JPS5935131A - Thermostatic flow cell - Google Patents

Abstract

PURPOSE:To achieve a highly accurate analysis with the inner wall of a passage hard to pollute while eliminating attached air by sandwiching a member for absorbing thermal expansion with a metal wall covering the passage of material to be measured made of glass and the border between the passage and the metal wall in a thermostatic flow cell. CONSTITUTION:A tube, a passage of material to e measured, composing a suction tube section 6, a measuring window section 8 and a drain tube section 9, is made of glass in a thermostatic flow cell 1 of particularly an automatic chemical analyzer. A thermal expansion difference absorbing member 9 of a highly heat conductive metal (low temperature silver solder or the like) covers the circumference of a metal wall 12 covering the passage and the border between the passage and the metal wall 12. A temperature control sensor 10 is buried close to the body 5 of the flow cell and both sides of thermoelectric elements 3 and 3 are brought into contact with the metal wall 4 separately through a thermal compound 11. This facilitates the holding of the flow cell body 5 at a constant temperature while minimizing irregularities of the inner surface of the tube of the body 5 thereby improving the measuring accuracy eliminating the attachment of contaminants and air bubbles.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a constant temperature flow cell, and particularly to a constant temperature flow cell that is most suitable for an automatic biochemical analyzer.

[Background technology and its problems]

In general, a thermostatic flow cell maintains the measured object stored in a predetermined container at a set temperature, but in an automatic biochemical analyzer, the measured object (for example, blood as a sample with reagents added to it) ) is needed to quickly raise the temperature to a predetermined temperature, thereby stabilizing the chemical reaction quickly and shortening the processing time, thereby improving the accuracy of measurement data. In order to meet such demands, for example, constant temperature flow cells have been used, in which a thermoelectronic element (for example, a Vertier element) is provided in the main body of the full cell, into which an object to be measured is poured and photometrically measured.

By the way, most of the surfaces of conventional constant-temperature flow cells, other than the window surface through which light must pass for measurement, are made of metal such as stainless steel, and in order to manufacture these constant-temperature flow cells, metal polishing and Advanced manufacturing technology such as microfabrication was required. On the other hand, if the processing accuracy is poor, there is a lot of residual contamination (cross contamination) of the object to be measured, and air bubbles (due to processing scratches, 9 burrs, etc.) are formed, resulting in a reduction in measurement accuracy.

In addition, with the progress of biochemical analysis in recent years, the number of measurement items for a wide variety of analytes has increased in automated biochemical analyzers. It was difficult to measure pressure due to metal ion precipitation.

〔the purpose〕

The present invention has been made based on the above circumstances, and it is possible to reduce residual contamination of the object to be measured, reduce adhesion of air, etc. to the uneven inner surface, and improve the accuracy of measurement data. Pressure can be easily measured even for measurement items such as metal ions that are difficult to measure with a metal flow cell, as well as measurement items that are harmful and corrode the metal flow cell.
The object of the present invention is to provide a constant temperature glass flow cell that is easy to manufacture.

〔overview〕

The present invention provides a high-pressure, constant-temperature flow cell that maintains a measured object at a constant temperature to achieve the above objects, in which a flow path through which the measured object flows is formed of glass, and a metal wall is provided to cover the outside of the glass flow path. , a member for absorbing the difference in thermal expansion between the glass and the metal (a material with good thermal conductivity) is placed at the boundary with the flow path.
It is characterized by the inclusion of.

〔Example〕

The constant temperature flow cell of the present invention will be explained below with reference to the drawings. Figure 1 is a partially cutaway cross-sectional view showing an embodiment of the constant temperature flow cell of the present invention. This is an example of what is used in an automatic biochemical analyzer of this type.

In the same figure, 1 is the flow cell main body, and this flow cell 1
A photometric window 2 is provided on the side surface of the photometer to allow the source for analysis to pass through, and a thermionic element 3.6 is attached to the other orthogonal surface via a thermal compound (not shown). At this time, if the signs of the charges supplied to the thermionic elements 3.3 are equal, the contact surfaces of the thermionic elements 6.6 that are in contact with both sides of the flow cell body 10 are unified into a part of the heating surface or cooling surface. are doing. And this thermionic element 3.
A heat dissipation plate 4 for transmitting heat to the thermionic elements 3 and 3 or dissipating the heat of the thermionic elements 6 and 3 is attached to the flow cell body 1 via the thermionic elements 3 and 3. The heat sink 4 also fixes a thermionic element 3.6 to the flow cell body 1. 6 is a suction pipe for filling the flow cell with the object to be measured, and 7 is a discharge pipe for discharging the object to be measured after measuring the object.

Next, referring to FIG. 2, the internal structure of the flow cell main body will be explained. Reference numeral 5 denotes a suction pipe 6 for filling the object to be measured in a glass flow cell, and a drain pipe 7 for discharging the object to be measured after measurement.
It has a measurement window 8. The outer periphery of the flow cell main body 5 is covered with a thermal expansion difference absorbing member 9 made of a metal with good thermal conductivity (for example, low-temperature silver), and the outer periphery of the flow cell body 5 is covered with a metal wall that also has good thermal conductivity (for example, low-temperature silver). , copper) 12.

A photometric window 2 is provided in a part of the metal wall 12 so as to communicate with the measurement window 8 of the flow cell body 5.

In FIG. 6, the inside of the cell main body 1 is located near the thermal expansion difference absorbing member 9 and near the center of the flow cell 5 in the optical path length direction, and as close as possible to the object to be measured. A control sensor 10 is embedded. Both sides of the thermionic elements 3 and 6 are brought into contact with the flow cell body 1 and the metal wall 4, respectively, via a thermal compound 11.

In the above configuration, its operation will be explained next.

The thermostatic flow cell having such a trap structure is used by being attached to an appropriate automatic biochemical analyzer (not shown). Before the object to be measured is sucked into the 7 μm cell 5 from the suction tube 6, the power source is turned on. As is well known, the Vertier element known as the thermionic element 3 has the Peltier effect, that is, two kinds of materials,
For example, this thermionic element utilizes the effect that when two types of metals and a conductor are joined together and a current is passed through them, heat other than Joule heat is generated or absorbed at the junction. Since the opposing surfaces of 6 are installed so that they are thermally similar (for example, the heating side and the heating side), the set temperature is stable. In this state, the object to be measured is sucked through the suction pipe 6 and is filled halfway into the flow cell 5 and further into the discharge pipe 7. When the temperature control sensor 10 determines that the temperature of the object to be measured is below the set temperature, it operates a control circuit (not shown) to operate the thermionic element 3 to heat the object. The heat generated by the thermionic element 6 is transferred to the thermal compound 11. Metal wall 12.
It is transmitted to the object to be measured via the thermal expansion difference absorbing member 9 and the flow cell main body 5. When the temperature control sensor 10 determines that the temperature of the object to be measured matches the set temperature, the thermionic element 3 stops heating and controls the object by heating and cooling it with subtle temperature changes. Therefore, the object to be measured that is in contact with the temperature control sensor 10 is maintained at a constant temperature.

〔Effect of the invention〕

As mentioned above, since the flow cell is made of glass,
The curve of the hole, which follows the flow of the fluid being measured, makes it easy to perform 9-grade machining, and the inner surface of the flow path has few irregularities, so there is no air adhesion or residual contamination of the measured object. The accuracy of measurement data can be improved. It is now possible to measure harmful items that corrode metals, which were difficult to measure with conventional metal flow cells.

In addition, by filling the boundary between the metal wall and the flow cell with a material that absorbs the difference in thermal expansion, the difference in thermal expansion between metal and glass can be absorbed, and the glass 70-cell can be damaged under large thermal changes. There's nothing to do. Also, from the metal wall to the glass 70-
Thermal conductivity to the cell is improved, and the object to be measured can be maintained at the set temperature in a short time.

[Brief explanation of drawings]

FIG. 1 is a partially cutaway perspective view showing an embodiment of the constant temperature flow cell of the present invention, and FIG. 2 is an A of the constant temperature flow cell main body in FIG.
-A cross-sectional view, Figure 6 is B of the constant temperature full cell in Figure 1.
It is a front view seen from the direction. 1... Flow cell, 2... Photometric window, 3...
...Thermionic element, 4... Heat sink, 6... Suction pipe, 7... Drain pipe, 9... Member for absorbing thermal expansion difference, 12... Metal wall.

Claims (1)

[Claims] Heat is transferred by energizing a thermionic element trap, which is placed in contact with the flow cell into which the object to be measured is poured, either directly or through a material with good thermal conductivity, and heats or cools the object to be measured. In a constant-temperature flow cell that maintains an object to be measured at a constant temperature, a flow path through which the object to be measured flows is formed of glass, and a metal wall covering the outside of the glass flow path and the boundary between the flow path are A constant temperature flow cell characterized in that a member for absorbing the difference in thermal expansion between glass and the metal is embedded.