JPH064312Y2 - Flow cell leak sensor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a flow cell liquid leak sensor for use in a liquid chromatographic detector, a flow injection detector or the like, for detecting liquid leak from a flow cell.

[Prior Art] In a liquid chromatograph detector or the like, a photodetector is fixed to the inner side of a front end opening of a cylindrical light-shielding case with its light-receiving surface facing the opening side, and a flow cell is inserted from this opening into the light-shielding case. Many of them have a structure in which the blocks are detachably inserted.

While supplying a liquid sample to the flow cell of this flow cell block, there is a case where liquid leaks from the flow cell or a pipe joint connected to the flow cell. Electrodes were attached, and liquid leakage was detected based on changes in resistance or capacitance between the electrodes.

In order to take out the liquid leakage detection signal together with the output signal of the photodetector from the rear end surface or the side surface of the light shielding case through the wiring, conventionally, the pair of electrodes are fixed in the light shielding case. Also,
In order to prevent the electrode from colliding with the electrode when the flow cell block is inserted, the electrode is arranged in the light-shielding case slightly behind the flow cell.

[Problems to be solved by the invention] However, when liquid leakage is detected, the cleaning tool is inserted into the cylindrical light-shielding case after pulling out the flow cell block from the light-shielding case, and the inner part of the light-shielding case is inserted. It is necessary to clean the electrode fixed to the above and its surroundings. Especially, it is difficult to completely clean the electrode, and it is easy for an adhered substance to remain on the electrode. Even if there is no leakage, there is also a problem that it absorbs moisture in the air and causes a false alarm.

In view of the above problems, it is an object of the present invention to provide a flow cell liquid leak sensor that can easily clean electrodes.

[Means for Solving the Problems] In order to achieve this object, in the present invention, a cylindrical conductive light-shielding case having an opening at one end and the other end facing the one end being closed, and the light-shielding case. A photodetector fixed in the light-shielding case with the light-receiving surface facing the opening side at a position distant from the one end to the other end, and a flow cell fixed to one end of the cell support, A lid for closing the opening of the light-shielding case is fixed to the other end opposite to the one end, and a sample liquid introducing pipe and a sample liquid discharging pipe are penetrated through the lid, and the sample liquid introducing pipe and the sample liquid discharging One end of the tube is connected to the inlet and the outlet of the flow cell, and is detachably inserted from the opening of the light shielding case so that the flow cell faces the light receiving surface of the photodetector. With the flow cell block whose opening is closed In a device for detecting light from a sample solution flowing through the flow cell with the photodetector, and electrically detecting leakage of the sample solution from the flow cell, the cell support , A liquid leakage detection electrode fixed at a position between the lower part of the flow cell and a lower part of the flow cell and a part of the light shielding case facing the lower part of the flow cell, and a first switch piece attached to the flow cell block. And a first connection for electrically connecting the liquid leakage detection electrode and the first switch piece.
A lead wire and a second wire fixed to a predetermined position of the light shielding case
A switch piece; and a second lead wire, one end of which is connected to the second switch piece, at least a part of which is attached to the light shielding case, and the predetermined position is the lid that covers the opening of the light shielding case. Is a position where the second switch piece contacts the first switch piece and is electrically conducted in the closed state with the change in the resistance value or the electrostatic capacitance between the second lead wire and the light shielding case. The liquid leakage from the flow cell is detected based on the above.

Embodiments (1) One Embodiment One embodiment of the present invention will be described with reference to the drawings.

FIGS. 1 and 2 show a chemiluminescence detector which is one of the detectors of liquid chromatographs.

FIG. 1 is a vertical cross-sectional view of a main part of a flow cell block inserted state,
FIG. 2 is a transverse cross-sectional view of the relevant part.

Hereinafter, in the drawings, the left side is the front and the right side is the rear.

A photomultiplier tube 12 fitted with a ring-shaped holder 14 is housed in the cylindrical light-shielding case 10.
A plurality of mounting screws 16 screwed from the outside to the
Is pressed against the outer surface of the holder 14, and the photomultiplier tube 12 is set and fixed at a desired position by adjusting these mounting screws 16. Reference numeral 12a is a light receiving surface of the photomultiplier tube 12.

Although not shown, the rear end of the photomultiplier tube 12 is inserted into a socket, and the rear end of the light shielding case 10 is closed by a back cover.

The flow cell block 18 is configured to be removable from the light shielding case 10. That is, in the cell support rod 20,
The cell panel 36 is fixed to the front end by a mounting screw 38, the relay plate 32 is screwed to the central portion, and the plane mirror 22 is screwed to the rear end. The plane mirror 22 has a mirror surface on the side opposite to the cell support rod 20, and is brought into contact with the plane mirror 22 so that the light transmitting tube is spirally wound around the protrusion 20a of the cell support rod 20. The flow cell 24 is configured. The flow cell 24 includes a plane mirror 22 and a window plate 2.
It is sandwiched between 6 and 6. The window plate 26 is made of a light transmissive material, and the periphery thereof is held by a holding frame 28, and the holding frame 28 is fixed to the plane mirror 22 by a mounting screw 30. Both ends of the flow cell 24 are led out to the back side of the plane mirror 22 through the pores formed in the plane mirror 22, and are connected to a pipe 42 through a pipe joint 34 attached to the relay plate 32, and the pipe 42 is connected to the cell panel. Three
The light shielding pipe 40 of No. 6 is inserted.

The flat mirror 22 of the flow cell block 18 is formed with a through hole 22a penetrating the flat mirror 22, and one end of the lead wire 46 is inserted into the through hole 22a. The core wire of the lead wire 46 is required to cover the mirror surface side of the flat mirror 22. The liquid leak detection electrode 44 exposed by the length is projected. This liquid leak detection electrode 44
Is located below the flow cell 24 and is also the light shielding case 1
It is provided at a position having a predetermined distance from the inner surface of 0.

The other liquid leakage detection electrode is the light shielding case 10 itself. Therefore, the light shielding case 10 is made of a conductive material.

The lead wire 46 passes through the through hole 32 a of the relay plate 32,
The other end is soldered to the terminal plate 58 adhered to the inner surface of the cell panel 36.

As shown in FIG. 1, a connector 50 is attached to the front end of the light shielding case 10 so as to face the terminal plate 58. FIG. 3 is an enlarged cross-sectional view thereof, in which a sleeve 52 made of an insulating material is adhered to the inner surface of the light shielding case 10, and a sliding pin 54 is slidably mounted inside the light shielding case 10. It is energized. In the state where the flow cell block is inserted, the tip end surface of the sliding pin 54 is pushed by the terminal plate 58 and is retracted, so that the terminal plate 58 and the sliding pin 54 are electrically and reliably connected. While the flow cell block is being separated, the sliding pin 54 is separated from the terminal plate 58 as shown in FIG. Reference numeral 48 denotes a lead wire connected to the sliding pin 54, which is guided to the rear of the light shielding case 10 and is connected to an external liquid leakage sensor (not shown) together with the light shielding case 10.

Next, the operation of this embodiment configured as described above will be described.

The chemiluminescence from the sample sent into the flow cell 24 is received by the light receiving surface 12 a of the photomultiplier tube 12 and detected.

In the state where the flow cell block is inserted as shown in FIGS. 1 and 3, the liquid leakage detection electrode 44 has the lead wire 46 and the terminal board 5.
8. Connected to the lead wire 48 through the sliding pin 54.

When a liquid leaks from the flow cell 24 in this state, the leaked liquid falls and mainly collects between the liquid leak detection electrode 44 and the inner surface of the light shielding case 10 facing the liquid leak detection electrode 44, and the light shielding case 10 and the liquid leak detection electrode 44. The electric capacity or resistance between and changes, and liquid leakage is detected.

The operator disengages the flow cell block 18 from the light shielding case 10 by this detection. In this detached state, since the liquid leak detection electrode 44 is completely exposed to the outside, the liquid leak detection electrode 44 and the flat mirror 22 and the like around it can be easily and completely cleaned. Further, since there is no protruding liquid leakage detection electrode in the light shielding case 10, the liquid leakage portion in the light shielding case 10 can be easily cleaned.

After cleaning, the flow cell block 18 is again shielded from the light shielding case 10
When inserted inside, as shown in FIG. 3, the connector 50 automatically connects the liquid leakage detection electrode 44 and the lead wire 48, and the above-described detection operation is restarted.

Notches 22b and 32b are formed in the plane mirror 22 and the relay plate 32 as shown in FIG. 1, so that interference with the connector 50 can be avoided when the flow cell block 18 is attached or detached.

(2) Expansion The present invention includes various modifications.

For example, instead of using the connector 50 and the terminal plate 58, a male connector is attached to one of the ends of the lead wire 46 and the lead wire 48, and a female connector is attached to the other end of the lead wire 46 and the lead wire 48. You may make it contact and separate.

The present invention can also be applied to liquid chromatographic detectors such as UV detectors and detectors for flow injection.

[Advantages of the Invention] In the flow cell liquid leakage sensor according to the present invention, liquid leak detection is performed at a position of the cell support of the flow cell block between the lower portion of the flow cell and a portion of the light shielding case facing the lower portion of the flow cell. The flow cell block is fixed to the front end of the tubular conductive light-shielding case by fixing the flow cell to the front end of the cell support and the lid to close the opening of the light-shielding case at the rear end of the cell support. The opening of the light shielding case is closed by the lid in a state where the flow cell is detachably inserted from the opening and the flow cell faces the light receiving surface of the photodetector, and the liquid leakage detection electrode has the first lead wire in the flow cell block. The first switch piece that is conducted through is fixed, while the second switch piece connected to the second lead wire is fixed to the light shielding case and the light shielding case is opened. The second switch piece is brought into electrical contact with the first switch piece while the mouth is closed by the lid, and in this contact state, the resistance value or the electrostatic capacitance between the second lead wire and the light shielding case. Is configured to detect the liquid leakage from the flow cell based on the change of the flow cell, therefore, the flow cell block can be pulled out from the cylindrical conductive light shielding case without being bound by the lead wire connected to the electrode, This drawing has an excellent effect that the liquid leak detection electrode can be completely exposed to the outside, and the liquid leak detection electrode and its peripheral portion can be easily and sufficiently cleaned.

Further, since the liquid leakage detection electrode and its peripheral portion can be completely cleaned by this, it is possible to more completely prevent an erroneous alarm due to adhesion of a hygroscopic substance to the liquid leakage detection electrode and its peripheral portion. There is also an effect.

[Brief description of drawings]

FIG. 1 shows an embodiment of the present invention. FIG. 1 is a longitudinal sectional view of an essential part of a flow cell block inserted state, FIG. 2 is a lateral sectional view of the same, and FIG. 3 is an enlarged view of a connector portion of FIG. Sectional view, 4th
The drawing is an enlarged cross-sectional view similar to FIG. 3 in the middle of removal of the flow cell block. 10: Light-shielding case 12: Photomultiplier tube 18: Flow cell block 22: Plane mirror 24: Flow cell 44: Liquid leak detection electrode 46, 48: Lead wire 50: Connector 54: Sliding pin 58: Terminal plate

Claims (3)

[Scope of utility model registration request] 1. A cylindrical conductive light-shielding case (10) having an opening at one end and the other end facing the one end being closed, and a light receiving member at a position distant from the one end to the other end side of the light-shielding case. A photodetector (12) fixed in the light-shielding case with its surface facing the opening side, and a flow cell (24) at one end of the cell support (20, 22).
Is fixed, and a lid (36) for closing the opening of the light-shielding case is fixed to the other end of the cell support opposite to the one end, and a sample solution introducing tube and a sample solution extracting tube penetrate through the lid. Is
One end of the sample liquid introduction pipe and one end of the sample liquid discharge pipe are connected to the inlet and the outlet of the flow cell, respectively, and are detachably inserted from the opening of the light shielding case so that the flow cell faces the light receiving surface of the photodetector. The flow cell block (1) in which the lid closes the opening of the light shielding case.
8) and a flow cell liquid leak sensor for detecting the light from the sample liquid flowing through the flow cell with the photodetector, and electrically detecting the leakage of the sample liquid from the flow cell. A liquid leakage detection electrode (44) fixed to a position between the lower portion of the flow cell and a lower portion of the cell support and a portion of the light shielding case facing the lower portion of the flow cell, and attached to the flow cell block. A first switch piece (58), a first lead wire (46) for electrically connecting the liquid leakage detection electrode and the first switch piece, and a second lead wire fixed to a predetermined position of the light shielding case. A switch piece (50) and a second lead wire (48) having one end connected to the second switch piece and at least a part of which is attached to the light shielding case.
And the predetermined position is a position where the second switch piece is in electrical contact with the first switch piece in a state where the opening of the light shielding case is closed by the lid, A flow cell liquid leakage sensor, which detects liquid leakage from the flow cell based on a change in resistance value or capacitance between the second lead wire and the light shielding case. 2. The first switch piece (58) is fixed to an inner surface of the lid (36), and the second switch piece is fixed to a position of the inner surface of the light shielding case on the opening side. The flow cell liquid leak sensor according to claim 1, wherein 3. The first lead wire is a wire whose core wire is covered with an insulator, and the electrode (44) is a portion where the core wire is exposed by removing the coating at one end of the wire. The flow cell liquid leak sensor according to claim 1 or 2.