JPH10132640A - Liquid level detection device and method therefor, and automatic analysis device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately detect the liquid level of a liquid to be inspected generating bubbles and films easily. SOLUTION: With electrodes 61 and 3 for detecting the liquid level of a liquid to be inspected 2 in a container 1, a conductive member is provided at the tip of the electrode 61. When a signal that is transmitted from the electrodes 61 and 3 maintains a specified level continuously at least for a specific amount of time, the above liquid level is detected, thus preventing the detection of the bubbles and films of the inspection liquid 2 in the container 1 from being mistaken as the above liquid level by mistake and hence detecting the above liquid level accurately.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention accurately detects the level of a test solution such as blood, which is liable to generate bubbles and membranes when housed in a container such as a vacuum blood collection tube. The present invention relates to a liquid level detecting device and a liquid level detecting method capable of detecting a liquid level, and an automatic analyzer using the liquid level detecting device and the liquid level detecting method.

[0002]

2. Description of the Related Art For example, there is a biochemical automatic analyzer having a structure as shown in FIG. 8, for example, which automatically performs component analysis and component amount analysis of a test solution such as blood and urine. In each of the drawings, components that perform the same or similar functions are denoted by the same reference numerals. The outline of the operation of the biochemical automatic analyzer 20 is as follows. The test solution 2 accommodated in the container 1 is sucked, and the sucked test solution 2 is injected into the reaction tank 6 containing the buffer solution 7. The analysis of the test solution 2 is performed based on the reaction between the test solution 2 and the buffer solution 7 in the tank 6, and the measurement result is output. The structure of the biochemical automatic analyzer 20 will be outlined below with reference to FIG. The test solution 2 is a liquid such as blood or urine, and particularly a liquid in which bubbles and a film are likely to be generated when the test solution 2 is stored in the container 1. As an example of the container 1,
For example, there is a vacuum blood collection tube. The nozzle 3 for sucking the test solution 2 contained in such a container 1 from one end is
It is a stainless steel tube having a diameter of about 1 mm and a length of about 7 cm, which is also an electrode for detecting the liquid level of the test solution 2 together with the liquid level detecting electrode 10 as described later, and the other end is a tube 5. Is connected to the suction / discharge device 4 via the. The nozzle 3 is juxtaposed with the arm 9a so as to be inserted into the container 1 in a non-contact state with the rod-shaped liquid level detection electrode 10 made of metal. The arm 9a has the nozzle 3
The arm driving device 9 moves up and down in the vertical direction I so that the liquid level detection electrode 10 and the liquid level detection electrode 10 can advance and retreat into the container 1 at the same time. The nozzle 3 and the liquid level detection electrode 10 are both made of a metal material as described above, and when both of them come into contact with the test solution 2, the control device 8 controls the electrical conduction through the test solution 2.
Is applied, and the presence or absence of the electrical conduction is determined. The control device 8 is electrically connected to the suction / discharge device 4, the arm driving device 9, and the reaction tank 6, and controls the operation of each of these components. In addition, the said nozzle 3,
The liquid level detecting device 22 is composed of the liquid level detecting electrode 10 and the control device 8. Reference numeral 12 denotes an output device for displaying and printing information sent by the control device 8, and 13 denotes a valve connected to the suction / discharge device 4 and operation-controlled by the control device 8.

The operation of the automatic biochemical analyzer 20 having such a configuration will be described with reference to FIG. In step (indicated by “S” in FIG. 1), the nozzle 3 and the liquid level detection electrode 10 are sampled so that the nozzle 3 and the liquid level detection electrode 10 can be inserted into the container 1 for sampling the test liquid 2. It is moved to the position by the arm driving device 9. In step 2, the arm driving device 9 starts lowering the arm 9a. Therefore, the nozzle 3 and the liquid level detection electrode 10 start descending into the container 1. In step 3, the controller 8 causes the nozzle 3 and the liquid level detection electrode 10
Are both in contact with the test solution 2 in the container 1, that is, whether or not there is electrical continuity between the nozzle 3 and the liquid level detection electrode 10 via the test solution 2, and the electrical continuity is obtained. Until then, the lowering of the nozzle 3 and the liquid level detecting electrode 10 is continued within a predetermined lowering range. Then, when the control device 8 determines that the electrical conduction has been obtained in step 3, the arm drive device 9 stops the lowering of the arm 9 a under the control of the control device 8 in step 4. Therefore, the lowering operation of the nozzle 3 and the liquid level detection electrode 10 stops. At this point, the tip of the nozzle 3 exists in the test solution 2 because the electrical conduction through the test solution 2 is obtained as described above. still,
In step 3, when the lowering of the arm 9a exceeds the lowering range without obtaining the electrical continuity, the controller 8 determines that the test solution 2 does not exist in the container 1, and The descent of 9a is stopped. In step 5,
The suction / discharge device 4 performs a suction operation under the control of the control device 8, and the test solution 2 is supplied to the nozzle 3 via the tube 5 and the nozzle 3.
It is sucked inside or beyond the nozzle 3 to a part of the tube 5.

In step 6, after the suction, the control device 8
The arm driving device 9 raises the arm 9a to dispose the nozzle 3 and the liquid level detection electrode 10 outside the container 1.
Next, the nozzle 3 and the liquid level detection electrode 10 are
The arm driving device 9 moves the arm 9a in the horizontal direction II perpendicular to the vertical direction under the control of the control device 8 until the position where the arm 9a can be inserted. In step 7, the control device 8
After the arm driving device 9 lowers the arm 9a by the control of the above, the nozzle 3 and the liquid level detection electrode 10 are immersed in the buffer solution 7 of the reaction tank 6, and then the test solution 2 stored in the nozzle 3
Is discharged into the buffer solution 7 of the reaction tank 6 by the suction / discharge device 4 under the control of the control device 8. In step 8, the discharged test solution 2 and the buffer solution 7 are stirred, and in step 9, the test solution 2 is analyzed by the measuring device 11 communicating with the reaction tank 6, and the calculated measurement result is measured. It is sent from the device 11 to the control device 8. Then, the analysis result is sent from the control device 8 to the output device 12, where printing or the like is performed. Thereafter, by repeating steps 1 to 9, the analysis of the plurality of test solutions 2 can be automatically and continuously performed.

[0005]

However, the above-described automatic biochemical analyzer 20 has the following problems. That is, since the nozzle 3 sucks the test solution 2 as described above, the tip of the nozzle 3 needs to be present in the test solution 2. On the other hand, the test solution 2 is a liquid such as blood or urine which has a viscosity in which bubbles 25 and a film 26 of the test solution 2 tend to be generated when the test solution 2 is stored in the container 1 as shown in FIG. Further, as described above, the nozzle 3 and the liquid level detection electrode 10 are made of metal, and can be electrically connected to the test liquid 2 on the entire surface.
Therefore, when the nozzle 3 and the liquid level detection electrode 10 are simultaneously in contact with the bubble 25 or the film 26, the bubble 25 or the film 2
The above-mentioned electrical continuity is established through the nozzle 6, and a change in voltage is sent from the nozzle 3 and the liquid level detection electrode 10 to the control device 8. As described above, although the nozzle 3 does not actually contact the liquid surface 2 a of the test solution 2, the above-described voltage change occurs when the nozzle 3 comes into contact with the bubble 25 or the film 26. Therefore, a state occurs in which the test liquid 2 cannot be sucked by the nozzle 3. Therefore, in order to detect that the nozzle 3 has truly reached the liquid level 2a, the control device 8 needs to set, for example, a threshold value of the voltage level, but the setting is very difficult. Therefore, erroneous recognition of the liquid level 2a still occurs.

As a method of avoiding such erroneous recognition, a method of detecting the liquid level 2a of the test solution 2 as described above is used.
A method is conceivable in which the nozzle 3 is always lowered into the container 1 at a uniform lowering distance. However, this method has the following problems. That is, for example, when the container 1 is a vacuum blood collection tube, the blood collection amount, that is, the amount of the test solution 2 contained in the container 1 is not constant depending on the blood collector, the number of analysis items of the blood, and the like. Therefore, it is not preferable that the descending distance is uniformly determined, because a case where the test liquid 2 is contained in the container 1 and the liquid cannot be suctioned by the nozzles. Further, in the automatic biochemical analyzer 20 as described above, the nozzle 3 is immersed in the buffer solution 7 in the reaction tank 6 and then the test solution 2 in the nozzle 3 is discharged into the buffer solution 7 as described above. Is done. Further, the amount of the test solution 2 used for the analysis in the reaction tank 6 is very small, and the quantitative relationship between the buffer solution 7 and the test solution 2 in the reaction tank 6 in order to secure the analysis accuracy. Must be kept constant. Therefore, when the nozzle 3 is lowered into the container 1 according to the uniform descending distance, the amount of the test solution 2 adhering to the tube wall on the outer periphery of the nozzle 3 differs depending on the amount of the test solution 2 contained in the container 1. However, the quantitative relationship between the buffer solution 7 and the test solution 2 cannot be kept constant, and the analysis accuracy deteriorates.

Therefore, the biochemical automatic analyzer 20 described above
In order to solve the above-described problems and ensure the analysis accuracy of the test solution 2, it is necessary to accurately determine that the tip of the nozzle 3 has contacted the liquid surface 2a of the test solution 2 instead of the bubble 25 or the membrane 26. Need to detect. Therefore, the present invention provides a liquid level detection device and a liquid level detection method capable of accurately detecting the liquid level of a test solution in which bubbles and a film are likely to be generated when stored in a container, and the liquid level detection method. It is an object to provide an automatic analyzer using the device and the method.

[0008]

A liquid level detecting device according to a first aspect of the present invention is a liquid level detecting device for detecting a liquid level of a liquid collected in a container, wherein the liquid level detecting device contacts the liquid in the container. First and second electrodes, at least one of which has a first and a second electrode having a conductive portion at the tip of a component of the electrode, the liquid and the conductive member, The signal output from the first and second electrodes is supplied by conducting, and the supplied signal is such that the first and second electrodes are applied to the liquid instead of the bubbles or films formed in the liquid. When the liquid detection signal is supplied when contacted and the liquid detection signal is continuously maintained for a predetermined time or more,
A controller for determining that the first and second electrodes have contacted the liquid surface.

Further, the liquid level detecting method according to the second aspect of the present invention comprises:
A liquid level detection device for detecting the liquid level of the liquid collected in the container, the first and second electrodes contacting the liquid in the container, at least one of them,
In a liquid level detection method performed in a liquid level detection device including first and second electrodes having a conductive portion at the tip of a component of the electrode, when the liquid comes into contact with the conductive member, A first having a conductive portion at the tip
And a liquid detection signal that is transmitted from the second electrode when the liquid comes into contact with the liquid instead of a bubble or film formed in the liquid, and the liquid detection signal is continuously maintained for a predetermined time or more. Sometimes, it is determined that the first and second electrodes have contacted the liquid surface.

The automatic analyzer according to the third aspect of the present invention comprises:
A liquid level detecting device according to any one of claims 1 to 3 is provided to analyze the liquid.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A liquid level detecting device, a liquid level detecting method, and an automatic analyzer equipped with the liquid level detecting device according to one embodiment of the present invention will be described below with reference to the drawings.
In each of the drawings, components that perform the same or similar functions are denoted by the same reference numerals. The liquid level detecting method is executed by the liquid level detecting device. The automatic analyzer 101 having the liquid level detecting device according to the present embodiment is different from the conventional automatic analyzer 20 in that a liquid level detecting electrode 61 is provided instead of the conventional liquid level detecting electrode 10 and the conventional control is performed. The difference is that a control device 81 is provided instead of the device 8.
The liquid level detection electrode 61, the nozzle 3, and the control device 8
1 constitutes the liquid level detecting device 91. Other configurations are
Since this is the same as the case of the automatic analyzer 20 described above, only the liquid level detection electrode 61 and the control device 81 will be described below, and the description of the other components will be omitted. Although the operation of the automatic analyzer 101 will be described later in detail, when the liquid level detection electrode 61 corresponding to the liquid level detection electrode 10 and the nozzle 3 come into contact with the test solution 2, the test solution 2
There is no change in the basic operation of detecting the liquid level 2a by obtaining continuity between them through the interface.

The liquid level detecting electrode 61 will be described. The liquid level detection electrode 61 is an elongated stainless steel rod-like electrode having a diameter of about 1 mm made of metal, similar to the liquid level detection electrode 10 described above. As shown in FIG. 26 is tapered so that it can be easily split. Further, the liquid level detection electrode 61 is coated with a silicon material on all other surfaces 63 except for the conductive portion 62 at the leading end. Therefore, the only part of the liquid level detection electrode 61 that can be electrically contacted with the test solution 2 is the conductive part 62 where the coating is not applied and the surface of the stainless steel is exposed. By forming the conductive portion as small as possible in this way, even when the nozzle 3 is in contact with the bubble 25 or the film 26, the liquid level detection electrode 61 is unnecessarily electrically connected to the bubble 25 or the film 26. Contact can be prevented. The liquid level detection electrode 61
The length III of the conductive portion 62 along the direction in which the liquid level detection electrode 61 extends from the foremost end is about 0.5 mm.

The liquid level detecting electrode 61 and the bubble 25
The means for preventing unnecessary electrical contact with the coating 26 and the film 26 is not limited to the application of the coating. For example, a portion corresponding to the coating surface 63 such as a plastic or rubber material may be used. A method for covering the sheath of a non-conductive material, the liquid level detecting electrode body is formed of a rod-shaped member made of an insulator, and a conductive portion 62 is provided at the foremost portion of the rod-shaped member. Various methods are conceivable, such as a method of electrically connecting the conductive portion 62 and the control device 81 while keeping the insulation property. Further, at least the liquid level detection electrode 61 does not need to be in the shape of a rod, and may be in any form as long as the conductive part 62 is provided at the tip of the liquid contact part that comes into contact with the liquid level 2a of the test solution 2. . or,
The coating material is not limited to the silicon material described above, and the liquid level detection electrode 61 is a component that comes into contact with the test solution 2; therefore, any material having water resistance, water repellency, and scratch resistance may be used. .

Further, in the liquid level detecting electrode 61 of the present embodiment,
Although the tip portion has a pointed shape, a liquid level detection electrode 65 having a flat end surface 64 as shown in FIG. 3 may be used.
In this case, the conductive portion is preferably only the end surface 64, but may be the end surface 64 and a peripheral portion 66 of about 0.5 mm from the end surface 64 along the extending direction. In the present embodiment, the coating is applied to the liquid level detection electrode 61.
It is preferable that both the nozzle 1 and the nozzle 3 be subjected to the above-mentioned treatment such as coating. In this case, the nozzle 3 has an end face 3a at the tip end.
Preferably, only the conductive portion 62 is used, and the other portions are made nonconductive by, for example, applying the above-mentioned coating.
Further, as shown in FIG. 1, the reason why the nozzle 3 extends slightly longer than the liquid level detection electrode 61 is that the conductive portion 62 of the liquid level detection electrode 61 is electrically connected to the liquid level 2 a of the test liquid 2. Sometimes, the suction port opened on the end face 3a of the nozzle 3 has already entered the test solution 2 so that the test solution 2 can be sucked.

Next, the control device 81 will be described. The control device 81 includes an integration circuit 82 in addition to the control portion that controls the operation of the automatic analyzer 20 as described above. The reason for providing the integration circuit 82 is as follows. That is, in the present embodiment, as described above, only the conductive portion 62 of the liquid level detection electrode 61 can be electrically contacted with the test solution 2 and unnecessarily electrically contacted with the bubble 25 and the film 26 as much as possible. However, the conductive portion 62 comes into contact with the bubble 25 or the film 26 and the liquid level detecting electrode 6
In some cases, a voltage change is sent from the nozzle 1 and the nozzle 3 to the control device 81. However, since the liquid level detection electrode 61 and the nozzle 3 are moved by the arm 9a, the bubble 25
The above voltage change due to the film 26 is a transient phenomenon. Therefore, when the conductive portion 62 comes into contact with the bubble 25 or the film 26 so that the controller 81 does not mistakenly think that the liquid level detection electrode 61 and the nozzle 3 have contacted the liquid level 2a based on such a voltage change. The voltage change sent from the nozzle 3 and the liquid level detection electrode 61 to the control device 81 is moderated so that the transient voltage change is not determined to be liquid level detection.
The integration circuit 82 was provided. In the case where the integrating circuit 82 is simply provided in the conventional liquid level detecting device having the conventional liquid level detecting electrode 10 which is not coated, the liquid level detecting electrode 10 is obtained by contact between the bubble 25 and the film 26. Similarly, in the case of both the bubble 25 and the film 26, the resulting voltage change has a gradual rise as shown in FIG. 4, and it is difficult to determine at which time of the rise the liquid level was detected. There is. Further, in the present embodiment, as described above, the conductive portion 62 comes into contact with the bubble 25 or the film 26 and sends a voltage change from the liquid level detection electrode 61 and the nozzle 3 to the control device 81. You may make it transmit a current change.

Further, a threshold value is set in the control device 82 of the present embodiment so that the liquid level 2a is not erroneously recognized based on a voltage change caused by the bubbles 25 and the film 26. That is, as shown in FIG. 5, when there is no bubble 25 or film 26, the waveform 11
1, almost simultaneously with the detection of the liquid level 2a by the nozzle 3 and the liquid level detection electrode 61, the nozzle 3 and the liquid level detection electrode 6
1 sends a voltage of about 1.7 V to the control device 81. On the other hand, when the bubble 25 is detected, the voltage sent from the nozzle 3 and the liquid level detection electrode 61 to the control device 81 has the waveform 1
As shown in FIG. 12, the voltage instantaneously increases to about 1 V, and then gradually increases to the above-mentioned voltage value of about 1.7 V. Membrane 26
Is detected, as shown in the waveform 113,
There is only a voltage rise of V. Therefore, it can be understood that the threshold value should be set to about 1 V in order to prevent the detection of the film 26 from being erroneously recognized as the detection of the liquid level 2 a.
Further, it can be seen that the threshold value should be set to about 1.3 V so that the detection of the bubble 25 is not erroneously recognized as the detection of the liquid level 2a. Therefore, in the present embodiment, the threshold value is set to 1.5 V so that the detection of the bubbles 25 and the film 26 is not mistaken for the detection of the liquid level 2a.

The automatic analyzer 101 constructed as described above
Will be described below with reference to FIG. The basic operation of the automatic analyzer 101 is the same as the operation of the automatic analyzer 20 described with reference to FIG. Therefore, only the operation different between the two, that is, step 103 shown in FIG. 6 corresponding to step 3 shown in FIG. 9 will be described below. In step 2, the liquid level detection electrode 61 and the nozzle 3 descend to the test solution 2 side. At this time, the conductive portion 62 of the liquid level detection electrode 61 and the nozzle 3 may come into contact with the bubble 25 or the film 26 of the test solution 2, but as described above, the conductive portion 62 of the liquid level detection electrode 61 Since it is the foremost part of the detection electrode 61,
The bubbles 25 and the film 26 are not mistaken for the liquid level 2a. or,
The conductive portion 62 of the liquid level detection electrode 61 and the nozzle 3 come into contact with the bubbles 25 and the film 26, and the liquid level detection electrode 61 and the nozzle 3
In consideration of a case where a voltage signal is transmitted from the control device 81, the control device 81 has the integration circuit 82 as described above. Therefore, in step 103, the voltage value sent from the liquid level detection electrode 61 and the nozzle 3 to the control device 81 is integrated by the integration circuit 82, and when the integration amount exceeds the above-described threshold value, the control device 81 Controls the arm driving device 9 to stop the lowering operation of the arm 9a as step 4. Therefore, the lowering of the liquid level detection electrode 61 and the nozzle 3 stops, and at this time, the nozzle 3
Is in a state of being in contact with the liquid surface 2a of the test solution 2 or in a state of entering the test solution 2 slightly more than the liquid surface 2a.
The integrating circuit 82 integrates only the voltage signal supplied within a predetermined time. Therefore, even if a plurality of voltage signals detected by the film 26 as shown by the waveform 113 in FIG.
Is canceled, and the integrated value obtained by detecting the plurality of films 26 does not exceed the threshold value.

As described above, the surface of the liquid level detecting electrode 61 is coated except for the conductive portion 62, and the control device 81 is provided with the integrating circuit 82. Can accurately detect the liquid level 2a of the test solution 2 in the container 1 irrespective of the presence of the bubbles 25 and the film 26.

In the present embodiment, as described above, the control device 81 has the integration circuit 82, but without the integration circuit 82, the operation program stored in the control device 81 detects the liquid level 2a. Can also be determined. Note that, even in the case of the processing by the operation program, the basic operation in the automatic analyzer 101 is not different from the case described above. That is, the operation in the case of the processing by the operation program shown in FIG. 7 is different from the operation in the case of using the integration circuit 82 shown in FIG. 6 in the step 103 of FIG. Therefore, in the operation in the case of the processing by the operation program, as shown in FIG. 7, steps 113 and 114 are provided instead of step 103.
Therefore, steps 113 and 114 will be described below using the automatic analyzer 101 as an example.

As described with reference to FIG. 5, when the liquid level 2a of the test solution 2 is detected, a voltage of about 1.7 V is continuously applied as shown by a waveform 111, and the liquid level detection electrode 61 and the nozzle 3 Is supplied to the controller 81 as a liquid detection signal. Therefore, in step 113, utilizing this fact, it is determined whether or not the liquid detection signal when the liquid level 2a of the test solution 2 is detected, for example, the voltage of about 1.7 V is continuously detected for a predetermined time. Is determined by the control device 81. And
When the signal at the time of detecting the liquid level 2a of the test solution 2 is continuously detected for a predetermined time, the process proceeds to step 4, while
If the above signal has not been detected for a predetermined time, the process proceeds to step 114. In step 114, it is determined whether the arm 9a, that is, the liquid level detection electrode 61 and the nozzle 3 have been lowered to the lower limit position. Then, the liquid level detection electrode 6
When the nozzle 1 and the nozzle 3 have not descended to the lower limit positions, the process returns to step 113. On the other hand, when the nozzles 3 and 3 have descended to the lower limit position, it is determined that the test solution 2 does not exist in the container 1 and the process proceeds to step 9. . Step 1 like this
Storing the operation program including the control circuits 13 and 114 in the control device 81 enables the control of the test solution 2 without the integration circuit 82.
Liquid level 2a can be accurately detected.

In each of the automatic analyzers 101 described above,
The liquid level detection electrode 61 and the nozzle 3
Was lowered to detect the liquid level 2a. Conversely, the liquid level detecting electrode 61 and the nozzle 3 were fixed, and the container 1 containing the test liquid 2 was moved up and down to lower the liquid level 2a. Detection can also be performed.

[0022]

As described in detail above, according to the liquid level detecting device of the first aspect, the liquid level detecting method of the second aspect, and the automatic analyzer of the third aspect of the present invention, the liquid level is detected. A conductive portion is provided at the tip of the electrode, and the liquid level is detected when the signal sent from the electrode continuously maintains a predetermined level for a predetermined time or more. The detection of bubbles and films of the liquid is not erroneously recognized as the liquid level, and the liquid level can be accurately detected.

[Brief description of the drawings]

FIG. 1 is a diagram showing a structure of an automatic analyzer including a liquid level detecting device according to an embodiment of the present invention.

FIG. 2 is an enlarged view of a tip portion of a liquid level detection electrode provided in the automatic analyzer shown in FIG.

FIG. 3 is an enlarged view of a tip of another embodiment of the liquid level detection electrode provided in the automatic analyzer shown in FIG. 1;

FIG. 4 is a graph showing an output signal from an integration circuit to which a signal output from a conventional liquid level detection device is supplied.

FIG. 5 is a waveform showing an output signal of an electrode provided in the automatic analyzer shown in FIG.

FIG. 6 is a flowchart showing an operation when the automatic analyzer shown in FIG. 1 has an integrating circuit.

FIG. 7 is a flowchart showing an operation when the automatic analyzer shown in FIG. 1 detects a liquid level by executing an operation program.

FIG. 8 is a diagram showing the structure of a conventional automatic analyzer.

FIG. 9 is a flowchart showing the operation of the automatic analyzer shown in FIG.

FIG. 10 is a view showing a liquid surface, bubbles, and a film in a container.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Container, 2 ... Test solution, 2a ... Liquid level, 3 ... Nozzle, 61 ...
Liquid level detecting electrode, 62: conductive portion, 63: coating surface, 81: control device, 82: integrating circuit, 91, 92 ...
Liquid level detecting device, 101 ... automatic analyzer.

Claims (6)

[Claims] 1. A liquid level detecting device for detecting a liquid level (2a) of a liquid (2) collected in a container (1), wherein the first and second electrodes contact the liquid in the container. And at least one of the first and second electrodes (61, 3) having a conductive portion (62) at the tip of a constituent member of the electrode; the liquid and the conductive member; Becomes conductive, the first
And a signal output from the second electrode is supplied, and the supplied signal is a liquid supplied when the first and second electrodes come into contact with the liquid instead of a bubble or a film formed in the liquid. A control device (81) that determines that the first and second electrodes have contacted the liquid surface when the detection signal is a detection signal and the liquid detection signal is continuously maintained for a predetermined time or more;
A liquid level detection device comprising: 2. A method according to claim 1, wherein the first electrode and the second electrode are each provided with a non-conductive material on an outer peripheral side surface of a conductive core member, and the front end surface of the core member or the vicinity thereof including the end surface is the conductive material. The liquid level detecting device according to claim 1, wherein the liquid level detecting device is an operable portion. 3. The control device according to claim 2, wherein the supplied signal is replaced by determining that the electrode has contacted the liquid surface when the liquid detection signal is continuously maintained for a predetermined time or more. 3. The liquid level detecting device according to claim 1, wherein the integrated signal is integrated, and when the integrated signal exceeds a threshold level, it is determined that the electrode has contacted the liquid level. 4. An automatic analyzer comprising the liquid level detecting device according to claim 1 and analyzing the liquid. 5. A liquid level detecting device for detecting a liquid level (2a) of a liquid (2) collected in a container (1), the first and second liquid level detecting devices being in contact with the liquid in the container. And at least one of the electrodes is implemented in a liquid level detection device including first and second electrodes (61, 3) having a conductive portion (62) at the tip of a constituent member of the electrode. In the liquid level detection method, when the liquid and the conductive member come into contact with each other, the first and second electrodes having the conductive portion at the tip end, instead of bubbles or films formed in the liquid. A liquid detection signal that is transmitted when the liquid comes into contact with the liquid is transmitted. When the liquid detection signal is continuously maintained for a predetermined time or more, the first and second electrodes contact the liquid surface. Determining a liquid level. 6. A signal transmitted from the first and second electrodes instead of the step of determining that an electrode has contacted the liquid surface when the liquid detection signal has been continuously maintained for a predetermined time or more. 6. The liquid level detection method according to claim 5, wherein the integration is performed, and when the integrated signal exceeds the threshold level, it is determined that the first and second electrodes have contacted the liquid level.