CS231860B1 - Compact Polarographic Analyzer - Google Patents

Abstract

The invention relates to a compact polarographic analyzer, comprising a measuring instrument and a sensor - a static mercury drop electrode. The essence of the invention lies in the fact that in its circuit, a control block containing digital memories of the PROM, EPROM, ROM type is connected to a polarization voltage generator block, including a polarization pulse and a potentiostat, an analog memory block and amplifiers for the mercury valve solenoids and a mechanical drop separator.

Description

The present invention provides an analytical instrument, a compact polarographic analyzer, comprising a measuring instrument and a sensor-mercury droplet electrode.

So far, there are two manufacturers, PARC and k.p. Laboratory instruments that complete the polarographic analyzers with a static mercury drop electrode, a new type of sensor that allows measurement on a fixed surface of a mercury drop controlled by an electronically controlled valve.

Polarographic analyzer and static mercury drop electrode are two separate devices with technical and economical disadvantages resulting from this: greater space requirements, higher material consumption for cabinets, use of two separate power sources including transformers, unfavorable influence of interconnection between devices in terms of electromagnetic interference and especially the necessity synchronization of two separate control blocks generating polarization pulses and control pulses for sampling current and control pulses for controlling the lip valve 6 and the droplet separator.

The described arrangement has its historical origin in the traditional connection of the polarograph with the classical drop electrode, which was purely mechanical device. These disadvantages are eliminated by a compact polarographic analyzer comprising a static mercury drop electrode and a polarographic analyzer in a single instrument, in which the control block comprising the PROM, EPROM, ROM digital memories is connected to the polarization voltage generator block, including the polarization pulse. and a potentiostat, an analogue memory block, and amplifiers for mercury valve solenoids and a mechanical droplet separator.

The attached drawings show block diagrams of two realized versions of the compact polarographic analyzer. Fig. 1 is a diagram of a version of a compact polarographic analyzer intended for universal laboratories and educational purposes.

Figure 2 is a block diagram of a routine version of a compact polarographic analyzer. The control block 8, consisting of a former, a digital divider, gates and digital memories of the PROM type, is connected to a block 6 of a polarizing voltage generator consisting of an analog integrator and an adder where the polarizing pulses generated by the control block 6 are added.

It is connected to the control block 1 by means of a switch 10, which selects the mercury flow time and hence the mercury drop size, an amplifier 6 in the output of which a solenoid valve 6 for mercury 6 is connected and an amplifier 5 for a mechanical droplet separator 6.

In addition to the outputs of the control block 8, a drop time selection switch 11 and a switch 12 for selecting a tapping or hanging mercury drop are connected. A block 13 for selecting the rate of rise of the potential, a potentiometer 14 for selecting the initial potential, and a switch 15 of the polarization pulse amplitude are connected to the outputs of the block 6.

A working mercury electrode 21, an auxiliary electrode 22 and a reference electrode 23 located in the vessel 24 are supplied from the potentiostat included in the block 6. The polarization voltage generator block 6 is followed by a current amplifier block 6 in which it switches from the pore, ie current ranges, switch 16.

The output of the analogue memory block 6 is connected to the output of the block 6, followed by the output amplifier block 6 with a potentiometer 17, compensating the bias current in the summation input. An external amplifier 19 can be connected to the output of the block.

A switch 18 for selecting the operating modes DC, TAST, NP, DPP is connected to the control inputs of the control block. In the block diagram of the routine version, block 20, the switch for the combined selection of polarization voltage, polarization pulse amplitude, and operation mode are connected to the control inputs of control block 6.

An important economic advantage of the described devices is, besides saving material for cabinets, transformers and other elements, necessarily doubled in the usual arrangement into two devices, especially the realization of a single control block controlling elements belonging to the static mercury drop electrode and polarographic analyzer.

This allows the production cost of the device to be reduced to about 2/3 of the cost of a traditional combination. Moreover, the implementation of the routine version in the set of two devices is difficult to realize by the introduction of electronically operated switches for the functions of the static mercury drop electrode.

The described arrangement allows significantly better suppression of interfering signals by limiting the free conductors for the control pulses and especially by better shielding the conductors in the measuring circuit, which can be installed inside the housing of the device.

Claims (1)

SUBJECT OF THE INVENTION A compact polarographic analyzer comprising a static mercury drop electrode and a polarographic analyzer in a single instrument, characterized in that the control block (1) containing the digital memories of the PROM, EPROM or ROM type is connected to the polarization voltage generator block (2), including the polarization pulse. block (3), analog memories and amplifiers (4 and 5) for the solenoid valves (6) on the mercury and the mechanical ripper (7).