SU1545152A1 - Differential voltamperograph - Google Patents

Abstract

The invention relates to electrochemical instrumentation and is intended for use in polarographic apparatus. The purpose of the invention is to improve the accuracy of a differential voltamperograph by subtracting the first and second voltamograms. The differential voltamperometer for working with solid electrodes contains a source of polarizing voltage, the first and second electrochemical sensors, the first and second current-voltage converters, a comparator with a set potential sampler, the first and second electronic switches, the first and second storage devices, the first and second multipliers, subtracting and recording devices. 1 il.

Description

The invention relates to electrochemical instrument making and is intended for use in polarographic apparatus.

The aim of the invention is to improve the accuracy by subtracting the first and second voltammograms.

The drawing shows a block diagram of a differential voltamperograph.

The difference voltamperograph contains a source of polarizing voltage, the first 2 and second 3 electrochemical sensors, the first 4 and second 5 current-voltage transducers, "ohm., Parator 6 with a set potential sampler, the first 7 and second 8 Keys, the first 9 and second 10 storage devices, the first 11 and second 12 multipliers, subtracting 13 and registering 14 devices, the source 1 being connected to the input of sensors 2 and 3 and the comparator 6, the output of which is connected to the control inputs of the keys 7 and 8, the signal inputs of which are connected to the first outputs of converters 4 and 5, and the outputs of sensors 2 and 3 are connected respectively to current-to-voltage converters 4 and 5, the outputs of which are connected to the first inputs of multipliers 11 and 12, and their outputs are connected to the first and second inputs of a subtractor 13, the output of which is connected to the recording device 14, and

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the inputs, the keys 7 and 8 are connected to the outputs of the converters 4 and 5, the outputs of the keys 7 and 8 are connected to the inputs of the storage devices 9 and 10, the outputs of which are respectively connected to the second inputs of multipliers 11 and 12.

The device works as follows.

The linearizing voltage polarizing from source 1 is supplied to wiring devices 2 and 3 and to the comparator 6. At B1, converters 4 and 5 appear voltages proportional to the sensor currents. When the voltage reaches the specified value, in the comparator 6, it outputs to the control inputs of the keys 7 and 8 a short pulse, during which the storage devices 9 and 10 fix respectively the voltages acting on the outputs of the transducer flies 4 and 5. The voltage fixed to storage device 10, under efs on the second the multiplier 11 moves, and the voltage recorded on the storage device 9 is fed to the second input of the multiplier 12. Moreover, the value of the specified voltage on the computer is chosen in the range at which the electrochemical reduction of the detected substance in the cell does not pass, t . no useful signal. As a result, n4 output subtractive device 13

the signal is zero.

; Upon reaching a polarizing voltage, the voltage range at which the electrochemical reaction takes place is qi; , at the output of the subtractor; 13 a signal appears proportionally

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the concentration of the substance being determined.

The device allows to automatically balance the measurement channels of differential polarographs when working with solid electrodes and to improve the measurement accuracy.

Claims (1)

Invention Formula Differential voltamperograph for working with solid electrodes containing a source of polarizing voltage, the outputs of which are connected to the anodes of the first and second electrochemical sensors, the cathodes of which are connected to the inputs of the first and second current-voltage converters, the subtractive device, the output of which is connected to the input of the recording device , characterized in that, in order to improve the accuracy by subtracting the first and second voltamograms, a comparator with a sampling potential generator is introduced into it, sequentially connected the first electronic switch, a first storage device and a second multiplier, serially connected second electronic switch, the second storage device and a first multiplier, wherein the control inputs are connected to the keys The yields. the comparator house, the signal inputs of the first and second keys and the second inputs of the first and second multipliers are connected respectively to the outputs of the first and second current-voltage converters, the outputs of the multipliers are connected to the inputs of the subtractor, the comparator input is connected to the output of the polarizing voltage source.