JPS6033044A - Device for measuring polarography electrode provided with temperature compensating function - Google Patents

Abstract

PURPOSE:To miniaturize an electrode provided with a temp. sensor by forming the electrode and temp. sensor into a monolothic construction and making a part of a power feed system to both in common. CONSTITUTION:A polarography electrode 1 and a diode 2 used as a temp. sensor are unitized to a small size. The detecting part formed in such a way is connected by a conductor 3 to measuring device. The measuring device is constituted of resistors 4 and 6, a DC voltage source 5, voltage amplifiers 7 and 8, an analog switch 9, a changeover signal generator 10, an A/D converter 11, a CPU12, a memory 13 etc. The device is so arranged that the impressed voltage of the electrode 1 is generated at both terminals of the diode 2. The input of the amplifier 8 depends on temp. according to the temp. characteristics of the diode 2 and therefore the temp. of the electroe 1 can be detected. The miniaturization of the electrode provided with the temp. sensor is thus made possible.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to an electrode based on the principle of polarography, and particularly to an electrode measuring device having a temperature correction function suitable for electrodes placed in a living body.

[Background of the invention]

Conventional temperature correction for polarographic electrodes involves placing the temperature sensor separately alongside the electrode, or simply incorporating the temperature sensor into the electrode, which requires two power supply systems, resulting in a large overall size and The disadvantage is that it is highly invasive when inserted into the body.

[Purpose of the invention]

The purpose of the present invention is to provide an electrode with a temperature correction function that is less invasive to living organisms by making the electrode and the temperature sensor into an integrated structure, and by making a part of the power supply system common to both, thereby miniaturizing the electrode with the temperature sensor. Our objective is to provide a measuring device.

[Summary of the invention]

The present invention is characterized in that the electrode and the temperature sensor share a part of the power supply thread, have an integrated structure, and utilize a part of the electrode as a temperature sensor.

[Embodiments of the invention]

Embodiments of the present invention will be described below with reference to FIGS. 1 and 2.

In FIG. 1, polarography tk1. ! =The diode 2 used as a temperature sensor is compact and integrated. This detection part is connected to the measuring device by 4 wires 3. The measuring device includes resistors 4 and 6, DC voltage source 5, voltage amplifiers 7 and 8, analog switch 9, and switching signal generator 10.
．． 11 A/D converters 11% CPU12. It is composed of a memory 13.

Next, the operation of this circuit will be explained. The voltage applied to the polarographic electrode 1 is generated across the diode 2. Since the input of the voltage amplifier 8 depends on the temperature due to the temperature characteristics of the diode, the temperature of the polarographic electrode 1 can be detected. On the other hand, since the voltage variation due to temperature between both ends of the diode is sufficiently small compared to the voltage between both ends, the voltage applied to the polarographic electrode can be regarded as constant. The output current of the polarographic electrode, which is proportional to concentration or pressure, is converted into a voltage by a resistor 6 and input to a voltage amplifier 7. The outputs of voltage amplifiers 7 and 8 are switched by an analog switch 9 based on a signal from a switching signal generator 10 and input to an A/D converter 11. The temperature characteristics of the diode are stored in the memory 13, and when the temperature of the polarographic electrode changes, its output changes to C.
It is corrected by PU12. Although a diode has been shown as an example above, other temperature sensors such as a thermistor are also possible.

Next, the embodiment shown in FIG. 2 will be explained. In addition to the silver electrode 14 and the platinum electrode 15, the polarographic electrode is composed of an electrolytic solution, a polymer membrane, an immobilized enzyme membrane, etc. depending on the object to be measured, but only the silver and platinum electrodes that are common to all polarographic electrodes are shown. . The platinum electrode 15 is miniaturized to have a resistance value of about 1000, and serves not only as a part of the polarographic electrode but also as a platinum-side temperature resistor and a 1PAli sensor. This polarograph-f-
The it pole is connected to the measuring device by a conductor 3. The three resistors 16 constitute a bridge with the platinum electrode 15. In addition to the three resistors, the measuring device includes DC voltage sources 17 and 18, a differential amplifier 19, a resistor 20, a voltage amplifier 7, an analog switch 9, a switching signal generator 10%, an A/D converter 11% C
PU12. It is composed of a memory 13. A DC voltage source 17 is applied to the graph electrode 20, and a current proportional to the amount to be measured flows, which is converted into a voltage by the resistor 20 and input to the voltage amplifier 7. When the temperature of the polarographic electrode changes, an unbalanced voltage is generated across the bridge and is input to the differential amplifier 19. The output of this differential amplifier and the output of voltage amplifier 7 are input to analog switch 9, and thereafter the same processing as in the embodiment of FIG. 1 is performed. Here, although a DC voltage source is used for the voltage 18 applied to the bridge, it is also possible to use an AC voltage source. In that case, a circuit that generates a DC voltage proportional to the amplitude of the AC signal may be inserted between the differential amplifier 19 and the analog switch 9.

〔Effect of the invention〕

According to the present invention, the polarographic electrode and the temperature sensor can be integrated into an integrated structure, and a part of the power supply system for both can be made common, so the polarographic electrode with the temperature sensor can be miniaturized, and the polarographic electrode with the temperature sensor can be made smaller and less invasive to the living body. This has the effect of making it possible to configure a measurement system with less noise.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the configuration of one embodiment of the present invention, and FIG. 2 is a diagram showing the configuration of another embodiment of the invention.

Claims (1)

[Claims] 1. In a concentration or pressure measuring device consisting of a polarographic electrode and a measuring circuit, an integrated structure of the electrode and the temperature sensor incorporated therein, and a detection circuit that shares part of the electrical connection system between the electrode and the temperature sensor are provided. This is a polarographic electrode measuring device with temperature compensation function.