SU1408347A1 - Device for inspecting electrochemical instruments - Google Patents

Abstract

The invention relates to measuring instruments for monitoring electrochemical instruments: polarographs and chronopotentiometers using electrochemical cell simulators. The goal is to improve the accuracy of modeling voltammetric measurements and expand the scope of application. For a device, a device containing a two-port device, made in the form of a parallel-connected resistor and a capacitor, and two circuits consisting of a series-connected current source, a diode and a resistor, additionally introduce a divider, voltage stabilizer, an OR element, an integrator, and an additional circuit of series-connected current source, diode, resistor, current regulator, and a parallel-connected switch, resistor, and capacitor. The device allows the simulation of electrochemical processes, including inversion and voltammetry and chrono-potentiometry. 1 il. with S (L f about 00 oe 42m

Description

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 The invention relates to a measurement technique and is intended to monitor the operability of electrical devices (polographers, inversion voltammetric analyzers, inversion chronopogenometers, etc.) during their creation and operation and can be applied in the electronic industry during the development , production of electrochemical devices, in other areas of the industry when setting up, operating electrochemical devices.

The purpose of the invention is to increase the accuracy of simulation of voltammetric measurements and expand the scope of application due to the possibility of modeling inversion voltammetric and chronopotentiometric analysis processes.

The drawing shows a functional diagram of the proposed device.

The device contains input terminals corresponding to auxiliary 1 and indicator 2 electrodes, and reference electrode 3, capacitors 4 and 5, resistors 6-12, semiconductor diodes 13-17, power sources 18-20, switch 21, current regulator 22 , element OR 23, voltage regulator 24, divisor 25, integrator {26, in which the capacitor 27 determines the time constant

| rovani. Between the indicator 2 and ancillary 1 electrodes, the two-pole is connected in the form of a parallel-connected resistor 6 and a capacitor 4 and three electrical circuits: the first circuit consists of a series 18 current source 18, a diode 13, a resistor 7, and the second from source 19 current, diode 14, resistor 18, one third - from current source 20, diode 15 resistor 10, current stabilizer 22 and parallel connected switch 21, resistor 9 and capacitor 5. The input of integrator 26 is connected through, divider 25 to resistor 10, which is connected between stabilizer 22 and a diode 15, while parallel to the capacitor 27 determining the time constant of the integrator 26, a resistor 12 and two diodes 16 and 17 connected in series are connected, and the integrator output is connected to the first input of the element OR 23 through the voltage regulator 24, the second input which

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go is connected to the input terminal of the auxiliary electrode, and the output through a resistor 11 is connected to the input terminal 5

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my - Comparison electrode, and in-; The formation input of voltage regulator 24 is connected to a current source 20.

The device works as follows.

The capacitor 4 simulates the charge of the electric double layer, the resistor 6 the Faraday component of the residual current, the resistor 11 the internal resistance of the reference electrode. With closed contacts of switch 21, a cell with stationary diffusion conditions is simulated (the solution is mixed vigorously, the mode used in the inversion electrochemical analysis methods in the deposition stage).

The occurrence of a current limit is simulated by a current stabilizer 22. The concentration of the analyzed ions is determined by the current strength of the stabilizer 22. The half-wave potential is determined by the voltage of the current source 20. Resistor 7 determines the slope of the branch of the voltammogram. Thus, as the potential of the indicator electrode increases, a background current appears (determined by resistor 6 and capacitor 4), then when the potential of current source 20 reaches, the diode 15 opens, and a current appears, which is determined by current stabilizer 22.

As the cathode potential increases to the value of current source 18, diode 13 is opened, and a current arises through resistor 7 that simulates the discharge of the background electrolyte and the evolution of hydrogen at the indicator electrode. The oxygen distribution in the anode potential region models the electrical circuit from current source 19, diode 14 and resistor 8. The oxygen release potential is determined by the current source. The value of resistor 8 determines the slope of the voltamogram.

If the contacts of the switch 21 are open, a cell with non-steady diffusion conditions is simulated (the solution is not mixed, the mode used in the polarography). In this case, the concentration of the analyzed ions in the diffusion region decreases as a result of their discharge on the indicator electrode.

the discharge current of the ions being analyzed is reduced. This process is simulated by charging capacitor 5. At first, the capacitor 5 is discharged, and the current flowing through it is maximum (determined by stabilizer 22), then as the capacitor discharges, the current through it decreases to zero (the total discharge of the analyzed ions in the diffusion region). Resistor 9 determines the migration current through the cell.

The release of the analyte at the indicator electrode when the equilibrium potential is exceeded by 0.1 ± 0.2 V is modeled by a resistor 10. That is, For the current stabilizer to reach the specified mode, it is necessary to exceed not only the voltage of the current source 20 (and the direct voltage drop across the diode 15), but also the voltage drop across the resistor 10. In the cathodic electrodeposition stage, the voltage from the resistor 10 is supplied through a divider 25 an integrator 26. At the output of the latter, a linearly increasing voltage is formed. Output signal

When using a device for controlling inversion polarographs (differential-pulse or linear potential sweep), all stages except for anodic electrolytic dissolution are identical to the method of inversion chronopotentiometry. In the stage of electrodissolution, the approach of the sweep potential to Ey

integrator 26 arrives at the entrance of the stazo; a peak of anodic dissolution occurs.

voltage bilizator 24, which limits stresses to tg. Since the input voltage on the electrodes 1 and 2 is higher than the voltage from the output of the stabilizer 24, the input voltage is applied to the electrode 3 through the element OR 23. In the settling down stage, the current is usually not passed through the cell, so capacitor 4 is quickly discharged through resistor 6, and the voltage at terminal 3 is determined by the output voltage of stabilizer 24.

The dissolution of the analyte by the action of dissolved oxygen is modeled by the discharge current of the capacitor 27 through the resistor 12. The magnitude of the current on the latter determines the leakage of the capacitor 27 or, in a real cell, the degree of removal of dissolved oxygen from the electrode cell.

In the electrodissuing stage, the polarity of the input current changes. In this case, the current stabilizer is blocked, and the integrator input is connected to the input of the integrator via a blocked current stabilizer and switch 21 connected to the input terminal 1.

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Moreover, the peak height is determined by the potential sweep rate, as well as by the voltage at the integrator output. The area under the peak is determined only by the voltage at the output of the integrator

The results of testing the device showed its versatility, efficiency, and performance. Capitalization and special equipment are not required for the realization of the present invention.

Apparatus precisely simulates elements ical cell, and may be modeled Vat electrochemical cell Started melting in the following modes: inversion hydrochloric chronopotentiometry, voltammetry, stripping differential pulse voltamp rometrii, discharge ions background eg electrolyte and hydrogen evolution at the display electrode vozniknoven residual current ( Faraday component), discharge of the analyzed ions under conditions of stationary diffusion.

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Claims (1)

Invention Formula Device for controlling electrochemical devices, containing two poles, made in the form of a pair There is a voltage depending on the potential of the terminal, 1. The integrator reverses - the voltage at the integrator output decreases. In the regeneration stage of the indicator electrode, the anode current is usually abruptly increased. In this case, the capacitor 27 is further recharged to the voltage determined by opening the diodes 16 and 17. This small voltage simulates the oxidation state of the indicator electrode. The charge of the capacitor 27 to the next measurement cycle does not start from zero, but from a certain quantity characterizing the amount of electricity needed to remove the chemisorbed oxygen from the indicator electrode. When using a device for controlling inversion polarographs (differential-pulse or linear potential sweep), all stages except for anodic dissolution are identical to the method of inversion chronopotentiometry. In the stage of electrodissolution at the approach of the sweep potential to Ey there is a peak of anodic dissolution. five 0 Moreover, the peak height is determined by the potential sweep rate, as well as by the voltage at the integrator output. The area under the peak is determined only by the voltage at the integrator output. The results of testing the device showed its versatility, efficiency and efficiency. Capitalization and special equipment are not required for the realization of the present invention. The device more accurately simulates an electrochemical cell and can simulate an electrochemical cell operating in the following modes: inversion chronopotentiometry, inversion voltamperometry, inversion differential pulse voltammetry, ion discharge of the background g electrolyte and hydrogen evolution on the indicator electrode, the occurrence of residual current (Faradateedeye de ventricular wavelet). discharge of the analyzed ions under conditions of stationary diffusion. five five Invention Formula A device for monitoring electrochemical devices, containing a two-port device made in the form of a parallel-connected resistor and a connector, and two circuits, each of which consists of a series-connected current source, a diode and a resistor, which is designed to increase the accuracy of the ms | delimiting voltammetric measurements and expanding the field of application, it has additionally introduced a divider, a voltage stabilizer, an OR element, an integrator in which parallel to a capacitor, is defined as (; mu constant Meni integrator connected resistor and two diodes connected in series, and is included between the input terminals: The indicator electrode - auxiliary electrode an additional chains. consisting of a series-connected current source, a diode, a resistor, a current regulator and a parallel-connected switch, a resistor and a capacitor, the integrator entering through a divider connected to a resistor, which is included in the additional circuit between the current stabilizer and the diode, and the integrator's output through a voltage regulator is connected to the first input of the OR element, the second input of which is connected to the input terminal of the Auxiliary Electron Q 15 type and output - through a resistor with a reference Electrode, and the input of the voltage regulator is connected to an additional current source chains. / 5/7