SU1427282A1 - Voltamperograph - Google Patents

Abstract

The invention relates to polarography and can be used for a wide class of electrophysical and electroanalytical studies. The aim of the invention is to increase the sensitivity of measurements by reducing the level of capacitive current. For this purpose, a signal driver, included in the measurement path, a nonlinear controlled inductance and a controller, are additionally introduced into the device. A nonlinear controlled inductance with a sensor forms a parallel circuit over the entire range of operating voltages of the waveform. The controller generates a correction signal that is summed algebraically with the current of the voltamperograph sensor. 1 il.

Description

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The invention relates to electrophysical and electroanalytical studies, in particular to devices for polarographic analysis, and can be used in various areas of the national economy.

The aim of the invention is to increase sensitivity by reducing the capacitive current level of a voltamperograph.

The block diagram of the voltampergraph is shown in the drawing.

The device contains a linearly varying voltage generator 1, an alternating voltage generator 2, an adder 3c with three inputs, a power amplifier 4, a current pickup resistor unit 5, a sensor 6, a measuring amplifier 7, a driver 8, a phase detector 9, a recorder 10 controlled by a nonlinear inductance 11 and regulator 12. Generator outputs 1 and 2 are connected respectively to the first and second inputs of the adder 3. The output of the adder 3 is connected through a series-connected amplifier 4 and block 5 to the sensor 6. The inputs of the measuring amplifier 7 are dklyucheny to block 5 tokosnimayuschih resistors. The output of the measuring amplifier 7 is connected via the third output of the imaging unit 8 to the signal input of the phase detector 9, the reference signal input of which is connected to the generator 2. The output of the phase detector of the detector 9 is connected to the recorder 10. The imaging unit 8 is a DC amplifier with three outputs. The second output of the driver is connected via a controlled nonlinear inductance 11 with the sensor 6, and the first through the controller 12 is connected to the third input of the adder 3.

The voltamograph works as follows.

The polarizing voltage from the generators 1 and 2, formed in the adder 3, is amplified by power and through the block 5 current-removing resistors is applied to the electrodes of the sensor 6. The analyte solution, which is located in the sensor 6, flows the current determined by the superposition of voltages. A signal proportional to the current through the sensor b is amplified by the measuring amplifier 7 and fed through the driver 8 to the signal input of the phase detector 9. At

the reference input of the latter is supplied by the reference voltage from generator 2. The voltammogram is recorded by the recorder 10. Shaper 8 generates a signal applied to the nonlinear inductance 11, changing its inductance according to the law of the current-voltage characteristic. For each instantaneous value of the generator voltage 1 circuit, formed by a nonlinear inductance 11 and capacitance

Sensor 6 is tuned to resonance, so the capacitive current from the AC voltage is permanently compensated. From the third output of the imaging unit 8, the signal goes to the controller 12, where a signal is generated

. corrections that are subtracted from sensor current 6.

The magnitude of the inductance is determined from the resonance condition of the circuit formed with sensor 6.

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Claims (1)

Invention Formula A voltamperograph containing a linear voltage generator, an alternating voltage generator, an adder, a power amplifier, a current-sensing resistor unit, a sensor, a measuring amplifier and a phase detector with a recorder, the outputs of a linear voltage generator and an alternating voltage generator are connected to the corresponding - to the corresponding inputs of the adder, the output of which is connected to the sensor through a series-connected power amplifier and a block of resistors to which the inputs are connected, measure a booster amplifier, and a reference input A phase detector is connected to an alternating voltage generator, characterized in that, in order to increase sensitivity, a shaper with three outputs is inserted into it, a controlled nonlinear inductance and a regulator, and the sum of the torus is provided with a third input, and the shaper input is connected to the output the amplifier, the first output of the driver through the regulator is connected to the third input of the adder, the second through a controlled nonlinear inductance is connected to the sensor, and the third is connected to the signal input of the phase de vector.