JPH0136895B2 - - Google Patents

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 early and shortening the processing time, thereby improving the accuracy of measurement data. In order to meet such demands, constant-temperature flow cells have been used, for example, in which a thermoelectronic element (for example, a Peltier element) is provided in a flow cell body into which an object to be measured is poured and photometry is performed.

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,
Advanced manufacturing techniques such as metal polishing and micromachining were 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 there is a drawback that air bubbles are attached due to processing scratches, burrs, etc., and the measurement accuracy is reduced.

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. Measurement was difficult due to metal ion precipitation.

〔the purpose〕

The present invention was made based on the above circumstances, and
There is less residual contamination of the object to be measured, and there is less air adhesion on the uneven inner surface, which improves the accuracy of measurement data, especially when the object to be measured is made of metal such as metal ions. The purpose of the present invention is to provide a constant temperature glass flow cell that can easily measure difficult measurement items or measurement items that are harmful to corrode metal flow cells, and is easy to manufacture.

〔overview〕

In order to achieve the above object, the present invention has a constant temperature flow cell that maintains the object to be measured at a constant temperature, in which a channel through which the object to be measured flows is formed of glass, and a metal wall covers the outside of the glass channel. and a member (having good thermal conductivity) for absorbing the difference in thermal expansion between the glass and the metal is inserted at the boundary between the glass and the metal.

〔Example〕

The constant temperature flow cell of the present invention will be explained below with reference to the drawings. FIG. 1 is a partially cutaway sectional view showing an embodiment of the constant temperature flow cell of the present invention. This is an example of what is used in a biochemical analyzer. In the figure, reference numeral 1 denotes a flow cell main body, and a photometric window 2 for passing analytical light is provided on the side of the flow cell 1, and thermionic elements 3, 3 (not shown) are provided on the other orthogonal surface. Attached via thermal compound. At this time, if the signs of the charges supplied to the thermionic elements 3 and 3 are equal, the contact surfaces of the thermionic elements 3 and 3 that are in contact with both sides of the flow cell body 1 are unified into one of the heating surface and the cooling surface. are doing. Then, heat is sent to the thermionic elements 3, 3, or thermionic elements 3,
A heat dissipating plate 4 for dissipating heat of 3 is attached to the flow cell body 1 via thermionic elements 3, 3. This heat sink 4 also includes a thermionic element 3 and a thermionic element 3 on the flow cell body 1
3 is fixed. 6 is a suction pipe for filling the flow cell with the object to be measured, and 7 is a suction pipe for filling the object to be measured into the flow cell.
This is a discharge pipe that discharges the object to be measured.

Next, referring to FIG. 2, the internal structure of the flow cell main body will be explained. Reference numeral 5 is a flow cell made of glass and has a suction pipe 6 for filling the object to be measured, a drain pipe 7 for discharging the object to be measured after measurement, and 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 solder), and the outer periphery is covered with a metal wall that also has good thermal conductivity (for example, silver, copper solder). )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. 3, inside the flow cell body 1, there is a flow cell 5 near the member 9 for absorbing thermal expansion difference.
A temperature control sensor 10 is buried near the center in the optical path length direction as close as possible to the object to be measured. Both sides of the thermionic elements 3, 3 are in 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 constant temperature flow cell configured in this manner is used by being attached to an appropriate automatic biochemical analyzer (not shown). Before the object to be measured is sucked into the flow cell 5 from the suction tube 6, the power is turned on. The Peltier device, also known as thermionic device 3, is known to have a Peltier effect, that is, a combination of two substances, e.g.
This method utilizes the effect that when a seed metal and a semiconductor are bonded and a current is passed therethrough, heat is generated or absorbed in addition to Joule heat at the bonding point. Since they are installed so that they are thermally similar (for example, on the heating side and 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, a control circuit (not shown) is operated to operate the thermionic element 3 in order to heat the object to be measured. The heat generated by thermionic element 3 is transferred to thermal compound 1
1. It is transmitted to the object to be measured via the metal wall 12, the member 9 for absorbing thermal expansion difference, and the flow cell 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 even with slight 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, it is easy to bend the hole along the flow of the fluid being measured, and the inner surface of the flow path has few irregularities to prevent air from adhering. Alternatively, there is no residual contamination of the object to be measured, and 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 thermal expansion differences, the difference in thermal expansion between metal and glass can be absorbed, and the glass flow cell will not be damaged even under large thermal changes. . In addition, the thermal conductivity from the metal wall to the glass flow 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, FIG. 2 is a sectional view taken along the line A-A of the constant temperature flow cell body shown in FIG. 1, and FIG. 3 is a constant temperature flow cell shown in FIG. 1. FIG. 3 is a front view of the flow cell as seen from direction B. FIG. 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] 1. Transfer of heat by energizing a thermionic element placed in contact with the flow cell into which the object to be measured is placed, either directly or through a substance with good thermal conductivity, to heat or cool the object to be measured, In a constant-temperature flow cell that maintains a measured object at a constant temperature, a flow path through which the measured object flows is formed of glass, and the glass is placed at the boundary between the flow path and a metal wall that covers the outside of this glass flow path. A constant temperature flow cell characterized in that a member for absorbing the difference in thermal expansion between the metal and the metal is embedded.