JPH11316204A - Cell for liquid analyser - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid analyzing cell capable of reducing a liquid sump after the drain of a liquid in a sample housing chamber. SOLUTION: In a liquid analyzing cell wherein the lateral opening 3 of a sample housing chamber 2 is sealed by the O-ring fitted in the annular groove 4 formed to the outer periphery of the opening 3 to be covered with a cell lid 6 and the O-ring guide 7 for guiding the fitted O-ring is provided, the lower part of the O-ring guide 7 is cut into an arc shape and the inner surface of the housing chamber 2 is polished.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cell for a liquid analyzer, for example, an acid meter for measuring the acidity of juice such as citrus fruits such as oranges and grapefruits and other acidities from the conductivity of a diluted sample. The measurement cell used in the above.

[0002]

2. Description of the Related Art For example, in an acid sugar content analyzer as a liquid analyzer, a housing contains a sugar content meter and an acid content meter located upstream of the sugar content meter. Then, a fruit juice including citrus fruits such as tangerines and grapefruit is used as a sample, and the sugar content is measured from the refractive index of the sample by injecting the sample into a measuring cell of a refractometer with an injector.After this measurement, the sugar content is measured. The acidity is measured from the conductivity of the diluted sample by feeding a sample obtained by adding dilution water to the measurement cell of the acidity meter.

As shown in FIGS. 7 and 8, a measuring cell 70 used for measuring the acidity has an accommodation chamber 7 for accommodating a sample.
The first side opening 72 is formed in a circular shape when viewed from the front.
An annular groove 73 is formed on the outer periphery of 2. Then, the side opening 72 is inserted into the O-ring 7 fitted in the annular groove 73.
The O-ring guide 76 that guides the O-ring 74 fitted therein is provided over the entire circumference inside the annular groove 73 while being covered with the cell lid 75 in a state sealed with 4. In order to obtain a predetermined diluted sample and measure the conductivity of the sample, the measuring cell 70 has a liquid introduction unit 77 and a discharge unit that discharges the sample by opening the solenoid valve after the measurement. 78, an insertion portion 80 for inserting a stirring blade 79 for stirring the sample in the storage chamber 71 by driving the motor M, a liquid level detection sensor insertion portion 81, and an overflow portion 82 connected to an overflow tank. Temperature sensor insertion part 83
And a conductivity sensor insertion portion (not shown).

[0004]

By the way, after the measurement,
Although the sample in the storage chamber 71 is drained by a natural fall from a drain port 84 formed at the back of the bottom of the storage chamber 71, since the measurement cell 70 is a resin molded product such as vinyl chloride, for example, The inner surface has roughness, and when the side opening 72 is covered with the cell lid 75, the lower portion 76a of the O-ring guide 76 provided around the entire circumference inside the annular groove 73 is caught. Due to the surface tension of the liquid (residual liquid of the sample) S (see FIG. 6), the accommodation chamber 7
For example, a liquid pool of an average of 0.3 to 0.4 ml was generated in 1. Therefore, the repeatability of the indicated value tends to be accidentally deteriorated due to the influence of contamination.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances, and has as its object to provide a cell for a liquid analyzer which can reduce a liquid pool after drainage in a storage chamber for storing a sample. It is.

[0006]

In order to achieve the above object, according to the present invention, a lateral opening of a storage chamber for storing a sample is provided.
In a liquid analyzer cell provided with an O-ring guide for guiding the O-ring fitted while covering with a cell lid while sealing with an O-ring fitted into an annular groove formed on the outer periphery of this opening. The lower part of the O-ring guide is cut into an arc shape, and the inner surface of the storage chamber is polished.

[0007]

Embodiments of the present invention will be described with reference to the drawings. 1 to 4 show one embodiment of the present invention. In this embodiment, a measurement cell of an acidity meter housed in an acid sugar content analyzer will be described.

1 to 4, reference numeral 1 denotes a measuring cell of an acidity meter A, for example, a cell body 30 which is a transparent resin molded product such as vinyl chloride, and a cell which is also a transparent resin molded product such as vinyl chloride. Lid 6 and sample (diluted fruit juice including citrus fruits such as tangerines and grapefruit with water)
And an agitating section 31. The cell body 30 has a storage chamber 2 for storing a sample. The side opening 3 of the storage chamber 2 is formed in a circular shape when viewed from the front, and an annular groove 4 is formed on the outer periphery of the opening 3. Then, the side opening 3 is covered with a cell lid 6 (for example, a transparent resin molded product such as vinyl chloride) in a state where the side opening 3 is sealed with an O-ring 5 fitted into the annular groove 4, and the O-ring fitted therein is also provided. 5
Is provided inside the annular groove 4.

In the present invention, two measures are taken to reduce the liquid pool after drainage. One of them is
The point is that the lower portion of the O-ring guide 7, that is, the lower portion 76a of the conventional O-ring guide 76 is cut into an arc shape. That is, the O-ring guide 7 is, for example, a conventional O-ring shown in FIG.
About 1/3 of the ring guide 76 is cut into an arc shape. As described above, since the catching portion that generates the surface tension of the liquid is eliminated, after draining, the surface tension of the liquid S as in the conventional case shown in FIG. 6 disappears, and the state shown in FIG. Is eliminated.

[0010] In the acid-sugar content analyzer, as shown in FIG. 5, a housing 8 contains a sugar content meter B and an acidity meter A located downstream of the sugar content meter B. Then, the sugar content is measured from the refractive index of the sample by injecting the sample into the measuring cell of the refractometer B with an injector. In this case, a valve 40 connected to the overflow tank 18 is provided between the acidity meter A and the sugar meter B, and the sugar content is measured by, for example, injecting a sample to the overflow tank 18 by a single sample injection of about 5 ml. After this measurement, the valve 40 is switched by the switching motor M ₁ and the sample measured by the valve 40 plus the dilution water from the dilution water tank 9 is sent to the measurement cell 1 of the acidity meter A. The acidity is measured from the conductivity of the diluted sample.

In this case, a predetermined diluted sample is obtained,
In order to measure the conductivity of the sample, the cell body 30 of the measurement cell 1 is provided with the liquid introduction unit 10 and the sample after the measurement, for example, by opening the pinch valve 11.
For example, an insertion part 13 for discharging a liquid from a liquid discharge port 13a formed at the back of the container, to which a silicon pipe 12 is connected, and a stirring blade 14 for stirring the sample in the storage chamber ₂ by driving a motor M2. and parts 15, a sensor insertion portion 17 of the liquid level detection sensor 16, an overflow portion 19 connected to the overflow tank 18 (see FIG. 5), a sensor insertion portion 20 of the temperature sensor T _2, the sensor conductivity sensor 21 The insertion portion 22 and the cell body 30 are connected to the chassis 23 in the housing 8.
A screw hole 25 into which a screw 24 is inserted to fix the cell cover 6 upward (see FIG. 2), and a screw hole 2 into which a screw 26 is inserted to fix the cell lid 6 so as to cover the side opening 3.
7 are provided. The drainage of the sample after measurement is
The liquid is naturally dropped from the drain port 13a formed at the back of the bottom G of the storage chamber 2. In order to efficiently discharge the liquid, the lower surface V of the cell body 30 and the fixing surface W of the chassis 23 are used. The surface F facing the side opening 3 of the cell main body 30 is formed so as to be inclined so that the angle θ formed by the angle is slightly larger than 90 °.

[0012] The stirring unit 31 is fixed to the vertically movable chassis 23 by a long hole 33 and screw 34 provided on the motor M ₂ mounting plate 35, when the wiping accommodating chamber 2 inside the cleaning and the Then, the stirring blade 14 can be taken out of the storage chamber 2 through the stirring blade insertion portion 15.

A second means for reducing the liquid pool at the time of drainage is to use, for example, a gel-like acrylic abrasive for the roughness on the inner surface of the housing chamber 3 and use a polishing cloth for the housing chamber. 3 is that the inner surface is polished.

According to the present invention, for example, a gel-like acrylic abrasive is used for the roughness of the inner surface of the storage chamber 3 and the inner surface of the storage chamber 3 is polished for about 10 minutes with a polishing cloth. Was done. As a result, what was 5 μm or more before polishing became 3 μm or less after polishing, and the slip was improved. Further, according to the present invention, the lower portion of the O-ring guide 7 is cut into an arc shape, thereby preventing the occurrence of surface tension of the liquid.

For this reason, after the liquid is drained from 13a by natural fall, for example, an average of 0.3
Although liquid pools of up to 0.4 ml of the sample occurred, in the present invention, the liquid pool of the sample in the storage chamber 2 could be reduced to, for example, an average of 0.05 ml or less.

For example, when 14 g of KCl is put into orange juice and diluted with water to adjust the acidity to about 5 wt%, a sample is prepared using a measuring cell 70 of a conventional acidity meter.
As shown in Table 1 below, the indicated values in ten consecutive measurements near the high concentration side (5 wt%) tended to shift accidentally, and the error (%) of the shift was -2%. Against
As shown in Table 1 below, in the measurement cell 10 of the acidity meter of the present invention, there was no deviation in the indicated value in ten consecutive measurements near the high concentration side (5 wt%). That is, according to the present invention, the deviation error (%) was reduced to 0%.

[0017]

[Table 1]

[0018]

As described above, since the lower portion of the O-ring guide is cut into an arc shape and the inner surface of the storage chamber is polished, the liquid pool of the sample in the storage chamber after drainage is reduced. Can be reduced. That is, it is possible to solve the conventional problem in which a liquid pool occurs and is affected by contamination, whereby the repeatability of the indicated value tends to be accidentally deteriorated.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view showing an embodiment of the present invention.

FIG. 2 is a configuration explanatory view showing an attached state in the embodiment.

FIG. 3 is an explanatory diagram of a main part configuration in the embodiment.

FIG. 4 is a diagram for explaining an operation in the embodiment.

FIG. 5 is an explanatory diagram of the entire configuration showing an example of a cell for a liquid analyzer.

FIG. 6 is a diagram for explaining a problem of a conventional example.

FIG. 7 is a configuration explanatory view showing a mounting state of a conventional example.

FIG. 8 is an explanatory diagram of a main part configuration in a conventional example.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Measurement cell, 30 ... Cell main body, 2 ... Housing room, 6 ... Cell lid, 3 ... Side opening, 4 ... Annular groove, 5 ... O-ring, 7 ... O
Guide for rings.

Claims (1)

[Claims] 1. A side opening of a storage chamber for storing a sample is covered with a cell lid in a state of being sealed with an O-ring fitted in an annular groove formed on an outer periphery of the opening, and the O-fitted is fitted therein. In a liquid analyzer cell provided with an O-ring guide for guiding a ring, a lower portion of the O-ring guide is cut into an arc shape, and an inner surface of the storage chamber is polished. Liquid analyzer cell.