JP2009036666A - Liquid quantity detection device and automatic analyzer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid quantity detection device and an automatic analyzer capable of detecting accurately a liquid quantity, even when a sound wave generation source is unstable in time or in temperature, or when an environmental sound is not always constant. <P>SOLUTION: In the liquid quantity detection device and the automatic analyzer, the quantity of liquid in a container is detected by utilizing a resonance phenomenon of a sound wave. The liquid quantity detection device 20 includes a receiver 24 for measuring a resonance sound of an air column in the container 7 caused by the sound wave emitted from a sound wave generation source 21, a reference receiver 27 for measuring a resonance sound of an air column in a reference container caused by the sound wave emitted from the sound wave generation source simultaneously with the receiver, detectors 25, 28 for detecting the frequency of each resonance sound measured by the receiver and the reference receiver, and a liquid quantity determination part 26 for determining the quantity of the liquid in the container based on the detected frequency of each resonance sound. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a liquid amount detection device and an automatic analyzer.

  Conventionally, a liquid amount detection device for a tank is known as a liquid amount detection device for detecting the amount of liquid in a container (see, for example, Patent Document 1). This liquid level detection device detects the maximum level of reverberant sound of a sound wave emitted from a speaker provided in a liquid injection pipe of a container, and detects the maximum level of Helmholtz based on the frequency of the sound wave when the reverberant sound reaches the maximum level. The liquid volume is calculated by the resonance principle.

JP-A-8-327429

  By the way, in the liquid amount detection device of Patent Document 1, when the frequency of the emitted sound wave changes irregularly with time, or changes irregularly with temperature, the speaker becomes unstable in time or temperature, Since the value of the factor for calculating the liquid amount changes, there is a problem that the detection accuracy of the liquid amount changes. The same problem occurs when the environmental sound (noise) that affects the signal detected by the microphone is not constant.

  The present invention has been made in view of the above, and even if the sound wave generation source becomes unstable in time or temperature, and even if the environmental sound is not always constant, the liquid amount can be detected with high accuracy. It is an object of the present invention to provide a liquid amount detection device and an automatic analyzer that can be used.

  In order to solve the above-described problems and achieve the object, a liquid amount detection device of the present invention is a liquid amount detection device that detects the amount of liquid in a container using a resonance phenomenon of sound waves, and generates a sound wave. Measuring means for measuring the resonance sound of the air column in the container due to the sound wave emitted from the source, and reference measuring means for simultaneously measuring the resonance sound of the air column in the reference container due to the sound wave emitted from the sound wave generating source. Detection means for detecting the frequency of the resonance sound measured by the measurement means and the reference measurement means; and a liquid volume determination means for determining the amount of the liquid in the container based on the detected frequency of each resonance sound , Provided.

  Moreover, the liquid amount detection device of the present invention is characterized in that, in the above-mentioned invention, a control means for controlling a frequency of a sound wave emitted from the sound wave generation source is provided.

  In order to solve the above-described problems and achieve the object, the automatic analyzer of the present invention stirs and reacts a sample and a reagent, measures the optical characteristics of the reaction solution, and analyzes the reaction solution. An automatic analyzer that detects the amount of the sample or the reagent dispensed into the container using the liquid amount detection device according to claim 1.

  Moreover, the automatic analyzer of the present invention is characterized in that, in the above invention, the liquid amount detecting device uses an operating sound emitted by an operating part of the automatic analyzer as a sound wave emitted from the sound wave generation source. .

  Further, the automatic analyzer according to the present invention is the above-described invention, wherein the liquid amount detecting device dispenses the sample after the sample or the reagent is dispensed into the container or the reference container. Alternatively, the amount of the reagent is detected.

  The liquid amount detection device of the present invention is measured by a measuring means for measuring the resonance sound of the air column in the container, a reference measuring means for simultaneously measuring the resonance sound of the air column in the reference container, the measuring means and the reference measuring means. A detection means for detecting the frequency of each resonance sound, and a liquid volume determination means for determining the amount of liquid in the container based on the frequency of each resonance sound, and the automatic analyzer of the present invention provides the liquid volume detection Since the amount of the sample or reagent dispensed into the container is detected using the device, even if the sound source is unstable in terms of time or temperature, and even if the environmental sound is not always constant, the liquid There is an effect that the amount can be accurately detected.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of a liquid amount detection device and an automatic analyzer according to the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic configuration diagram showing a liquid amount detection device and an automatic analyzer according to the present invention. FIG. 2 is a schematic configuration diagram showing the liquid amount detection device of the present invention together with a reaction vessel. FIG. 3 is a diagram for explaining the relationship between the column length of the reaction vessel and the wavelength of the resonance frequency.

  As shown in FIG. 1, the automatic analyzer 1 includes a sample table 3, a sample dispensing mechanism 5, a reaction wheel 6, a stirring device 8, a photometric device 9, a cleaning device 11, a reagent dispensing mechanism 12, and a work table 2. A reagent table 13 is provided, and in the vicinity of the sample dispensing mechanism 5, a sound wave generation source 21, a wave receiver 24, and a reference wave receiver 27 of the liquid amount detection device 20 are arranged.

  As shown in FIG. 1, the sample table 3 is rotated in the direction indicated by the arrow by the driving means, and a plurality of storage chambers 3 a are provided on the outer periphery at regular intervals along the circumferential direction. In each storage chamber 3a, a sample container 4 storing a sample is detachably stored.

  The sample dispensing mechanism 5 is a means for dispensing a sample into a plurality of reaction containers 7 held by the reaction wheel 6, and as shown in FIG. 1, the sample dispensing mechanism 5 of the sample table 3 is provided by a dispensing nozzle 5a (see FIG. 2). Dispensing is performed by sequentially sucking samples from the plurality of sample containers 4 and discharging the sucked samples to the reaction container 7. At this time, the specimen dispensing mechanism 5 has a cleaning tank (not shown) for cleaning the inside and outside of the dispensing nozzle 5a on the movement path of the dispensing nozzle 5a.

  The reaction wheel 6 is rotated in a direction indicated by an arrow in FIG. 1 by driving means different from the sample table 3, and a plurality of concave portions 6a are provided at equal intervals along the circumferential direction on the outer periphery. The reaction wheel 6 has openings (not shown) through which measurement light passes on both radial sides of the recesses 6a. For example, the reaction wheel 6 rotates counterclockwise (1 turn-1 reaction vessel) / 4 minutes in one cycle and rotates clockwise by one of the recesses 6a in four cycles. In the vicinity of the outer periphery of the reaction wheel 6, a stirring device 8, a photometric device 9 and a cleaning device 11 are arranged.

  The reaction container 7 is a very small container having a capacity of several μL to several hundred μL, and is made of a transparent material that transmits 80% or more of the light contained in the analysis light emitted from the light source of the photometric device 9, for example, heat resistant glass. It is a square tube-shaped cuvette having an opening 7a (see FIG. 2) in the upper part made of synthetic resin such as glass, cyclic olefin or polystyrene. The reaction vessel 7 is disposed in the concave portion 6a of the reaction wheel 6 with the opposite side wall directed in the radial direction.

  The stirring device 8 is disposed on the reagent table 13 side in the vicinity of the outer periphery of the reaction wheel 6 and stirs the liquid held in the reaction vessel 7 in a non-contact manner using sound waves, or directly stirs the liquid with a stirring rod.

  The photometric device 9 has a light source that emits analysis light for analyzing the liquid held in the reaction vessel 7 and a light receiver that splits and receives the analysis light transmitted through the liquid. In the photometric device 9, the light source and the light receiver are arranged at positions facing each other in the radial direction across the recess 6 a of the reaction wheel 6.

  The cleaning device 11 is disposed between the photometric device 9 in the vicinity of the outer periphery of the reaction wheel 6 and the sample dispensing mechanism 5, and has a discharge means for discharging the liquid and the cleaning liquid from the reaction container 7 and a cleaning liquid dispensing means. ing. The cleaning device 11 dispenses the cleaning liquid after discharging the liquid after photometry from the reaction container 7 after photometry. The cleaning device 11 cleans the inside of the reaction vessel 7 by repeating the dispensing and discharging operations of the cleaning liquid a plurality of times. The reaction container 7 washed in this way is used again for analysis of a new specimen.

  The reagent dispensing mechanism 12 is a means for dispensing a reagent into a plurality of reaction containers 7 held on the reaction wheel 6, and sequentially reacts the reagents from a predetermined reagent container 14 of the reagent table 13 as shown in FIG. Dispense into container 7.

  The reagent table 13 is rotated in a direction indicated by an arrow in FIG. 1 by a driving means different from the sample table 3 and the reaction wheel 6, and a plurality of storage chambers 13a formed in a fan shape are provided along the circumferential direction. In each storage chamber 13a, the reagent container 14 is detachably stored. Each of the plurality of reagent containers 14 is filled with a predetermined reagent corresponding to a test item, and an information recording medium (not shown) such as a barcode label for displaying information on the stored reagent is attached to the outer surface.

  Here, on the outer periphery of the reagent table 13, as shown in FIG. 1, information such as the type, lot, and expiration date of the reagent recorded on the information recording medium attached to the reagent container 14 is read and sent to the control unit 16. A reading device 15 for outputting is installed.

  The control unit 16 includes a sample table 3, a sample dispensing mechanism 5, a reaction wheel 6, a stirring device 8, a photometric device 9, a washing device 11, a reagent dispensing mechanism 12, a reagent table 13, a reading device 15, an analysis unit 17, and an input. For example, a microcomputer or the like that is connected to the unit 18, the display unit 19, the liquid amount detection device 20, and the like and has a storage function for storing analysis results is used. The control unit 16 controls the operation of each unit of the automatic analyzer 1 and stops the analysis work based on the information read from the record of the information recording medium when the reagent lot or expiration date is out of the installation range. Thus, the automatic analyzer 1 is controlled or a warning is issued to the operator.

  The analysis unit 17 is connected to the photometry device 9 via the control unit 16, analyzes the component concentration of the specimen from the absorbance of the liquid in the reaction container 7 based on the amount of light received by the light receiver, and analyzes the analysis result to the control unit 16. Output to. The input unit 18 is a part that performs an operation of inputting inspection items and the like to the control unit 16, and for example, a keyboard, a mouse, or the like is used. The display unit 19 displays analysis contents, alarms, and the like, and a display panel or the like is used.

  The liquid amount detection device 20 is a device that detects the amount of liquid in the reaction vessel 7 using a resonance phenomenon of sound waves, and as shown in FIG. 2, a sound wave generation source 21, a signal generator 22, and a control device. 23, a receiver 24, a detector 25, a liquid amount determination unit 26, a reference receiver 27, and a reference detector 28.

  The sound wave generation source 21 irradiates a sound wave having a sound bundle having a cross-sectional area larger than the opening area of the reaction container 7 toward the inside of the reaction container 7, and for example, an aerial ultrasonic element is used. At this time, if the sound wave generation source 21 can irradiate a sound wave having a sound bundle having a cross-sectional area larger than the opening area of the reaction vessel 7 into the reaction vessel 7, the area larger than the opening area of the reaction vessel 7. The sound source having a sound generation area smaller than the opening may be arranged in a plurality of arrays. Therefore, the sound wave emitted from the sound wave generation source 21 enters the reaction vessel 7 as a plane wave.

  At this time, the reaction vessel 7 causes an air column resonance phenomenon as a tube whose one end is closed by the frequency of the radiated sound wave. The resonance frequency of sound waves when air column resonance occurs is inversely proportional to the amount of liquid held, that is, the length of the air column existing above the liquid in the container, and the air column length is the resonance frequency of the fundamental mode. It is known to be 1/4 of the wavelength. For example, as shown in FIG. 3, in the case of an empty reaction vessel 7, the column length L0 + Δx above the liquid is 1/4 of the wavelength λ0 of the resonance frequency f0 of the fundamental mode (f0 = C / λ0, C When the air column length becomes Li + Δx by dispensing the liquid Lq, the air column length Li becomes 1/4 of the wavelength λi (<λ0) of the resonance frequency of the fundamental mode (fi = C). / Λi, fi> f0). Here, Δx is the length of the air column portion (opening end correction) that is vibrating out of the tube opening.

  For this reason, if the resonance frequency of the resonance sound generated by the resonance of the air column in the reaction vessel 7 when the frequency of the sound wave applied to the reaction vessel 7 is changed, the length of the air column can be determined. Therefore, if the internal dimensions of the reaction vessel 7 are measured in advance, the amount of liquid dispensed can be determined, and this is the principle of detecting the amount of liquid dispensed into the vessel in the present invention.

  The control device 23 is also used as the control unit 16 of the automatic analyzer 1 and controls the signal generator 22 to control the frequency of the sound wave emitted from the sound wave generation source 21 to the reaction vessel 7. Here, the control device 23 controls the signal generator 22 to change the frequency of the sound wave that the sound wave generation source 21 irradiates the reaction vessel 7 from the frequency fs to the frequency fe in a certain time as shown in FIG. Change the range by sweeping.

  The wave receiver 24 is a measuring unit that measures resonance sound generated by the resonance of the air column in the reaction vessel 7 by the sound wave emitted from the sound wave generation source 21. For example, the wave receiver using an aerial ultrasonic element. Is used. The reference receiver 27 receives a resonance sound generated by the resonance of an air column in an undispensed empty reaction vessel 7 (hereinafter referred to as “reference vessel”) by the sound wave incident from the sound wave generation source 21. Reference measuring means for measuring at the same time as the detector 24, and the same as the receiver 24 is used.

  The detector 25 is a detection means such as a signal analyzer, an FFT analyzer, or a multimeter that detects the frequency of the resonance sound measured by the receiver 24, and detects the amplitude A of the sound wave that the sound wave source 21 irradiates the reaction vessel 7. By obtaining the amplitude ratio P / A, which is the ratio of the amplitude P of the resonance sound generated by the resonance of the air column in the reaction vessel 7, the amplitude ratio P / A is maximized, that is, the amplitude P of the resonance sound is maximized. Resonance frequency is detected. The reference detector 28 is reference detection means for detecting the frequency of the resonance sound measured by the reference receiver 27, and the same detector as the detector 25 is used.

  The liquid amount determination unit 26 determines the amount of liquid held in the reaction vessel 7 based on the resonance frequency detected by the detector 25 and the detector 28, and for example, a microcomputer or the like is used. At this time, the liquid amount detection device 20 dispenses various amounts of liquid into the reference vessel 7A and the reaction vessel 7 in advance and measures the resonance frequency for the reaction vessel 7 used in the automatic analyzer 1, and the liquid amount is zero. The relationship between the resonance frequency of the reference container 7A, the difference between the resonance frequencies of the reaction container 7 and the liquid volume is stored in the liquid volume determination unit 26 as basic data.

  At this time, the liquid volume determination unit 26 compares the difference between the resonance frequency detected by the detector 25 and the resonance frequency detected by the reference detector 28 with the basic data, so that the liquid dispensed into the reaction vessel 7 Determine the volume. For this reason, the liquid amount detection device 20 can easily detect the liquid amount by omitting the effort of correcting the opening end. However, the liquid amount determination unit 26 may calculate the length of the air column of the reaction vessel 7 and thus the amount of dispensed liquid based on the actually measured resonance frequency.

  The automatic analyzer 1 of the present invention is configured as described above. For example, the reagent dispensing mechanism 12 is provided with a reagent container 14 in a plurality of reaction containers 7 conveyed along the circumferential direction by a reaction wheel 6 that rotates counterclockwise. Dispense the reagents in order. The reaction container 7 into which the reagent has been dispensed is conveyed along the circumferential direction by the reaction wheel 6, and the specimen is sequentially dispensed from the plurality of specimen containers 4 held on the specimen table 3 by the specimen dispensing mechanism 5.

  Then, the reaction container 7 into which the specimen has been dispensed is conveyed to the stirring device 8 by the reaction wheel 6, and the dispensed reagent and specimen are sequentially stirred and reacted. The reaction solution in which the sample and the reagent have reacted in this way passes through the photometric device 9 when the reaction wheel 6 rotates again, and the analysis light emitted from the light source is transmitted. At this time, the reaction solution of the reagent and the sample in the reaction container 7 is sidelighted by the light receiver, and the component concentration and the like are analyzed by the control unit 16. After the analysis is completed, the reaction vessel 7 is washed by the washing device 11 and then used again for analyzing the specimen.

  At this time, the liquid amount detection apparatus 20 of the present invention can easily detect the amount of liquid in the reaction container 7 after the sample is dispensed as follows using the resonance phenomenon of sound waves. .

  First, the liquid amount detection device 20 controls the signal generator 22 by the control device 23, and generates a sound wave having a sound bundle having a cross-sectional area larger than the sum of the opening areas of the reaction vessel 7 and the reference vessel 7 </ b> A from the sound wave generation source 21. Irradiation is performed toward the opening 7a of the reaction vessel 7 and the reference vessel 7A. At this time, the control device 23 controls the signal generator 22 to change the frequency of the sound wave emitted from the sound wave generation source 21 within a certain range.

  Next, the resonance sound generated by the resonance of the air column in the reaction vessel 7 by the irradiated sound wave is measured by the receiver 24 and the reference receiver 27, and the measured resonance signal is detected by the detector 25 and the reference detection, respectively. To the device 28. At this time, the reference receiver 27 measures the resonance sound simultaneously with the receiver 24. Next, based on the resonance signal input from the receiver 24 and the reference receiver 27, the frequency of the resonance is detected by the detector 25 and the reference detector 28.

  Then, based on the difference between the resonance frequency detected by the detector 25 and the resonance frequency detected by the reference detector 28, the liquid volume determination unit 26 determines the liquid volume of the liquid in the reaction vessel 7, and the determined liquid volume Is output to the controller 23 as a liquid amount signal.

  Here, as shown in FIG. 1, the sample dispensing mechanism 5 sequentially dispenses 1 μL, 2 μL, 10 μL, and 20 μL of liquid into the reaction container 7, and the frequency of the sound wave emitted from the sound wave source 21 is 80 to 80. While changing in the range of 83 kHz, irradiation is performed toward the reference container 7A (liquid amount 0 μL) before sample dispensing and the opening 7a of the reaction container 7 after sample dispensing, and the amplitude ratio P is detected by the detector 25 and the reference detector 28. / A was determined. As a result, as shown in FIG. 5, the reaction vessel 7 has a frequency characteristic in which the resonance frequency, which is the peak of the amplitude ratio P / A, increases as the liquid volume increases. Was consistent with the air column resonance results. Here, the peak of the amplitude ratio P / A indicates that the amplitude P of the resonance sound generated by the resonance of the air column in the reaction vessel 7 or the reference vessel 7A is the maximum with respect to the amplitude A of the radiated sound wave. The frequency of each peak indicates the resonance frequency.

  However, when the resonance frequency is detected by the liquid volume detection device 20, the frequency resolution and sensitivity to the liquid volume depend on the frequency band of the sound wave to be used, but the resonance of the air column is spaced over a plurality of frequency bands. Occur. For this reason, when the resonance frequency is detected by the liquid amount detection device 20, the frequency band of the sound wave to be used can be selected from a plurality of frequency bands. Therefore, the frequency band of the sound wave to be used is set so as to be optimal according to the specifications such as the internal dimensions of the reaction vessel 7 and the reference vessel 7A, the dispensed amount, the price of the liquid amount detection device 20, and the like. For example, the liquid amount detection device 20 can use a speaker or a receiver 24 as a low-frequency sound source 21 and a microphone or the like when a low frequency band such as an audible range is selected as the frequency band of a sound wave to be used. When a high frequency band is selected, frequency resolution and liquid volume detection accuracy can be improved.

  The liquid amount detection device 20 can easily detect the amount of liquid dispensed into the reaction container 7 by utilizing the resonance phenomenon of sound waves. At this time, the receiver 24 and the reference receiver 27 simultaneously measure the resonance generated by the sound wave incident from the sound source 21. For this reason, even if the sound wave generation source 21 is unstable in terms of time or temperature, such as the frequency of the emitted sound wave irregularly changes, the liquid level detection device 20 is not always constant in environmental sound. However, since the receiver 24 and the reference receiver 27 measure the resonance sound simultaneously, that is, under the same measurement conditions, the difference between the two detection signals can be evaluated. Can be detected with high accuracy.

  Here, when the liquid volume detected by the liquid volume detection device 20 from the resonance frequency is outside the predetermined range, the automatic analyzer 1 gives a warning to the display unit 19 that the liquid volume is abnormal. You may display below.

(Modification 1)
Here, as shown in FIG. 6, the automatic analyzer 1 does not have to provide the sound wave generation source 21 of the liquid amount detection device 20. In this case, the liquid amount detection device 20 includes the sample table 3, the sample dispensing mechanism 5, the reaction wheel 6, the stirring device 8, the washing device 11, the reagent dispensing mechanism 12, the reagent table 13, and the like of the automatic analyzer 1. Are used as the sound wave generation source, and the operation sound generated by these operation parts is used as the sound wave emitted from the sound wave generation source. For this reason, the liquid amount detection device 20 does not require the signal generator 22.

  The automatic analyzer 1 generates an operating sound in a wide area extending from an audible sound to an ultrasonic range. For example, in an automatic analyzer for biochemical analysis, the audible range is mainly in a range of 500 Hz to 1 kHz. Operating noise is generated. For this reason, the automatic analyzer 1 eliminates the need for the sound wave generation source 21 and the signal generator 22 by using the operation sound generated by the operation unit, and can save space and reduce costs.

  In this case, the liquid amount detection device 20 simultaneously measures the resonance sound generated in the reaction container 7 and the reference container 7A by the operation sound generated by the operation unit by the receiver 24 and the reference receiver 27. For this reason, even if the sound wave generation source 21 is unstable in terms of time or temperature, the liquid amount detection device 20 can detect the liquid amount in the reaction container 7 with high accuracy by detecting the resonance frequency. However, the liquid amount detection device 20 may detect only the presence or absence of liquid in the reaction vessel 7 because the amplitude ratio shown in FIG.

(Modification 2)
Further, as shown in FIG. 7, the automatic analyzer 1 arranges a sound wave generation source 21, a wave receiver 24, and a reference wave receiver 27 of the liquid amount detection device 20 in the vicinity of the reagent dispensing mechanism 12, and a reagent container. Fourteen reagent remaining amounts may be detected. At this time, the reagent table 13 is arranged adjacent to the reagent container 14 that consumes a large amount of reagent, and a predetermined rotation is made using the timing at which the reference container 14A moves to the position of the reference receiver 27. The remaining amount of the reagent container 14 is measured once every time.

  Here, the liquid amount detection device 20 of the present invention normally detects the liquid amount of the sample dispensed after the sample is dispensed by the sample dispensing mechanism 5. However, if the liquid to be detected is located inside the opening 7a of the reaction container 7, the liquid amount detection device 20 detects simultaneously with the dispensing of the sample Ls into the reaction container 7 by the dispensing nozzle 5a of the sample dispensing mechanism 5. It is also possible to do.

  Further, the control device 23 changed the frequency of the sound wave by sweeping a predetermined frequency range when changing the frequency of the sound wave applied to the reaction vessel 7 by the sound wave generation source 21. However, as shown in FIG. 8, the control device 23 may change the frequency of the sound wave applied to the reaction vessel 7 by modulating the range from the frequency fs to the frequency fe with a constant period.

  Furthermore, the reference container 7A demonstrated the case where the empty thing in which the liquid was not dispensed was used. However, the reference containers 7A and 14A may be those holding a predetermined amount of liquid.

  The liquid amount detection device 20 is provided with two detectors 25 and a reference detector 28 as resonance sound detection means, but the resonance sound measured by the receiver 24 and the resonance measured by the reference receiver 27. If the sound can be distinguished, the number of detectors may be one.

  Furthermore, although the automatic analyzer 1 has been described with respect to a single reagent table 13, the number of reagent tables may be two, and a plurality of units may be connected with the automatic analyzer 1 as one unit.

It is a schematic block diagram which shows the liquid quantity detection apparatus and automatic analyzer of this invention. It is a schematic block diagram which shows the liquid quantity detection apparatus of this invention with reaction container. It is a figure explaining the relationship between the air column length of a reaction container, and the wavelength of a resonant frequency. It is a time change figure of the frequency which shows an example which changes the frequency of the sound wave with which a reaction container is irradiated. It is the frequency characteristic figure of the amplitude ratio of the sound wave which the detector detected when irradiating the sound wave to each of the reaction containers into which different amounts of liquid were dispensed while changing the frequency in the range of 80 to 83 kHz. It is a schematic block diagram which shows the modification 1 of the automatic analyzer of this invention. It is a schematic block diagram which shows the modification 2 of the automatic analyzer of this invention. It is a time change figure of the frequency which shows the other example which changes the frequency of the sound wave irradiated to a reaction container.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Automatic analyzer 2 Work table 3 Specimen table 4 Specimen container 5 Specimen dispensing mechanism 6 Reaction wheel 7 Reaction container 7A Reference container 8 Stirrer 9 Photometer 11 Washing device 12 Reagent dispensing mechanism 13 Reagent table 14 Reagent container 14A Reference container DESCRIPTION OF SYMBOLS 15 Reading apparatus 16 Control part 17 Analysis part 18 Input part 19 Display part 20 Liquid quantity detection apparatus 21 Sound wave generation source 22 Signal generator 23 Control apparatus 24 Receiver 25 Detector 26 Liquid quantity determination part 27 Reference receiver 28 Reference Detector

Claims (5)

A liquid amount detection device that detects the amount of liquid in a container using a resonance phenomenon of sound waves,
A measuring means for measuring the resonance sound of the air column in the container by the sound wave emitted from the sound wave generation source;
Reference measuring means for simultaneously measuring the resonance sound of the air column in the reference container by the sound wave emitted from the sound wave generation source, and the measuring means;
Detecting means for detecting the frequency of each resonance sound measured by the measuring means and the reference measuring means;
A liquid amount determining means for determining the amount of liquid in the container based on the detected frequency of each resonance,
A liquid amount detecting device comprising:   The liquid amount detection device according to claim 1, further comprising a control unit that controls a frequency of a sound wave emitted from the sound wave generation source.   An automatic analyzer that analyzes a reaction liquid by stirring and reacting a specimen and a reagent, measuring an optical characteristic of the reaction liquid, and using the liquid amount detection device according to claim 1 to the container. An automatic analyzer that detects an amount of the sample or the reagent to be dispensed.   4. The automatic analyzer according to claim 3, wherein the liquid amount detection device uses an operation sound generated by an operation unit of the automatic analyzer as a sound wave emitted from the sound wave generation source.   The liquid amount detection device detects an amount of the sample or the reagent dispensed after any of the sample or the reagent is dispensed into the container or the reference container. 3. The automatic analyzer according to 3.

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