Reagent storage box for magnetic particle chemiluminescence detection

Abstract

The utility model relates to a reagent storage box for magnetic particle chemiluminescence detection, the reagent storage box comprises a box body, the box body comprises a reagent tube rack groove used for clamping a reagent tube rack; the at least two auxiliary grooves are used for placing quality control product tubes and / or calibration product tubes; and the liquid level sensing elements are mounted in the reagent tube rack grooves and are used for being matched with the reagent tubes held by the reagent tube rack one by one so as to obtain liquid level information in the corresponding reagent tubes. The reagent storage box disclosed by the utility model can be used for placing a group of reagents for magnetic particle chemiluminescence detection and matched calibrators and quality control products, and can also be used for acquiring liquid level information in corresponding reagent tubes to remind an operator to supplement the corresponding reagents in time, so that reagent needles are prevented from touching the walls of the reagent tubes during subsequent detection.

Description

Technical Field

[0001] The utility model relates to the field of magnetic particle chemiluminescence detection, in particular to a reagent storage box for magnetic particle chemiluminescence detection. Background Art

[0002] Magnetic particle chemiluminescence immunoassay is an emerging analytical method that combines magnetic separation technology, chemiluminescence technology, and immunoassay technology. It has the advantages of good safety, automated operation, test accuracy, and test speed.

[0003] Magnetic particle chemiluminescent reagents are generally composed of magnetic particle reagents, detection reagents, calibrators, quality control products and reagent racks. Some magnetic particle chemiluminescent reagents also include capture reagents, where a magnetic particle reagent tube, a detection reagent tube and a capture reagent tube constitute a group of reagents. The three reagent tubes are installed together on a reagent rack. When testing, the reagent rack is placed on the magnetic particle chemiluminescence detector for detection. In addition to placing the test tube rack during the experiment, calibrators and quality control products also need to be installed. At present, test tube racks, calibrators or quality control products are placed separately, and multiple boxes need to be transported at low temperature from the reagent preparation area to the detector, which is very cumbersome.

[0004] Since magnetic particle reagents tend to precipitate and aggregate after being left for a long time, a mounting portion is provided at the bottom of the magnetic particle reagent tube, which extends from the bottom of the reagent rack to fit the rotating drive of the magnetic particle chemiluminescence detector. The magnetic particle reagent tube rotates around its own axis during the detection process to prevent the magnetic particles from settling. Due to the design requirements of the bottom of the magnetic particle reagent tube, the bottom wall of the reagent rack is uneven, resulting in an unstable center of gravity, and it is easy to fall over when placed on the laboratory table, causing reagent loss and contamination.

[0005] In addition, most of the magnetic particle chemiluminescence reagents on the market are in large packages of 48T-96T. During the detection process, because the samples sent for inspection are not concentrated, large packages of reagents are not used continuously during the detection, and the operators are not clear about the remaining reagents in the reagent tube. The magnetic particle chemiluminescence detector requires the reagent needle to move downward to absorb the reagent from the reagent tube during the detection. The reagent needle will drop as the reagent liquid level drops. The uncertainty of the remaining reagent in the reagent tube can easily cause the reagent needle to touch the bottom wall of the reagent tube and be damaged. Utility Model Content

[0006] Based on the above-mentioned defects in the prior art, the purpose of the utility model is to provide a reagent storage box for magnetic microparticle chemiluminescence detection, which can hold a group of magnetic microparticle chemiluminescence detection reagents and corresponding calibration products and quality control products, and can also obtain the liquid level information in the corresponding reagent tube to remind the operator to replenish the corresponding reagent in time to avoid the reagent needle touching the wall of the reagent tube during subsequent detection.

[0007] To this end, the utility model provides the following technical solutions.

[0008] The utility model provides a reagent storage box for magnetic particle chemiluminescence detection, the reagent storage box comprises a box body, and the box body comprises:

[0009] A reagent tube rack slot, which is used to mount the reagent tube rack;

[0010] At least two auxiliary slots, wherein the at least two auxiliary slots are used to place quality control tubes and / or calibration tubes;

[0011] The liquid level sensor element is installed in the reagent tube rack slot and is used to match one by one with the reagent tubes held by the reagent tube rack to obtain the liquid level information in the corresponding reagent tubes.

[0012] Preferably, the box body is provided with a liquid inlet, a heat preservation liquid cavity and a liquid outlet which are connected in sequence, and the heat preservation liquid cavity surrounds the reagent tube rack slot and the at least two auxiliary slots.

[0013] Preferably, a card slot and a card protrusion are respectively provided on both sides of the box body, and two adjacent box bodies are card-connected through the card slot and the card protrusion to form a multi-unit combination.

[0014] Preferably, the number of the auxiliary slots is four, for placing two of the quality control tubes and two of the calibration tubes.

[0015] Preferably, the reagent storage box comprises a reagent tube, a metal contact is provided at the bottom of the reagent tube, and the metal contact matches the liquid level sensing element one by one to obtain the liquid level information.

[0016] Preferably, the reagent storage box comprises a reagent tube rack, the reagent tubes comprise magnetic particle reagent tubes and detection reagent tubes, and the reagent tube rack comprises a first tube slot for accommodating the magnetic particle reagent tubes and a second tube slot for accommodating the detection reagent tubes;

[0017] A first through hole is provided at the bottom of the first tube groove, and a mounting portion is provided on the bottom wall of the magnetic particle reagent tube, and the mounting portion passes through the first through hole and is used to connect with the rotating driving member of the detector; the mounting portion is an annular structure to form a first mounting groove, and a first metal contact is installed in the first mounting groove;

[0018] A second through hole is provided at the bottom of the second tube groove, and a second metal contact is installed at the bottom of the detection reagent tube, and the second metal contact is inserted into the second through hole.

[0019] Preferably, the reagent tube includes a capture reagent tube, and the reagent tube rack includes a third tube groove for accommodating the capture reagent tube; a third through hole is provided at the bottom of the third tube groove, and a third metal contact is installed at the bottom of the capture reagent tube, and the third metal contact is inserted into the third through hole.

[0020] Preferably, the cross-section of the outer contour of the reagent tube rack is trapezoidal, the cross-section of the reagent tube rack groove is trapezoidal, and the reagent tube rack and the reagent tube rack groove are matched in shape to achieve card installation.

[0021] Preferably, the bottom wall of the reagent tube rack includes a first bottom surface and a second bottom surface that are staggered up and down, the first through hole is provided on the first bottom surface, the second through hole and the third through hole are provided on the second bottom surface, and the bottom wall of the reagent tube rack groove is provided with a first abutting wall and a second abutting wall that are staggered up and down;

[0022] When the reagent tube rack is clamped in the reagent tube rack slot, the first abutting wall abuts against the first bottom surface, and the second abutting wall abuts against the second bottom surface.

[0023] Preferably, the first abutting wall is provided with a second installation groove, in which one of the liquid level sensing elements is installed; and the second abutting wall is embedded with two of the liquid level sensing elements;

[0024] When the reagent tube rack is mounted in the reagent tube rack slot, one of the liquid level sensing elements is inserted into the mounting portion to contact the first metal contact, and the other two liquid level sensing elements are respectively in contact with the second metal contact and the third metal contact.

[0025] The utility model has the following technical effects:

[0026] The utility model provides a reagent storage box for magnetic particle chemiluminescence detection, which is provided with a reagent tube rack slot and an auxiliary slot, and can place a group of magnetic particle chemiluminescence detection reagents and matching calibration products and quality control products, and one detection project can match one reagent tube rack slot, so as to avoid mistakenly taking reagents of different projects due to improper operation. In addition, a liquid level sensor element is provided in the reagent tube rack slot, so as to obtain the liquid level information in the corresponding reagent tube, and when the liquid level is lower than the warning value, it can remind the operator to replenish the corresponding reagent in time, so as to avoid the reagent needle from touching the bottom wall of the reagent tube due to the drop of the reagent liquid level, reduce the risk of damage to the reagent needle, and avoid economic losses caused by damage to the reagent needle. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 The three-dimensional structure diagram of the box body of the utility model Figure 1 ;

[0028] Figure 2 The three-dimensional structure diagram of the box body of the utility model Figure 2 ;

[0029] Figure 3 It is a structural cross-sectional view of the box body of the utility model;

[0030] Figure 4 It is a three-dimensional structural schematic diagram of the triple box body of the utility model;

[0031] Figure 5 This is a structural explosion diagram of the magnetic particle reagent tube of the utility model;

[0032] Figure 6 It is a schematic diagram of the three-dimensional structure of the magnetic particle reagent tube of the utility model;

[0033] Figure 7 This is a schematic diagram of the assembly structure of the reagent tube rack and reagent tubes of the utility model.

[0034] Description of Reference Numerals

[0035] 1. Box body; 11. Reagent tube rack slot; 111. First abutting wall; 1111. Second mounting slot; 112. Second abutting wall; 12. Auxiliary slot; 13. Liquid level sensor element; 14. Liquid inlet; 15. Insulating liquid cavity; 16. Liquid outlet; 17. Card slot; 18. Card protrusion;

[0036] 2. Reagent tube rack; 21. First bottom surface; 22. Second bottom surface;

[0037] 31. Magnetic particle reagent tube; 311. Mounting portion; 3111. First mounting groove; 3112. Protruding structure; 312. First metal contact;

[0038] 32. a detection reagent tube; 321. a second metal contact;

[0039] 33. Capture reagent tube; 331. Third metal contact. DETAILED DESCRIPTION

[0040] In order to make the technical solution and beneficial effects of the utility model more obvious and easy to understand, the following is a detailed description by listing specific embodiments. Unless otherwise defined, the technical and scientific terms used in this article have the same meaning as those in the technical field to which this application belongs.

[0041] In the description of the present invention, unless otherwise explicitly defined, terms such as “center”, “longitudinal”, “lateral”, “length”, “width”, “thickness”, “height”, “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “clockwise”, “counterclockwise”, etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings and are only for the convenience of simplified description of the present invention, and do not indicate that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and should not be understood as a limitation on the present invention.

[0042] In the present invention, the terms "first" and "second" are used only for the purpose of clear description and cannot be understood as the relative importance of the indicated features or the number of the indicated technical features. Therefore, the features defined as "first" and "second" can explicitly include at least one of the features. In the description of the present invention, "multiple" means at least two; "several" means at least one, unless otherwise clearly defined.

[0043] In the present invention, unless otherwise clearly defined, the terms "install", "connect", "connect", "fix", "set", etc. should be understood in a broad sense. For example, "connection" can be a fixed connection, a detachable connection, or an integral molding; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0044] In the present utility model, unless otherwise clearly defined, a first feature being “on”, “above”, “above”, “below”, “below”, “below” or “below” a second feature may mean that the first feature is in direct contact with the second feature, or the first feature and the second feature are in indirect contact through an intermediate medium. Moreover, a first feature being “on”, “above” or “above” a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the horizontal height of the first feature is higher than the horizontal height of the second feature. A first feature being “below”, “below” or “below” a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the horizontal height of the first feature is lower than the horizontal height of the second feature.

[0045] The "upper" and "lower" mentioned in this utility model are all Figure 1 and Figure 7 The markings in shall prevail.

[0046] According to the following Figures 1 to 7 The reagent storage box of the utility model is described in detail.

[0047] In this embodiment, if Figure 1 As shown, the reagent storage box includes a box body 1, and the box body 1 includes a reagent tube rack slot 11, an auxiliary slot 12 and a liquid level sensor element 13. The number of the reagent tube rack slot 11 is one, which is used to clamp a reagent tube rack 2, and the reagent tube rack 2 is used to place a group of large-packaged reagent tubes. The reagent in each reagent tube can be used for multiple detections. The number of the auxiliary slots 12 is four, wherein two auxiliary slots 12 are used to place quality control product tubes, and the other two auxiliary slots 12 are used to place calibration product tubes. Of course, the number of the auxiliary slots 12 is not limited to four, and can also be two, three or even more. The liquid level sensor element 13 is installed in the reagent tube rack slot 11, and the number of the liquid level sensor element 13 is consistent with the number of reagent tubes placed in the reagent tube rack 2. The liquid level sensor element 13 is used to match the reagent tubes one by one to obtain the liquid level information in the corresponding reagent tube.

[0048] By adopting the above technical solution, setting the reagent tube rack slot 11 and the auxiliary slot 12, the box body 1 can place a group of magnetic microparticle chemiluminescence detection reagents and matching calibration products and quality control products, and one detection project can match one reagent tube rack slot 11 to avoid mistakenly taking reagents of different projects due to improper operation. In addition, a liquid level sensor element 13 is set in the reagent tube rack slot 11 to obtain the liquid level information in the corresponding reagent tube. When the liquid level is lower than the warning value, the operator can be reminded to replenish the corresponding reagent in time, so as to avoid the reagent needle from touching the bottom wall of the reagent tube due to the drop of the reagent liquid level, reduce the risk of damage to the reagent needle, and avoid economic losses caused by damage to the reagent needle.

[0049] In one embodiment, if Figures 1 to 3 As shown, the box body 1 is provided with a liquid inlet 14, a heat preservation liquid cavity 15 and a liquid outlet 16 which are connected in sequence. The heat preservation liquid cavity 15 surrounds the reagent tube rack slot 11 and the auxiliary slot 12. According to the corresponding temperature requirement of the detection, the heat preservation liquid of the corresponding temperature (such as 0°C, 4°C, 25°C or 37°C) is introduced into the heat preservation liquid cavity 15 from the liquid inlet 14 to provide the best storage temperature for the magnetic particle chemical waste reagent, so as to avoid the degradation of the reagent performance due to the large temperature change. Among them, the heat preservation liquid can be continuously introduced from the liquid inlet 14, and then discharged from the liquid outlet 16, and the heat preservation is carried out by the flowing heat preservation liquid. Of course, the heat preservation liquid can also be introduced from the liquid inlet 14, and then discharged after a period of time and new heat preservation liquid is introduced again.

[0050] In one embodiment, if Figure 1 , Figure 2 and Figure 4As shown, a card slot 17 and a card connection protrusion 18 are respectively provided on both sides of the box body 1. Two adjacent box bodies 1 are card-connected by the card slot 17 and the card connection protrusion 18 to form a multi-unit combination. In this way, it can be applied to multiple joint inspection items. In addition, the line structure of the outer contour of the box body 1 can constitute the position distinction of different box bodies 1, which can effectively classify different items, reduce the probability of mixing reagents, calibrators or quality control reagents when multiple items are tested simultaneously, and improve the convenience of reagent use.

[0051] Furthermore, the number of the clamping slots 17 and the number of the clamping protrusions 18 are both two, so as to improve the stability of the clamping.

[0052] In one embodiment, the reagent storage box includes a reagent tube, and a metal contact is provided at the bottom of the reagent tube. The metal contact matches the liquid level sensor element 13 one by one to obtain liquid level information.

[0053] Furthermore, if Figures 5 to 7 As shown, the reagent storage box includes a reagent tube rack 2, the reagent tubes include a magnetic particle reagent tube 31 and a detection reagent tube 32, and the reagent tube rack 2 includes a first tube groove (not shown in the figure) for accommodating the magnetic particle reagent tube 31 and a second tube groove (not shown in the figure) for accommodating the detection reagent tube 32. A first through hole is provided at the bottom of the first tube groove, and a mounting portion 311 is provided on the bottom wall of the magnetic particle reagent tube 31. The mounting portion 311 passes through and partially extends out of the first through hole. When the reagent tube rack 2 is placed in a detector for detection, the mounting portion 311 of the magnetic particle reagent tube 31 is connected to the rotating drive member of the detector. In this way, during detection, the transmission drive member can drive the magnetic particle reagent tube 31 to rotate around its own axis to prevent the magnetic particles from settling and agglomerating. The mounting portion 311 is annular in structure to form a first mounting groove 3111, and a first metal contact 312 is mounted in the first mounting groove 3111. In this solution, the first metal contact 312 is directly mounted in the mounting portion 311, which makes little structural change to the magnetic particle reagent tube 31 and can reduce processing costs. A second through hole is provided at the bottom of the second tube groove, and a second metal contact 321 is mounted at the bottom of the detection reagent tube 32, and the second metal contact 321 is inserted into the second through hole.

[0054] Furthermore, if Figure 7 As shown, the reagent tube also includes a capture reagent tube 33, and the reagent tube rack 2 includes a third tube groove for accommodating the capture reagent tube 33. A third through hole is provided at the bottom of the third tube groove, and a third metal contact 331 is installed at the bottom of the capture reagent tube 33, and the third metal contact 331 is inserted into the third through hole.

[0055] Furthermore, if Figure 7 As shown, the cross section of the outer contour of the reagent tube rack 2 is a trapezoid. Figure 1As shown, the cross section of the reagent tube rack slot 11 is trapezoidal, and the reagent tube rack 2 and the reagent tube rack slot 11 are matched in shape to achieve card installation. The reagent tube rack 2 and the reagent tube rack slot 11 can be tightly embedded, thereby improving the stability of the placement of the reagent tube rack 2.

[0056] Furthermore, if Figure 7 As shown, since the bottom of the magnetic particle reagent tube 31 is provided with a mounting portion 311, and the mounting portion 311 needs to extend from the bottom of the reagent tube rack 2 to be connected to the rotating drive member of the detector, the bottom surface of the reagent tube rack 2 is uneven. Specifically, as shown in FIG. Figure 7 As shown, the bottom wall of the reagent tube rack 2 includes a first bottom surface 21 and a second bottom surface 22 that are staggered up and down, the first through hole is provided on the first bottom surface 21, and the second through hole and the third through hole are provided on the second bottom surface 22. Figure 1 As shown, the bottom wall of the reagent tube rack slot 11 is provided with a first abutting wall 111 and a second abutting wall 112 which are staggered up and down. When the reagent tube rack 2 is clamped in the reagent tube rack slot 11, the first abutting wall 111 abuts against the first bottom surface 21, and the second abutting wall 112 abuts against the second bottom surface 22, which is conducive to stably supporting the reagent tube rack 2.

[0057] Furthermore, if Figure 1 As shown, the first abutting wall 111 is provided with a second installation groove 1111, a liquid level sensor element 13 is installed in the second installation groove 1111, and two liquid level sensor elements 13 are embedded in the second abutting wall 112. Figure 1 and Figure 7 As shown, the upper surface of the liquid level sensor element 13 in the second mounting groove 1111 is lower than the first abutting wall 111. When the reagent tube rack 2 is clamped in the reagent tube rack groove 11, the mounting portion 311 is inserted into the second mounting groove 1111 and surrounds the liquid level sensor element 13, that is, the liquid level sensor element 13 is inserted into the mounting portion 311 and contacts the first metal contact 312 to obtain the liquid level information in the magnetic particle reagent tube 31. The upper surfaces of the two liquid level sensor elements 13 arranged on the second abutting wall 112 are flush with the second abutting wall 112 or slightly protrude from the second abutting wall 112. The two liquid level sensor elements 13 are in contact with the second metal contact 321 and the third metal contact 331 respectively to obtain the liquid level information in the detection reagent tube 32 and the capture reagent tube 33 respectively.

[0058] Furthermore, if Figure 6 and Figure 7 As shown, the outer wall of the mounting portion 311 is provided with symmetrically arranged protrusion structures 3112 , which are used to engage with the rotating driving member of the detector so that the rotating driving member can transmit the rotational force to the mounting portion 311 .

[0059] It should be understood that the above embodiments are exemplary and are not intended to include all possible implementations included in the claims. Various modifications and changes may be made on the basis of the above embodiments without departing from the scope of the present disclosure. Similarly, the various technical features of the above embodiments may be arbitrarily combined to form other embodiments of the utility model that may not be explicitly described. Therefore, the above embodiments only express several implementations of the utility model and do not limit the scope of protection of the utility model patent.

Claims

1. A reagent storage box for magnetic microparticle chemiluminescence detection, characterized in that: The reagent storage box comprises a box body (1), and the box body (1) comprises: A reagent tube rack slot (11) for mounting the reagent tube rack (2); At least two auxiliary slots (12), wherein the at least two auxiliary slots (12) are used to place quality control tubes and / or calibration tubes; A liquid level sensor element (13) is installed in the reagent tube rack slot (11) and is used to match one by one with the reagent tubes held by the reagent tube rack (2) to obtain liquid level information in the corresponding reagent tubes.

2. The magnetic microparticle chemiluminescence detection reagent storage box according to claim 1, characterized in that: The box body (1) is provided with a liquid inlet (14), a heat preservation liquid chamber (15) and a liquid outlet (16) which are connected in sequence, and the heat preservation liquid chamber (15) surrounds the reagent tube rack slot (11) and the at least two auxiliary slots (12).

3. The magnetic microparticle chemiluminescence detection reagent storage box according to claim 1, characterized in that: A clamping groove (17) and a clamping protrusion (18) are respectively provided on both sides of the box body (1), and two adjacent box bodies (1) are clamped together via the clamping groove (17) and the clamping protrusion (18) to form a multi-unit combination.

4. The magnetic microparticle chemiluminescence detection reagent storage box according to claim 1, characterized in that: The number of the auxiliary slots (12) is four, which are used to place two quality control tubes and two calibration tubes.

5. The magnetic microparticle chemiluminescence detection reagent storage box according to any one of claims 1 to 4, characterized in that: The reagent storage box comprises a reagent tube, the bottom of which is provided with a metal contact, and the metal contact matches the liquid level sensing element (13) one by one to obtain the liquid level information.

6. The magnetic microparticle chemiluminescence detection reagent storage box according to claim 5, characterized in that: The reagent storage box comprises a reagent tube rack (2), the reagent tubes comprise magnetic particle reagent tubes (31) and detection reagent tubes (32), and the reagent tube rack (2) comprises a first tube slot for accommodating the magnetic particle reagent tubes (31) and a second tube slot for accommodating the detection reagent tubes (32); A first through hole is provided at the bottom of the first tube groove, and a mounting portion (311) is provided on the bottom wall of the magnetic particle reagent tube (31), and the mounting portion (311) passes through the first through hole and is used to connect with a rotating driving member of the detector; the mounting portion (311) is an annular structure to form a first mounting groove (3111), and a first metal contact (312) is installed in the first mounting groove (3111); A second through hole is provided at the bottom of the second tube groove, and a second metal contact (321) is installed at the bottom of the detection reagent tube (32), and the second metal contact (321) is inserted into the second through hole.

7. The magnetic microparticle chemiluminescence detection reagent storage box according to claim 6, characterized in that: The reagent tube comprises a capture reagent tube (33), and the reagent tube rack (2) comprises a third tube groove for accommodating the capture reagent tube (33); a third through hole is provided at the bottom of the third tube groove, and a third metal contact (331) is installed at the bottom of the capture reagent tube (33), and the third metal contact (331) is inserted into the third through hole.

8. The magnetic microparticle chemiluminescence detection reagent storage box according to claim 6, characterized in that: The cross section of the outer contour of the reagent tube rack (2) is a trapezoid, the cross section of the reagent tube rack slot (11) is a trapezoid, and the reagent tube rack (2) and the reagent tube rack slot (11) are matched in shape to achieve clamping.

9. The magnetic microparticle chemiluminescence detection reagent storage box according to claim 7, characterized in that: The bottom wall of the reagent tube rack (2) comprises a first bottom surface (21) and a second bottom surface (22) which are staggered up and down, the first through hole is arranged on the first bottom surface (21), the second through hole and the third through hole are arranged on the second bottom surface (22), and the bottom wall of the reagent tube rack groove (11) is provided with a first abutting wall (111) and a second abutting wall (112) which are staggered up and down; When the reagent tube rack (2) is clamped in the reagent tube rack slot (11), the first abutting wall (111) abuts against the first bottom surface (21), and the second abutting wall (112) abuts against the second bottom surface (22).

10. The magnetic microparticle chemiluminescence detection reagent storage box according to claim 9, characterized in that: The first abutting wall (111) is provided with a second installation groove (1111), and one of the liquid level sensing elements (13) is installed in the second installation groove (1111); and two of the liquid level sensing elements (13) are embedded in the second abutting wall (112); When the reagent tube rack (2) is mounted in the reagent tube rack slot (11), one of the liquid level sensing elements (13) is inserted into the mounting portion (311) to contact the first metal contact (312), and the other two of the liquid level sensing elements (13) are in contact with the second metal contact (321) and the third metal contact (331), respectively.

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