JPH06506060A - Electrode adjustment - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] Electrode adjustment The present invention relates to an electroanalytical detection instrument having a plurality of sensor probe electrodes, particularly an electrode Concerning how to adjust and use.

When measuring active electrochemical substances using a potential difference, i.e. electrolyte (analyte) When measuring the voltage between electrodes in a medium, first, a standard solution or buffer solution with known activity Adjust the instrument inside, collect the slope voltage and offset voltage, and use it for subsequent measurements. It is essential that These voltage values are transferred to an analog potentiometer in the circuit of the measuring instrument. or, if the instrument is digital, store it in a storage device.

After adjustment, either the separable indicator electrode and the reference electrode, or a combination Multiple measurement electrodes in parallel pairs can be used without removing and readjusting the instrument. However, it cannot be connected to another device in another location.

Therefore, the present invention provides for the adjustment and measurement of such sensors in one place or in one instrument. , on another device, or on another location. be.

The present invention also has the potential to be used with any type of sensor that requires reconditioning. It concerns the problem of providing a device for the future.

The voltage measured using potentiometric electrochemical sensors is primarily analyte dependent. , is known to be expressed by the following Nernst equation.

E (measurement) [=E (indicator electrode half cell) - E reference where, E (electronic ea half sy) = E’ (ms) + (rr/nF) -In (A m) E Standard: E (base half cell) + E (potential of bonding part )A@ is the activity of species A and is approximately equal to the concentration of A in the diluted solution.

Under normal circumstances, the reference half-cell and junction potentials can be unpredictable by more than a few millivolts. possible and can differ significantly between different reference electrodes. concentration, or I In order to directly measure n (concentration) using an instrument, first, many standard solutions must be It is necessary to convert the measured millivolts by adjusting the system accordingly. It is essential. Theory - The difference between Milliport of L and the measured value is the offset for that particular system. is the cut voltage. This voltage is measured using a potentiometer and theoretically milliports value, or use a microprocessor and storage device for later use. and store it digitally in the measuring instrument.

In a complete system, the measured milliport is proportional to the logarithm of the analyte activity. Give an example. From Nernst's equation, it can be seen that this becomes:

(RT/nF)・In (Am) or 2.303- (revised/nF) log (A 11) at a temperature of 25°C , the value is 59.13 mV per IO unit (decade) increase in concentration. Ru.

In practice, this theoretical factor is rarely obtained (and instead, the standard Empirical factors are calculated from adjustment data obtained by measuring quasi-solutions. This fa When measuring a standard solution, the gain of the input circuit can be set and used later. Store it in the analog instrument as you get it. In microprocessor equipment, this is stored directly in the storage device as one 7 actor. This factor It is defined as the slope of the system and can be expressed as a percentage.

As mentioned above, when measuring active electrochemical substances using potential difference, the first step is to measure active electrochemical substances. Adjust the voltage in a standard solution or buffer solution with known properties, and adjust the slope voltage and offset voltage to the desired value. Therefore, it is essential to use it for subsequent measurements.

According to the invention, the adjustment data is based on the electrodes or electrical The adjustment device is stored in close physical association with the pole pair assembly. this thing The electrode assembly and adjustment device can be removed from the instrument and moved to a remote location. It means something. New instruments read this information and require no readjustment. , the measurement is ready.

The invention therefore provides at least one measuring electrode and a storage device associated with the electrode. and an electrode assembly connected to an electroanalytical detection instrument comprising: , the storage device is configured to allow for use of the assembly with multiple detection instruments. It is arranged so that it can store regular data.

This solution allows a single indicator electrode and a pair of reference electrodes to be placed in the laboratory or in a It can be prepared in a clean place, and for measuring solutions, buffers or standard solutions can be used. This means that they can be moved into potentially contaminated factory environments.

The assembly according to the invention includes a microprocessor device as well as electrodes or probes. includes a small storage and communication integrated circuit sealed in either of the holder assemblies. This is desirable. The electrode pair is prepared using a buffer solution or a standard solution using a conventional method. Adjustment data such as ramp voltage and offset voltage can be transmitted via a series communication link. The data can be stored in the storage means within the electrode pair via the link. Then this information is , for later availability, e.g. battery-assisted RAM, EPROM or It can be stored in a non-volatile storage device such as EEPROM. Next, the electrode You can disconnect it, move it to a new location, and connect it to another device. This new The instrument retrieves this adjustment data and is ready to take measurements.

Time of adjustment, other information about safe time available before readjustment, identification number and the type of electrode can be memorized.

The storage means is also conveniently incorporated into the lead assembly of existing electrode systems.

Also, in places where the impedance of the electrode is large or the measuring instrument is very far from the electrode. If there is a possibility that the storage means may be installed in a edrivers) or multiple impedance converters. .

Additionally, electrode assemblies according to the invention are inherently safe where flammable solvents are used. It is possible to make it so that Next, adjust the water bath and related equipment safely. This can be done at any normal available location. Next, measure the electrode assembly Connections to the appliance are made via a short-circuit-diode safety barrier. It is desirable that

In the following, with reference to the accompanying drawings: - some embodiments of the invention by way of example; explain. In the attached drawings, FIG. 1 is a schematic diagram of the indicator electrode with the adjustment device installed, FIG. FIG. 3 is a schematic diagram of a combined pair of electrodes fitted with a regulating device; is a schematic diagram of a sensor probe with an adjustment device mounted on a corner device separate from the sensor. schematic diagram, FIG. 4 is a schematic diagram of an electrode system with a regulating device installed in the conductor; FIG. 5 is a block circuit diagram of the adjustment device, and FIGS. 6a to 6e illustrate the present invention. 1 is a diagram of various known electrodes that can be used.

FIG. 1 shows an indicator electrode incorporating an adjustment device. cylindrical gala A gas container 1 supports an electrode thin film 2 at its lower end and holds an electrolyte 3. The thin film 2 is A conductive wire 4 connects it to a shielded multi-strand output wire 5 .

The conducting wire 4 is shielded by a metal shielding sheath 6. This is illustrated in the schematic diagram However, in reality, inside the electrolyte 3, there are concentric glass inner walls and outer walls. It can be placed between.

The glass container 1 is supported by a carrier 7 on top of the electrode assembly, and the glass container 1 is supported by a carrier 7 on top of the electrode assembly. The solid supports the container 1 and wraps around the wires extending into the multi-core cable 5.

The carrier 7 also has an adjustment device whose output conductor is connected to the multi-strand cable 5. Wraps f18.

The electrode is used in conjunction with a reference electrode that forms part of a control pair of electrodes. reference electrode The notable difference is that the porous wall is used instead of the thin electrode film 2 where the voltage is generated. The reference electrode is used at its lower end, so that the reference electrode is obtained from the solution within the electrode. , therefore it is held at a constant potential. The adjustment data is related to the indicator electrode. while the adjustment also takes into account variations within the reference electrode. . Therefore, a particular reference electrode always has the same indicator identified and adjusted. Must be used with electrodes.

FIG. 2 essentially shows the structure shown in FIG. 1 in combination with a surrounding reference electrode. A combination electrode consisting of measuring electrodes of various types is shown.

Components that are the same as those in the embodiment of FIG. 1 are designated by the same reference numerals, and these components are approximately the same. However, the enclosing glass jacket 10 surrounds the measurement electrode. This forms a reservoir of reference solution 11 within the annular compartment.

Inside the reference solution 11 there is a reference element 12, the lower surface of the circular jacket 1o is It is closed with a porous annular frame 13. In this way, the reference element is exposed to the reference solution. It is possible to maintain a constant potential determined by

This means that the difference between the liquids on both sides of the sensing element 2 (such as for measuring Ph) is In order to detect this, a glass thin film [2] is used to This is in contrast to the case of a constant electrode. This reference element 12 is then connected to the It is connected to a chemical cable 5 of several strands.

A further configuration is illustrated in FIG. In this configuration, the measurement electrode 20 and a reference electrode 21 (of the shape approximately shown in FIG. 1) is connected to the main carrier 7. It is provided in the connection carrier 22. These two electrodes 20.21 and the ground terminal 22 is connected by conductor 23 to output amplifier 25 via plug and socket 24, and thus , connected to a multi-strand cable 5 for powering the appliance (not shown).

FIG. 4 illustrates yet another form of the invention, in which the combined electrical The pole 31 is powered by a conductor 32 via a regulating device 8 to an instrument (not shown). , that is, the adjustment device is integrated into the conductor connecting the electrodes.

In each of the above embodiments, the regulating device 8 is always associated with one or both electrodes. This allows the or each electrode to be disconnected from the device and moved to another location. When moved to , the adjusting device will always be accurately adjusted.

FIG. 5 shows a schematic diagram of a particular form of adjustment device. This adjustment device A pair of operational amplifiers 41 and 42 with high pedance are provided, and the operational amplifiers are shown in the drawing. is input from the sensor via the input conductor on the right side of FIG. output to the output conductor. The regulating device is also connected via a series line drive 44.45. A capsule type battery and a storage device 4 are powered by a multi-strand cable 5. Built-in microprocessor with 3.

In this way, the pair of electrodes is actually adjusted and the adjustment results are stored in the storage device 43. memorized and the electrode can be used by connecting it to other instruments at different locations becomes.

The invention is applicable to many forms of known measurement electrodes. For example, in Figure 5, Regulating devices of the type indicated can be easily integrated into the output conductor or into the carrier head of the electrode. I can do it.

In this way, FIGS. 6a to 6e illustrate each of the areas to which the present invention can be applied. Seed electrodes are shown. These electrodes are as follows.

Figure 6a shows a metal electrode.

Figure 6 shows a coated metal electrode.

FIG. 6C shows an ion selective electrode.

Figure 6d shows a liquid ion exchange ion selective electrode.

Figure 6e is a pH electrode.

The components in these electrodes are as follows.

In FIG. 6a and FIG. While the poles are shown, in FIG. 6, the reference numeral 53 indicates the detection covering portion.

Regarding FIG. 6C, in the solid-state ion-selective electrode, reference numeral 55 indicates the solid thin film 54. The conductive contacts are shown.

In FIG. 6d, the liquid iron exchange ion-selective electrode 57 has an internal reference solution, symbol 58 is an internal reference element, while 56 is for generating a voltage across it. This is a detection thin film that can be used.

Finally, FIG. The glass body 60 has an internal reference solution 62 in it. It houses the element 61.

October 4, 1993 (

Claims (9)

[Claims] 1. Measuring instruments with multiple measuring sensors that require adjustment and multiple assemblies to store adjustment data to enable use with other detection instruments. an adjustment device having a storage means disposed in a close relationship with the plurality of sensors; measuring instruments. 2. The measuring instrument according to claim 1, wherein the plurality of sensors are of an electroanalytical type. A measuring device that is a plurality of measuring electrodes of a sensing device. 3. The measuring instrument according to claim 2, wherein the plurality of measuring electrodes are Ph electrodes. A measuring instrument. 4. The measuring instrument according to any one of claims 1 to 3, wherein the sensor comprises a carrier housing, and the adjustment device is arranged within the carrier housing. measurement tool. 5. The measuring instrument according to any one of claims 1 to 4, one of which is A pair of electrodes, the other being an indicator electrode and the other being a reference electrode, A measuring instrument in which a measuring device is associated with the indicator electrode. 6. The measuring instrument according to claim 5, wherein the indicator electrode and the reference A measuring instrument in which the electrodes are combined as a single unit. 7. The measuring instrument according to claim 1, wherein the adjustment device is configured to adjust the output of the sensor. A measuring device supported within a force conductor. 8. A measuring device substantially as described with respect to the accompanying schematic drawings. 9. Electrode used in the measuring instrument according to any one of claims 1 to 8 assembly.