CN2336358Y

CN2336358Y - Ion-selective electrode

Info

Publication number: CN2336358Y
Application number: CN 98226471
Authority: CN
Inventors: 仓东卿; 张秀成
Original assignee: Institute of Soil Science of CAS
Current assignee: Institute of Soil Science of CAS
Priority date: 1998-04-13
Filing date: 1998-04-13
Publication date: 1999-09-01
Anticipated expiration: 2008-04-13

Abstract

The utility model discloses an ion-selective electrode, which is composed of an external cavity body, an internal reference solution, an internal reference electrode, a sensing head, an electrode cap, a shielding conductive wire and a shielding plug; the sensing head is composed of an internal cavity body and a sensing film; the other end of the inner cavity body is fixed at the upper opening position of the external cavity body; the sensing film forms a concave shape structure with the internal cavity body, and the sensing film is arranged at the bottom position in the concave shape structure. When the utility model is used, the tested solution can be directly injected in the concave shape structure, and thus the tested solution can be measured only in minute quantity.

Description

Ion-selective electrode

The utility model belongs to the method test of electricity consumption, galvanochemistry or magnetic or the technical field of analysis of material, and the sensing head that relates to a kind of ion-selective electrode, particularly a kind of electrode adopts the ion-selective electrode (G of special construction ₀₁N _27/30).

Ion-selective electrode is a most widely used gang electrode in the chemical sensor field, and they have been widely used in technical fields such as industry, agricultural, environmental protection and medical science.Outside sensitive membrane on the sensing head of the ion-selective electrode that past people is generally used all is exposed to, for example ion-selective electrode is the occasion of glass electrode, sensitive membrane on its sensing head is made usually such as shapes such as blistered, tabular or tapers, and reference solution and internal reference electrode all are arranged on the electrode stem inside of this electrode in it.This class electrode in actual use, the sensitive membrane of electrode sensitive head position and contrast electrode salt bridge tip all directly must be immersed solution to be measured and reach certain degree of depth, measurement is carried out smoothly, so it is more to measure used sample size at every turn, and since its sensing head on sensitive membrane be exposed to outside, therefore the impaired phenomenon of sensitive membrane also takes place often, be under the situation of glass electrode particularly in ion-selective electrode, the impaired phenomenon of sensitive membrane is particularly seriously in order to reduce amount of samples, once the electrode sensitive film was made tabular or miniature, though this measure can make amount of samples reduce to some extent, but the electrode internal resistance significantly increases thereupon, not only strengthened measuring error, also caused difficulty with the instrument impedance matching

The purpose of this utility model is to provide a kind of sensing head to adopt the ion-selective electrode of special construction, to overcome existing defective and deficiency in the above-mentioned prior art

Task of the present utility model is finished in the following manner, a kind of ion-selective electrode, by outer chamber, interior reference solution, internal reference electrode, sensing head, electrode cap, shielded conductor and shielded plug constitute, its key is that above-mentioned sensing head is made of inner chamber body and sensitive membrane, the other end of inner chamber body is fixed on the position of upper of outer chamber, and sensitive membrane and inner chamber body constitute concave structure, and sensitive membrane is in the basal surface position of this concave structure internal orifice

The above-mentioned concave structure that constitutes by sensitive membrane and inner chamber body, formed the cavity of a splendid attire solution to be measured, because inner chamber body is in the inside of outer chamber, therefore sensitive membrane also must be in the inside of outer chamber, in case solution to be measured is injected among this cavity, being about to solution to be measured injects among the sensing head that is made of sensitive membrane and inner chamber body, solution to be measured must be in the position of sensitive membrane, insert small-sized contrast electrode in the solution to be measured this moment again, can measure as seen solution to be measured, measure with this ion-selective electrode after improving, the solution to be measured that only needs minute quantity, and because sensitive membrane is in the inside of outer chamber, so the impaired phenomenon of sensitive membrane also will significantly reduce

Generally, sensitive membrane can be made blistered.In order further to reduce the consumption of solution to be measured, also sensitive membrane can be made various required shapes such as tabular or taper, this can select according to different request for utilizations fully.

In ion-selective electrode is under the situation of glass electrode, in order to solve the transition problem of internal reference electrode and glass, the type of attachment of above-mentioned internal reference electrode and shielded conductor can adopt scheme commonly used in the prior art, and promptly internal reference electrode is connected with shielded conductor with Dumet wire via platinum filament.

In ion-selective electrode is under the situation of glass electrode, preferably set up one deck shielded film in the interlayer of electrode outer chamber and electrode cores again, can avoid the interference of external electric field like this, further improve the measurement performance of ion-selective electrode, so that obtain accurate measurement result

Only is that example is illustrated below by accompanying drawing shown in the embodiment with the glass electrode to the version that the utility model is described in further detail sensing head, but the sensing head of other ion-selective electrode all can adopt this kind version.

Fig. 1 is the one-piece construction diagrammatic cross-section of the glass electrode of sensing head after improving;

The diagrammatic cross-section of the sensing head that Fig. 2 is constituted for hemisphere blister sensitive membrane and inner chamber body;

The diagrammatic cross-section of the sensing head that Fig. 3 is constituted for tabular sensitive membrane and inner chamber body;

Fig. 4 is the diagrammatic cross-section of the sensing head that trapezoidal sensitive membrane and inner chamber body constituted;

The diagrammatic cross-section of the sensing head that Fig. 5 is constituted for taper sensitive membrane and inner chamber body

With reference to Fig. 1, the suitable for reading of suitable for reading and inner chamber body 2 of glass electrode outer chamber 1 is sintered into one, and the lower end of inner chamber body 2 is sensitive membrane 3, inner chamber body 2 and sensitive membrane 3 have constituted the sensing head of electrode, sensitive membrane 3 is actually one deck sensing glass film, and in the present embodiment, sensitive membrane 3 is made into the hemisphere blister.Sensitive membrane 3 constitutes concave structure with inner chamber body, this concave structure has formed the cavity of a splendid attire solution to be measured, because sensitive membrane 3 is in the basal surface position of this concave structure internal orifice, in case solution to be measured is injected among this cavity, promptly in a single day solution to be measured is injected by among the sensing head that sensitive membrane and inner chamber body constituted, solution to be measured must be in the position of sensitive membrane 3.Internal reference electrode 4 is fixed on the nearly middle position of outer chamber 1 inside through electrode core body 5, by outer chamber 1, inner chamber body 2, reference solution 6 in being filled with in the airtight cavity that sensitive membrane 3 and electrode cores 5 form, internal reference electrode 4 is connected with shielded conductor 9 through platinum filament 7 and Dumet wire 8, shielded conductor 9 is outwards drawn through electrode cap 10, electrode cap 10 is fixed on the following oral of outer chamber 1 and it can also be seen that from Fig. 1, also have additional one deck shielded film 11 between electrode cores 5 and the outer chamber 1, promptly at internal reference electrode 4, the outside of platinum filament 7 and Dumet wire 8 is coated with one deck shielded film 11.

With reference to Fig. 2, Fig. 3, Fig. 4 and Fig. 5, at the end opening position of inner chamber body 2, sintering has difform sensitive membrane 3 respectively, so that satisfy different request for utilizations.

The ion-selective electrode that the new shape of this practicality is provided is when reality is used, because in the concave structure that solution to be measured can directly inject its sensitive membrane and inner chamber body to be constituted, be that solution to be measured can directly inject in the sensing head that is made of sensitive membrane and inner chamber body, so only need the solution to be measured of minute quantity to measure;

Because sensitive membrane is in the inside of outer chamber, so can effectively avoid the impaired phenomenon of sensitive membrane on the sensing head, has prolonged the serviceable life of ion-selective electrode

Claims

1, a kind of ion-selective electrode, constitute by outer chamber, interior reference solution, internal reference electrode, sensing head, electrode cap, shielded conductor and shielded plug, it is characterized in that above-mentioned sensing head is made of inner chamber body and sensitive membrane, the other end of inner chamber body is fixed on the position of upper of outer chamber, sensitive membrane and inner chamber body constitute concave structure, and sensitive membrane is in the basal surface position of this concave structure internal orifice.

2,, it is characterized in that being shaped as of above-mentioned sensitive membrane is blistered, hemisphere blister, tabular, trapezoidal or taper according to the ion-selective electrode of claim 1 regulation.

3, according to the ion-selective electrode of claim 2 regulation, it is characterized in that above-mentioned internal reference electrode is connected with shielded conductor with Dumet wire via platinum filament

4,, it is characterized in that having additional one deck shielded film in the interlayer of above-mentioned electrode outer chamber and electrode cores according to the ion-selective electrode of claim 1,2 or 3 regulations