can also be used for anodic stripping voltammetry Z Kowalski and J Migdalski Electroanalysis 4 1992 915 The mercury drop is grown incre...

Страница 37: ...abel that appears above the graph is cleared to indicate that the data are not yet saved For single runs the data are not saved automatically the Save Data command in the File menu must be used 5 2 Ho...

Страница 38: ...he Main window If the Find peaks after run box is checked Results Options in the Analysis menu a Results Graph and Results List is produced after each run rather than a Single Graph Note that is may r...

Страница 39: ...mer dialog box appears to count down any excess time that remains 5 6 List Run Data When this command is checked in the menu the experimental data are listed on the screen during runs if the data rate...

Страница 40: ...ccurs A 50 mV potential step E is applied around this potential i e Test E 25 mV to Test E 25 mV and the current is sampled at 54 s and 72 s after the step is applied The current decays exponentially...

Страница 41: ...ed in increments of the calculated uncompensated resistance 5 increments up to 80 2 increments from 80 to 90 and 1 increments thereafter The stability of the circuit is tested after each increment The...

Страница 42: ...re 5 4 Ringing of the current response If the desired compensation cannot be obtained using Auto iR Compensation then a user specified compensation resistance can be applied using the Manual option If...

Страница 43: ...and Cdl these are the results of the resistance measurements R to be compensated percentage of Ru used in positive feedback Uncompensated R uncompensated R remaining after compensation these are the r...

Страница 44: ...e BAS 100B W this operation was done in the factory before shipping If not it must be done by the user Figure 5 6 Impedance Control dialog box The Calibration command button generates a special calibr...

Страница 45: ...gth of time without accumulating any data This can be useful for generating clean reproducible working electrode surfaces Figure 5 8 Clean Electrode dialog box 5 12 Self Test Hardware This command ini...

Страница 46: ...l Off is selected the working electrode is only connected during experimental runs For most experiments the cell should be off between runs since there is more chance of damaging the instrument and of...

Страница 47: ...aved for binary and text files In binary files only the initial and final X points and the X sample interval are saved and the remaining X data points are generated when the file is loaded However in...

Страница 48: ...irement for the number of points is a block is that this number is odd Any odd number between 5 and 25 can be chosen on the BAS 100W the larger the number of points the greater the smoothing Least Squ...

Страница 49: ...es selected smoothing routine on the data in main memory OK This command exits the dialog box whilst retaining any changes Cancel This command exits the dialog box without saving any changes 6 3 Deriv...

Страница 50: ...a Both of these processes are available on the BAS 100W as Convolution Mode options Figure 6 4 Additional smoothing is available for semi differentiation since this process can increase the noise leve...

Страница 51: ...dialog boxes see the File menu section The potential range of the two voltammograms MUST be the same The subtracted data can be transferred to main memory using Replace Current Data Figure 6 5 Backgr...

Страница 52: ...s can be changed by the user by dragging the borders or the caption and are defined initially by the BAS100W INI file The Auto option also selects the appropriate Peak Shape The experimental results s...

Страница 53: ...within the axes A selected area can be expanded Zoomed by dragging the mouse using the left mouse button between diagonally opposite corners of the defining rectangle This operation can be reversed by...

Страница 54: ...ce a consistent sign convention The 25 mV interval is not rigid The actual value is chosen such that an odd number of data points intervene so that the I value can be assigned to the middle potential...

Страница 55: ...y to be noise rather than a real electrochemical peak This noise discrimination routine is implemented by examining the peak width at 50 100 and 150 mV preceding the peak potential Ep Figure 7 The pea...

Страница 56: ...curve 50 mV apart in a range of 250 mV preceding Ep Figure 7 4 Figure 7 4 Tailed current response c Sigmoidal curves Two baselines are required to measure the limiting current These are defined by two...

Страница 57: ...both the forward and reverse potential steps Figure 7 6 FORWARD STEP REVERSE STEP CHARGE uC 50 0 50 80 TOTAL NUMBER OF DATA POINTS OF DATA POINTS 80 TOTAL NUMBER mSEC 15 8 1 2 Figure 7 6 Selection of...

Страница 58: ...experimental data is presented when there is more than one presentation format i e BE CA and CC The default Data Types are as follows Current vs Time for CA and Charge vs Time for BE and CC Data Sets...

Страница 59: ...wise decrease in the Sensitivity Factor Find Peaks after If this command is activated the Results Graph Load Data will be displayed automatically when a data file is loaded if it is not activated the...

Страница 60: ...ration Unit must be specified In the above example a total of 10 samples were run 3 of which were standards 1 5 and 10 The Analysis parameters and results can be saved and reloaded using the Analysis...

Страница 61: ...dialog box 7 4 Standard Addition This command is used to construct a standard addition curve for quantitative analysis First the Mode must be selected and the General and Specific Parameters entered T...

Страница 62: ...used for reprocessing of existing files e g if incorrect standard additions or peak potentials were used initially Since 3 digit run numbers are used in the data filenames it may be necessary to renam...

Страница 63: ...experiment and after a data file has been loaded the Find peaks check boxes in the Results Options dialog box need to be unchecked The data are graphed according to the Data Type specified in Graph O...

Страница 64: ...hen activated both axes are drawn Zero Axes When activated dashed lines are drawn on the graph at X 0 and Y 0 if they are within the range of the graph X Y Grid When activated an X Y grid is displayed...

Страница 65: ...th a line of the given Width and select Color to draw the points and lines colored pen Data Type This defines how the experimental data is presented when there is more than one presentation format i e...

Страница 66: ...ore Note that the accuracy of the colors depends the number of colors the display adapter can depict For Multi Graphs using the Overlap option the Curve 1 through Curve 8 colors are used for the first...

Страница 67: ...text This lists the results from the data analysis Label This is an optional description of the experiment 69 characters maximum Use colors when printing This option tells the program that the printe...

Страница 68: ...fferent Modes of Operation then the default Data Sets and Data Type are used 9 4 Print Text Print Text prints any text selected highlighted by dragging the mouse over the desired lines in the Main win...

Страница 69: ...t a fixed value or is stepped between two values and the current response is monitored as a function of time b Stationary solution vs Hydrodynamic This determines the rate at which electroactive molec...

Страница 70: ...nic Alternating Current Voltammetry Polarography SHACV P Triangular wave Alternating Current Voltammetry Polarography TACV P Differential Triangular wave Alternating Current Voltammetry Polarography D...

Страница 71: ...ential is 3276 to 3276 mV b Sensitivity This is the gain of the current to voltage converter output For all techniques except CC IMP and LOGI the range of sensitivities is 100 mA V to 10 pA V although...

Страница 72: ...ue In CV the potential can be cycled over the same range many times Three potential parameters are required the initial potential Initial E and the two switching potentials i e the potential at which...

Страница 73: ...otential wave form for CV The peak current for a reversible process is given by the Randles Sevcik equation i x n AD C p 2 69 10 5 3 2 1 2 1 2 where ip peak current A n number of electrons transferred...

Страница 74: ...to separate the effects of slow electron transfer and chemical reactivity The charging current that is present in CV and LSV limit their usefulness as techniques for quantitative analysis However LSV...

Страница 75: ...er Basic CV R E Shoup 4 1982 31 2 Cyclic Voltammetry as a Tool for Assessing Dual Electrode Detector Feasibility R E Shoup 4 1982 48 3 Electrochemistry for the Nonelectrochemist P T Kissinger 6 1985 6...

Страница 76: ...rent is controlled only by the rate of electron transfer Such plots are called Tafel plots and are used to obtain transfer coefficients and exchange currents These are frequently used in corrosion stu...

Страница 77: ...elements The resolution of the staircase potential wave form is 0 1 mV which generates a potential range of 3276 mV The rate at which the potential can change the Scan Rate is dependent on the rate at...

Страница 78: ...22 9309 1 mV s resolution Table 10 1 Some allowed Scan Rates for mV s For Scan Rates of V s the resolution of the staircse is 1 6 mV A list of some Scan Rates for this resolution are shown in Table 1...

Страница 79: ...the same as Number of Segments 2 e The maximum Number of Segments is determined by the data storage capacity and hence depends on the potential range Sample Interval etc Graphics Menu LSV and CV Sing...

Страница 80: ...are listed in the Main window Tafel slopes and intercepts can be measured using the Manual option The user must define the slope of the line by specifying two X values on the plot In addition the axi...

Страница 81: ...ped from Initial E to either Low E or High E this is determined by the Initial Direction Positive or Negative respectively After time the Pulse Width the potential can be stepped in the opposite direc...

Страница 82: ...where i current A n number of electrons transferred per molecule F Faraday s constant 96 485 C eq A electrode area cm2 D diffusion coefficient cm2 s C concentration mol cm3 t time s The diffusion cont...

Страница 83: ...have lower detection limits so CA and CC are generally not used for concentration measurements However A and D are frequently measured using these techniques 1 3 The relationship between i and t 1 2 o...

Страница 84: ...by the rate of heterogeneous electron transfer as well as the rate of diffusion The rate of electron transfer can therefore be measured by CA and CC 5 CC has several advantages over CA The signal inc...

Страница 85: ...e Anson plots References 1 BAS Capsule No 133 Determination of Electrode Area with Chronocoulometry 2 BAS Capsule No 143 Determination of Diffusion Coefficients Using Chrono coulometry 3 W R Heineman...

Страница 86: ...nu The Auto option for Results Graph displays the plot selected in Data Type and the slope intercept and correlation coefficient are listed in the Main window Since data at early time points can be di...

Страница 87: ...plot If this occurs the initial current must be decreased by for example decreasing the concentration and or the electrode surface area The automatic discharge is not allowed for the 100 nC V and 1 C...

Страница 88: ...Initial Direction Negative Negative or Positive Pulse width msec 250 1 to 32000 Number of Cycles 1 0 to 65535 Sensitivity 1 A V 100 mA V to 10 pA V Specific parameters Quiet Time sec 2 0 to 65535 Com...

Страница 89: ...Width The current is sampled and averaged 16 times per msec The default Sample Width is the time required for 1 line cycle d Pulse Period Dropping Time This is the time required for one potential cycl...

Страница 90: ...at the end of each drop The Drop Time and the size of the potential step can be varied through variation of the Scan Rate This potential waveform is often referred as a staircase waveform E SAMPLING...

Страница 91: ...the pulse amplitude is sufficiently large that the pulsed potential is around the redox potential there is a faradaic reaction in response to the pulse assuming moderately rapid electron transfer kin...

Страница 92: ...rential Pulse Voltammetry Polarography DPV P is different from the previous two techniques in that the current is sampled twice in each Pulse Period The potential wave form is shown in Figure 10 14 Th...

Страница 93: ...s intermediate between NPV P and SCP 20 A mM but the detection limit of DPV P is significantly lower 10 7 M due to more effective discrimination against the charging current Mode SCP General Parameter...

Страница 94: ...the Low Current Module Specific Parameters Scan Rate mV sec 20 4 1 to 200 Sample Width msec 17 1 to 250 Pulse Width msec 50 3 to 2000 Pulse Period msec 200 40 to 8000 Drop Time msec 1000 100 to 8000...

Страница 95: ...3 to 2000 Pulse Period msec 200 40 to 8000 Drop Time msec 1000 100 to 8000 Quiet Time sec 2 0 0 to 65535 Comments a Pulse Period is used for DPV and Drop Time is used for DPP When the default paramete...

Страница 96: ...nu The Auto option for Results Graph displays the current vs potential plot and the peak potential and peak current are listed in the Main window Alternative baselines can be set by the user through t...

Страница 97: ...ief advantages are the greater sensitivity and the faster speed for OSWV There are two different square wave potential wave forms available on the BAS 100B W Osteryoung OSWV and Barker BSWV P These ar...

Страница 98: ...ent is significant so the difference current is greater than either the forward or reverse currents This is one reason for the greater sensitivity of OSWV compared with DPV P The magnitude of the reve...

Страница 99: ...3276 Sensitivity 1 A V 100 mA V to 100 nA V 10 pA V with the Low Current Module Specific Parameters Step E mV 4 1 to 40 S W Amplitude mV 25 1 to 250 S W Frequency Hz 15 1 to 2000 Sampling Points 256 1...

Страница 100: ...ow Current Module Specific Parameters Scan Rate mV s 4 1 to 200 S W Amplitude mV 25 1 to 250 S W Frequency Hz 14 5 to 250 Drop Time msec 1500 1500 to 8000 Quiet time sec 2 0 0 to 65535 Comments a Para...

Страница 101: ...e Auto option for Results Graph displays the difference current vs potential plot and the peak potential and peak current are listed in the Main window Alternative baselines can be set by the user thr...

Страница 102: ...ncentrations The A C potential will have the greatest effect at the redox potential so the A C current response for ACV P is a peak shaped curve Figure 10 21 E QUIET TIME A C AMPLITUDE PERIOD t Figure...

Страница 103: ...electrode surface area cm2 D diffusion coefficient cm2 s C concentration mol cm3 E peak to peak amplitude of A C potential 2 A C frequency As the system changes from reversible to quasi reversible an...

Страница 104: ...Hz 50 5 to 250 Drop Time msec 1500 500 to 8000 Quiet Time sec 2 0 0 to 65535 Specific Parameters for PSACV P SHACV P Phase Shift degree 0 110 0 to 360 Comments a Drop Time is used for ACP PSACP and SH...

Страница 105: ...ar to the sinusoidal techniques in that the potential waveform consists of an A C waveform superimposed on a slowly varying D C waveform However for these techniques the A C waveform is triangular Fig...

Страница 106: ...liminate the charging current Figure 10 25 and Figure 10 26 However the non linear relationship between the charging current and the applied potential may preclude complete subtraction Therefore the d...

Страница 107: ...000 Quiet Time sec 2 0 0 to 65535 Comments a Drop Time is used for TACP and DTACP The range of values allowed for the Drop Time depends on the A C Frequency The analogous parameter for TACV and DTACV...

Страница 108: ...nu The Auto option for Results Graph displays the current vs potential plot and the peak potential and peak current are listed in the Main window Alternative baselines can be set by the user through t...

Страница 109: ...metal is co deposited with the lead during the deposition step The effect of the deposition step is to concentrate the lead in the mercury electrode that is the concentration of lead in the mercury e...

Страница 110: ...faster stirring can be used with the TMFE due to the relative mechanical instability of the HMDE The signal resolution is also better with the TMFE which can be important when there is more than one...

Страница 111: ...is the analyte on the surface of the mercury electrode during the deposition step This film is then removed in the stripping step using a cathodic scan CSV is most commonly used for the detection of...

Страница 112: ...0 Sensitivity 1 A V 100 mA V to 100 nA V 10 pA V with the Low Current Module Deposit Time sec 15 0 to 65535 Specific Parameters Scan Rate mV s 4 1 to 200 S W Amplitude mV 25 1 to 250 S W Frequency Hz...

Страница 113: ...Width c Pulse Period is the time required for 1 potential cycle and must be at least twice the Pulse Width d The product of the Pulse Period and Scan Rate must be less than the Pulse Amplitude and gre...

Страница 114: ...or the staircase potential wave form b Sampling Points is the number of current samples taken and averaged at the end of each half cycle The 3 current sampling options are i 256 samples taken and aver...

Страница 115: ...vs potential plot for the stripping step and the peak potential and peak current are listed in the Main window it should be noted that the default Peak Shape for all the stripping techniques is Symmet...

Страница 116: ...ternal vibrations although such conditions can only maintained for relatively short time periods Voltammetry techniques that use stationary solution include Cyclic Voltammetry ChronoCoulometry pulse a...

Страница 117: ...best measured from the intercept of the reciprocal Levich plot 1 il vs 1 1 2 This method is often used in studies on corrosion and batteries it has also been used to measure the rate of electron tran...

Страница 118: ...is proportional to 1 2 The A C current is handled using conventional data handling techniques that is filtering followed by rectification or phase selective detection Consider the following example A...

Страница 119: ...ds on the rate of mass transport to the working electrode so there is no contribution from charging current oxidation or reduction of the electrode or adsorbed species or electrolyte solvent HDM is th...

Страница 120: ...40 Mod Frequency Hz 2 1 to 20 Mod Amplitude rpm 36 0 to less than Rotation Rate Rotation Rate rpm 3600 0 to 10000 Sensitivity A V 1 A V 1 mA V to 100 nA V 10 pA V with the Low Current Module Specific...

Страница 121: ...started during the Quiet Time to ensure that the desired rotation rate has been attained when the potentialscan is started Modulation This option switches on off the modulation of the rotation rate G...

Страница 122: ...able on the BAS 100B W is the potential wave forms used that is the potential wave forms have been modified to improve selectivity The simplest potential waveform is obviously a fixed potential and th...

Страница 123: ...PULSE WIDTH FINAL E INIT E PULSE PERIOD t SAMPLE WIDTH I INIT SAMPLING TIME MAX 8000 x PULSE PERIOD QUIET TIME Figure 10 36 Potential wave form for DPTB Figure 10 37 Typical current response for DPTB...

Страница 124: ...ials by increments which is useful during method development for determining the optimal potentials for the analysis Although this specific example has been given TPTB should be considered as a genera...

Страница 125: ...e c A Precondition potential can be applied for the Precondition Time before the start of the experiment d When enabled the Real Time Integrator adds all the current values to give the charge accumula...

Страница 126: ...duct exceeds 8000 then the Run Time is automatically adjusted to an acceptable value Graphics Menu Single Graph displays the differential current vs time plot Analysis Menu Results Graph is disabled f...

Страница 127: ...d Increment E is the incremental change in the potential following each triple pulse cycle e The maximum data length is 2000 cycles Graphics Menu Single Graph displays the current vs potential plot fo...

Страница 128: ...xiliary electrode with a large surface area e g platinum coil or gauze in addition the solution is stirred to increase the rate of mass transport to and from the working electrode The auxiliary electr...

Страница 129: ...arge vs time plot Figure 10 40 or a current vs time plot Figure 10 41 Figure 10 40 Typical charge vs time plot for BE Figure 10 41 Typical current vs time plot for BE The total charge is measured by t...

Страница 130: ...be increased or removed using the Manual option for Stabilizing Capacitor in the Method Menu However there is generally no need to use the Manual option Mode BE General Parameters Initial E mV 0 3276...

Страница 131: ...to measure the electrocapillary curve is to measure the lifetime of a dropping mercury electrode DME at different potentials The drop lifetime tmax is proportional to the surface tension the physical...

Страница 132: ...ured during this operation this does not affect the accuracy of the experiment since no drop will fall at the very beginning of its lifetime As with any experiment that uses a DME proper maintenance o...

Страница 133: ...l to be detected the current value x 2n must be less than the previous current value Graphics Menu Single Graph displays the electrocapillary curve Analysis Menu The Auto option for Results Graph disp...

Страница 134: ...ata Set 1 3 5 7 9 11 Hold E mV 0 3276 to 3276 Hold Time 0 0 to 65535 Data Sets 2 4 6 8 10 12 Initial E mV 0 3276 to 3276 Final E mV 0 3276 to 3276 Scan Rate 100 1 to 51200 Sensitivity 1 A V 100 mA V t...

Страница 135: ...commended Even when measuring 2 decades simultaneously the time required for the lowest frequency ranges may still be too long when compared to the stability of the system The BAS 100B W uses a Fourie...

Страница 136: ...re Y 1 Z A vector diagram illustrating the relationship between Z total impedance Z the impedance in phase with the applied potential Z the impedance 90o out of phase the applied potential and the pha...

Страница 137: ...potential and the current response is linear that is I E Rf where Rf is the Faradaic impedance Rf is inversely proportional to the rate of electron transfer The simplest model of an electrochemical sy...

Страница 138: ...on and battery studies They have also been used to measure the rate of electron transfer through electroactive polymer films on electrode surfaces Setting up IMP experiments The BAS Impedance Module i...

Страница 139: ...1 to 400 0 01 1 Hz 8 1 to 400 0 01 0 1 2 1 to 400 0 001 0 1 2 1 to 400 0 001 0 01 1 1 to 400 0 0001 0 01 1 1 to 400 Quiet Time sec 2 0 to 65535 Comments a The A C Amplitude should be 8 n mV or less n...

Страница 140: ...ts fans etc tighten as necessary 11 2 Troubleshooting When intermittent or unusual problems arise often they are induced into the BAS 100B through the environment or power source Ungrounded or fluctua...

Страница 141: ...NaCl where it should remain when not in use Other reference electrodes should also be stored in the appropriate solution e g saturated KCl for the saturated calomel electrode Failure to store referen...

Страница 142: ...ture changes or long term calibration drift No cause for undue concern Call BAS Customer Service for advice repair Error in several analog ranges Power supply voltages out of tolerances Test power sup...

Страница 143: ...11 4 General Protection Fault Restart BAS 100W software BAS 100B doesn t respond to PC commands Run Self Test Hardware Linked Failed error message Reset BAS 100B or restart BAS 100W software...

Страница 144: ...rack and slide card retainer plates outward c Remove necessary ribbon cables Item 3 by pressing ejectors outward from connectors and remove d Remove circuit board by pressing ejectors Item 4 outward...

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