Pure water detection and concentration detection

Abstract

A method of use with a capacitance based detector, includes aspirating a predetermined volume of liquid from a container into a probe associated with the detector. The method further includes collecting an electric detection signal of the detector. The method also includes determining a property of the liquid other than a level of the liquid in the container based on the collected electric detection signal.

Description

PURE WATER DETECTION AND CONCENTRATION DETECTIONBACKGROUND

[0001] Clinical analyzers and / or immunoassays are well known in the art and are generally used for automated or semi-automated analysis of patient samples, such as blood, urine, spinal fluid, and the like. For testing and analyzing a patient sample, a specific component (for example, an antigen) is measured in the patient sample. Analysis of the patient sample involves general procedures, such as aspirating the patient sample from a sample vessel, dispensing the patient sample into a reaction vessel, aspirating a reagent from a reagent pack, dispensing the reagent into the reaction vessel, and so on. Such procedures are typically conducted by using one or more probes, such as a pipetting device (also referred to as a pipettor).

[0002] For many aspirating and dispensing procedures, it is important that the pipettor is periodically cleaned, such as to avoid cross contamination between different patient samples or different reagents. For example, in some instances, a portion of a patient sample may contact the pipettor as the pipettor dispenses the reagent into the reaction vessel, and may then be carried from the reaction vessel by the pipettor. Additionally or alternatively, a reagent pipettor comes into contact with different reagents (within a test pack and between test packs) which, if not properly cleaned off a pipettor may result in contamination between reaction vessels, from a reaction vessel to a reagent pack, or between different portions of a reagent pack. Thus, it may be important to cleanse the pipettor before the pipettor aspirates a sample or reagent and / or before the pipettor dispenses a sample or reagent into a reaction vessel. Any remnant of a prior fluid (reagent or patient sample) may lead to an erroneous result of the analyzer. In one example, for cleaning the pipettor, the pipettor aspirates a detergent liquid from a liquid storage container (e.g., bottle); then, the tip of the pipettor is moved into a wash tower, where an outside surface of the pipettor is sprayed with wash fluid (also referred to as cleaning fluid), and / or wash fluid is pumped through a proximal (e.g., top) portion of the pipettor onto an inside surface of the pipettor and drained into the wash tower. The detergent liquid maybe rinsed from the surfaces of the pipettor and drained into the wash tower by the wash fluid.

[0003] In some cases, a liquid storage container containing improper liquid contents may be inadvertently provided to the pipettor for aspiration of its contents, such as due to human error. For example, a liquid storage container containing a reagent such as deionized water may be inadvertently provided to the pipettor for aspiration prior to the pipettor moving to the wash tower for a cleaning procedure, instead of the appropriate detergent liquid. On the other hand, a liquid storage container containing a detergent liquid may be inadvertently provided to the pipettor for aspiration prior to the pipettor moving to the reaction vessel for a sample analysis procedure. It would be desirable to identify the type of fluid aspirated by the pipettor from the liquid storage container, such as to confirm that the pipettor has aspirated a detergent liquid (e.g., rather than a reagent such as deionized water) prior to cleaning at the wash tower; and / or to confirm that the pipettor has aspirated a reagent such as deionized water (e.g., rather than a detergent liquid) prior to dispensing at the reaction vessel.

[0004] In some cases, a concentration of the detergent liquid stored within a liquid storage container may diminish over time, such as due to volatilization of the detergent liquid within the liquid storage container. It would be desirable to confirm that the concentration of the detergent liquid that has been aspirated by the pipettor for a cleaning procedure is sufficiently high for effective cleaning of the pipettor at the wash tower.BRIEF DESCRIPTION OF THE DRAWINGS

[0005] While the specification concludes with claims which particularly point out and distinctly claim the invention, it is believed the present invention will be better understood from the following description of certain examples taken in conjunction with the accompanying drawings, in which like reference numerals identify the same elements and in which:

[0006] FIG. l is a schematic illustration of a portion of an example of an analyzer having a pipettor and a capacitance-based liquid level detector, showing various stages of a deionized water retrieval sequence;

[0007] FIG. 2 is a schematic illustration of the analyzer of FIG. 1, showing various stages of a detergent liquid retrieval sequence;

[0008] FIG. 3 is a schematic illustration of another portion of the analyzer of FIG. 1, showing various stages of a washing sequence using a low concentration detergent liquid;

[0009] FIG. 4 is a schematic illustration of the analyzer of FIG. 1, showing various stages of a washing sequence using a high concentration detergent liquid;

[0010] FIG. 5 depicts an example of a method of using the analyzer of FIG. 1; and

[0011] FIG. 6 depicts another example of a method of using the analyzer of FIG. 1.

[0012] The drawings are not intended to be limiting in any way, and it is contemplated that various embodiments of the invention may be carried out in a variety of other ways, including those not necessarily depicted in the drawings. The accompanying drawings incorporated in and forming a part of the specification illustrate several aspects of the present invention, and together with the description serve to explain the principles of the invention; it being understood, however, that this invention is not limited to the precise arrangements shown.DETAILED DESCRIPTION

[0013] Turning now to the drawings, FIGS. 1-4 schematically show examples of portions of an analyzer (10) for automated or semi-automated analysis of patient samples, such as blood, urine, spinal fluid, and the like. In the example shown, analyzer (10) includes a pipettor (12) configured to aspirate and / or dispense one or more fluids, such as a reagent (e.g., deionized water) and / or a detergent liquid. To that end, pipettor (12) includes a distal tip (14) configured to be moved into a first vessel in the form of a first liquid storagecontainer (16) (FIG. 1), to allow pipettor (12) to aspirate a first fluid such as a reagent in the form of deionized water (also referred to as pure water) (DW) from first liquid storage container (16); and further configured to be moved into a second vessel, such as a reaction vessel (e.g., cuvette), to allow pipettor (12) to dispense the deionized water (DW) into the second vessel. In addition, or alternatively, the deionized water (DW) may be used for any other suitable purpose rather than being used as a reagent, such as for rinsing. Distal tip (14) is also configured to be moved into a third vessel in the form of a second liquid storage container (18) (FIG. 2), to allow pipettor (12) to aspirate a second fluid such as a detergent liquid (DL) from second liquid storage container ( 18). Pipettor (12) of the present example is constructed from an electrically conductive material, such as an electrically conductive metal, and includes a generally cylindrical outside surface (19) and a generally cylindrical inside surface (not shown) that defines an inner lumen for receiving the fluids. While pipettor (12) of the present example is described for aspirating and / or dispensing a reagent in the form of deionized water (DW), it will be appreciated that pipettor (12) may alternatively be used for aspirating and / or dispensing any other suitable type of reagent or other fluid, such as a patient sample.

[0014] In the example shown, analyzer (10) further includes a capacitance-based liquid level detector (20) operatively coupled to pipettor (12) for detecting the level of a liquid within a vessel, such as the level of patient sample within a specimen container, and / or the level(s) of deionized water (DW) and detergent liquid (DL) within the respective liquid storage containers (16, 18). In this regard, each container (16, 18) may have an electrode (not shown) either integrally formed or otherwise associated therewith, and detector (20) may be configured to detect an electrostatic capacitance between such an electrode and pipettor (12), and to thereby detect a liquid level based on the change in electrostatic capacitance when pipettor (12) contacts the liquid within the container (16, 18). In some cases, each container (16, 18) may be constructed from an electrically conductive material, such as an electrically conductive metal, such that each container (16, 18) may itself serve as such an electrode. By way of further example, detector (20) may be configured and operable in accordance with at least some of the teachings of U.S. Pub. No. 2012 / 0003731,entitled “Analyzer and Method for Washing Dispenser Probe,” published January 5, 2012, the disclosure of which is incorporated by reference herein in its entirety.

[0015] As shown, detector (20) of the present example is in operative communication with a processor (22), such that detector (20) is operable to generate an electric detection signal (S) in response to the detected electrostatic capacitance and to communicate the generated electric detection signal (S) to processor (22). It will be appreciated that the responsiveness of detector (20) may be dependent on the particular capacitance and / or conductivity of the type of liquid contacted by pipettor (12) within containers (16, 18), such that the responsiveness of detector (20) may vary based on the type of liquid contacted by pipettor (12) within containers (16, 18). For example, detector (20) may be less responsive for the deionized water (DW) and may be more responsive for the detergent liquid (DL), which may include hydrochloric acid and / or sodium hypochlorite, and which may therefore contain ions providing substantially higher conductivity and / or substantially quicker capacitance changes. As described in greater detail below, processor (22) is configured to determine the type of liquid contacted by pipettor (12) based at least in part on such differences in responsiveness.

[0016] In this regard, processor (22) is configured to monitor the electric detection signal (S) generated by detector (20) during execution of a liquid retrieval sequence that includes a partial or “dummy” dispensing operation for determining the type of liquid retrieved from a particular container (16, 18). It will be appreciated that dummy dispensing operations can include dispensing a small amount of liquid (e.g., patient sample) that has been aspirated by pipettor (12) when pipettor (12) is raised after aspiration, such as to compensate for the lack of stability at distal tip (14) caused by the surface tension of the liquid in order to maintain distal tip (14) at a constant level. FIG. 1 illustrates an example of this sequence when pipettor (12) aspirates deionized water (DW) from first container (16), while FIG. 2 illustrates an example of this sequence when pipettor (12) aspirates detergent liquid (DL) from second container (18).

[0017] Referring now primarily to FIG. 1, an example of a liquid retrieval sequence in which pipettor (12) aspirates deionized water (DW) from first container (16) is shown. As shown in area 1A of FIG. 1, pipettor (12) is initially lowered into first container (16) that stores the deionized water (DW), with the deionized water (DW) contacting the electrode of first container (16); since pipettor (12) has not yet contacted the deionized water (DW) and is thus electrically isolated from the electrode of first container (16) at this stage, the electric detection signal (S) is off. As shown in area IB of FIG. 1, distal tip (14) of pipettor (12) contacts an upper surface of the deionized water (DW) during the lowering of pipettor (12); due to the deionized water (DW) having a substantially low capacitance and / or low conductivity (e.g., by comparison to the detergent liquid (DL)), the electrostatic capacitance change may occur slowly, such that the electric detection signal (S) remains off as the lowering of pipettor (12) continues. As shown in area 1C of FIG. 1, during the continued lowering of pipettor (12), distal tip (14) of pipettor (12) eventually penetrates the upper surface of the deionized water (DW) to a detection depth, at which point the electrostatic capacitance change is sufficient for the electric detection signal (S) to transition from off to on. As shown in area ID of FIG. 1, the lowering of pipettor (12) continues until distal tip (14) of pipettor (12) reaches an aspiration depth, which may be at a predetermined distance from the detection depth, and at which pipettor (12) aspirates a portion (e.g., a first predetermined volume) of the deionized water (DW) from first container (16); since pipettor (12) remains in contact with the deionized water (DW) remaining in the first container (16), the electric detection signal (S) remains on.

[0018] As shown in area IE of FIG. 1, after aspiration is complete, pipettor (12) is raised such that distal tip (14) of pipettor (12) eventually returns to the upper surface of the deionized water (DW); since pipettor (12) remains in contact with the deionized water (DW) remaining in the first container (16), the electric detection signal (S) remains on. As shown in area IF of FIG. 1, at a predetermined time after the start of raising pipettor (12) (or at a predetermined height above the aspiration depth), which may coincide with or occur slightly prior to distal tip (14) being in contact with the upper surface of the deionized water (DW), the dummy dispensing is initiated by discharging a portion (e.g., a secondpredetermined volume less than the first predetermined volume) of the aspirated deionized water (DW) from distal tip (14) of pipettor (12) during continued raising of pipettor (12); since pipettor (12) remains in contact with the deionized water (DW) remaining in the first container (16), via a continuous stream formed by the portion of the aspirated deionized water (DW) being dispensed, the electric detection signal (S) remains on. As shown in area 1G of FIG. 1, the dummy dispensing may eventually be ceased during continued raising of pipettor (12) such that a sufficient remainder of aspirated deionized water (DW) is retained within pipettor (12) for a subsequent sample analysis procedure; since pipettor (12) is no longer in contact with the deionized water (DW) remaining in the first container (16), the electric detection signal (S) transitions from on to off.

[0019] Referring now primarily to FIG. 2, an example of a liquid retrieval sequence in which pipettor (12) aspirates detergent liquid (DL) from second container (18) is shown. As shown in area 2A of FIG. 2, pipettor (12) is initially lowered into second container (18) that stores the detergent liquid (DL), with the detergent liquid (DL) contacting the electrode of second container (18); since pipettor (12) has not yet contacted the detergent liquid (DL) and is thus electrically isolated from the electrode of second container (18) at this stage, the electric detection signal (S) is off. As shown in area 2B of FIG. 2, distal tip (14) of pipettor (12) contacts an upper surface of the detergent liquid (DL) during the lowering of pipettor (12); due to the detergent liquid (DL) having a substantially high capacitance and / or high conductivity (e.g., by comparison to the deionized water (DW)), the electrostatic capacitance change may occur quickly, such that the electric detection signal (S) transitions from off to on substantially simultaneously with the contact between distal tip (14) and the upper surface of the detergent liquid (DL), thereby placing the detection depth substantially at the upper surface of the detergent liquid (DL). As shown in area 2C of FIG. 2, the lowering of pipettor (12) continues until distal tip (14) of pipettor (12) reaches an aspiration depth, which may be at a predetermined distance from the detection depth, and at which pipettor (12) aspirates a portion (e.g., the first predetermined volume) of the detergent liquid (DL) from second container (18); since pipettor (12) remains in contact with the detergent liquid (DL) remaining in the second container (18), the electricdetection signal (S) remains on. Since the detection depth for the detergent liquid (DL) is substantially at the upper surface of the detergent liquid (DL), the aspiration depth for the detergent liquid (DL) may be shallower than that for the deionized water (DW).

[0020] As shown in area 2D of FIG. 2, after aspiration is complete, pipettor (12) is raised such that distal tip (14) of pipettor (12) eventually returns to the upper surface of the detergent liquid (DL); since pipettor (12) remains in contact with the detergent liquid (DL) remaining in the second container (18), the electric detection signal (S) remains on. As shown in area 2E of FIG. 2, distal tip (14) of pipettor (12) is separated from the upper surface of the detergent liquid (DL) during the raising of pipettor (12); since pipettor (12) is no longer in contact with the detergent liquid (DL) and is thus electrically isolated from the electrode of second container (18) at this stage, the electric detection signal (S) transitions from on to off. As shown in area 2F of FIG. 2, at the predetermined time after the start of raising pipettor (12) (or at the predetermined height above the aspiration depth), which may occur substantially after distal tip (14) has separated from the upper surface of the detergent liquid (DL), the dummy dispensing is performed by discharging a portion (e.g., the second predetermined volume) of the aspirated detergent liquid (DL) from distal tip (14) of pipettor (12) during continued raising of pipettor (12); since pipettor (12) again contacts the detergent liquid (DL) remaining in the second container (18), via a continuous stream formed by the portion of the aspirated detergent liquid (DL) being dispensed, the electric detection signal (S) transitions from off to on. As shown in area 2G of FIG. 2, the dummy dispensing is eventually ceased during continued raising of pipettor (12) such that a sufficient remainder of aspirated detergent liquid (DL) is retained within pipettor (12) for a subsequent cleaning procedure; since pipettor (12) is no longer in contact with the detergent liquid (DL) remaining in the second container (18), the electric detection signal (S) transitions from on to off.

[0021] As mentioned above, processor (22) monitors the electric detection signal (S) generated by detector (20) during the retrieval sequences as illustrated in FIGS. 1 and 2, and can thereby determine whether the liquid retained within pipettor (12) is the deionized water (DW) or the detergent liquid (DL) and thus verify whether pipettor (12) has retrievedthe appropriate liquid for a subsequent procedure (e.g., sample analysis or cleaning) and / or verify whether pipettor (12) retrieved the appropriate liquid for a previously-performed procedure (e.g., a previous cleaning procedure in which pipettor (12) had retrieved the same liquid). More particularly, processor (22) is configured to collect the electric detection signal (S) from detector (20), and to determine a property of the liquid other than (e.g., in addition to) a level of the liquid based on the collected electric detection signal (S) and that is indicative of the type of the liquid. For example, processor (22) may be configured to collect the electric detection signal (S) at least from the aspiration of the liquid (e.g., as shown in areas ID and 2C of FIGS. 1 and 2, respectively) at least until the discharge of the liquid (e.g., as shown in areas IF and 2F of FIGS. 1 and 2, respectively). In this regard, processor (22) may be configured to determine that the liquid has a dielectric value below a liquid identification threshold based on the collected electric detection signal (S) being continuously on between the aspiration of the liquid and the discharge of the liquid; and / or may be configured to determine that the liquid has a dielectric value above the liquid identification threshold based on the collected electric detection signal (S) switching from on to off (and / or from subsequently switching from off to on) between the aspiration of the liquid and the discharge of the liquid. Thus, processor (22) may be configured to identify the liquid as either deionized water (DW) or detergent liquid (DL) based on the liquid's dielectric value being below or above the liquid identification threshold, respectively, to verify whether pipettor (12) has retrieved the appropriate liquid for the subsequent procedure. In cases where processor (22) determines that pipettor (12) has retrieved an inappropriate liquid for the subsequent procedure, processor (22) may be configured to communicate an error alert to a human operator of analyzer (10), such as via a visual display.

[0022] Referring now to FIGS. 3-4, analyzer (10) further includes a wash tower (30) for periodically cleaning at least a portion of pipettor (12), such as distal tip (14). Wash tower (30) of the present example includes a container (32) defining an interior (34) that is configured to selectively receive at least a portion of pipettor (12), and that is further configured to collect wash fluid (WF), such as deionized water, and detergent liquid (DL)from a cleaning procedure. In this regard, interior (34) of container (32) is configured to collect wash fluid (WF) that is sprayed or otherwise applied to outside surface (19) of pipettor (12) along at least the distal portion of pipettor (12), when the distal portion of pipettor (12) is inserted into interior (34) of container (32); and to collect wash fluid (WF) that is pumped through a proximal (e g., top) portion of pipettor (12) onto the inside surface of pipettor (12) along at least the distal portion of pipettor (12), such that the wash fluid (WF) and any detergent liquid (DL) retained within pipettor (12) are discharged out of distal tip (14) into interior (34) of container (32). In this manner, the wash fluid (WF) may cleanse any remnant of a prior fluid to which pipettor (12) was exposed, such as a prior patient sample, from pipettor (12) before pipettor (12) is used for a subsequent aspirating and / or dispensing procedure. For example, the wash fluid (WF) may effectively remove any remnant of a prior patient sample or reagent from pipettor (12), and the mixture of wash fluid (WF), detergent liquid (DL), and sample and / or reagent removed from pipettor (12) may be collected within interior (34) of container (32) and directed toward a bottom drain (36) of container (32) as waste fluid for removal from wash tower (30).[00023J Container (32) may have an electrode (not shown) either integrally formed or otherwise associated therewith, and detector (20) may be configured to detect an electrostatic capacitance between such an electrode and pipettor (12) in a manner similar to that described above. In some cases, container (32) may be constructed from an electrically conductive material, such as an electrically conductive metal, such that container (32) may itself serve as such an electrode. It will be appreciated that the responsiveness of detector (20) may be dependent on the particular capacitance and / or conductivity of the detergent liquid (DL) discharged from pipettor (12) into container (32), such that the responsiveness of detector (20) may vary based on the detergent liquid (DL) discharged from pipettor (12) into container (32). For example, detector (20) may be less responsive for a low concentration electrically conductive detergent liquid (LDL), which may be quickly diluted by the wash fluid (WF), and may be more responsive for a high concentration electrically conductive detergent liquid (HDL), which may be slowly diluted by the wash fluid (WF). As described in greater detail below, processor (22) is configuredto determine the concentration of detergent liquid discharged from pipettor (12) based at least in part on such differences in responsiveness.

[0024] In this regard, processor (22) is configured to monitor the electric detection signal (S) generated by detector (20) during execution of a washing sequence that includes intermittently rinsing pipettor (12) for determining the concentration of detergent liquid discharged from pipettor (12) into container (32). Such a washing sequence may be performed following performance of the above liquid retrieval sequence, such as in cases where processor (22) has verified that pipettor (12) has retrieved the detergent liquid (DL). FIG. 3 illustrates an example of this sequence when pipettor (12) discharges low concentration detergent liquid (LDL) into container (32), while FIG. 4 illustrates an example of this sequence when pipettor (12) discharges high concentration detergent liquid (HDL) into container (32).

[0025] Referring now primarily to FIG. 3, an example of a washing sequence in which pipettor (12) discharges low concentration detergent liquid (LDL) into container (32) is shown. As shown in area 3A of FIG. 3, pipettor (12) is initially lowered into container (32); since pipettor (12) has not yet discharged the low concentration detergent liquid (LDL) into container (32) and is thus electrically isolated from the electrode of container (32) at this stage, the electric detection signal (S) is off. As shown in area 3B of FIG. 3, the lowering of pipettor (12) continues until distal tip (14) of pipettor (12) reaches a predetermined discharge position, at which the wash fluid (WF) is sprayed or otherwise applied to outside surface (19) of pipettor (12) along at least the distal portion of pipettor (12) to thereby rinse pipettor (12), and at which additional wash fluid (WF) is pumped through a proximal (e.g., top) portion of pipettor (12) onto the inside surface of pipettor (12) along at least the distal portion of pipettor (12), such that the low concentration detergent liquid (LDL) is discharged out of distal tip (14) into interior (34) of container (32); since the combination of wash fluid (WF) and low concentration detergent liquid (LDL) is in contact with both pipettor (12) and the electrode of container (32), the electric detection signal (S) may transition from off to on. In some instances, the illustrated low concentration detergent liquid (LDL) may be replaced or supplemented by sample liquid.

[0026] As shown in area 3C of FIG. 3, after a first predetermined interval, the spraying of wash fluid (WF) onto outside surface (19) is ceased while a stream of liquid including the low concentration detergent liquid (LDL) and wash fluid-diluted detergent liquid (DDL) is discharged out of distal tip (14) into interior (34) of container (32) toward drain (36) (e.g., due to continued pumping of wash fluid (WF) through pipettor (12) and / or due to gravity after ceasing pumping of wash fluid (WF) through pipettor (12)); since the low concentration detergent liquid (LDL) is no longer in contact with the electrode of container (32) (e.g., via the sprayed wash fluid (WF)), and / or due to the wash fluid-diluted detergent liquid (DDL) having a substantially low capacitance and / or low conductivity (e.g., at least by comparison to the low concentration detergent liquid (LDL)), the electric detection signal (S) may transition from on to off. As shown in area 3D of FIG. 3, after a second predetermined interval, the spraying of wash fluid (WF) onto outside surface (19) is resumed while the pumping of the wash fluid (WF) through pipettor (12) continues, such that the wash fluid-diluted detergent liquid (DDL) continues to be discharged out of distal tip (14) into interior (34) of container (32); due to the wash fluid-diluted detergent liquid (DDL) having a substantially low capacitance and / or low conductivity (e.g., at least by comparison to the low concentration detergent liquid (LDL)), the electric detection signal (S) remains off.

[0027] As shown in area 3E of FIG. 3, after a third predetermined interval, the spraying of wash fluid (WF) onto outside surface (19) is ceased while the wash fluid-diluted detergent liquid (DDL) continues to be discharged out of distal tip (14) into interior (34) of container (32) toward drain (36) (e.g., due to continued pumping of wash fluid (WF) through pipettor (12) and / or due to gravity after ceasing pumping of wash fluid (WF) through pipettor (12)); since the low concentration detergent liquid (LDL) is no longer in contact with the electrode of container (32), and / or due to the wash fluid-diluted detergent liquid (DDL) having a substantially low capacitance and / or low conductivity (e.g., at least by comparison to the low concentration detergent liquid (LDL)), the electric detection signal (S) remains off. As shown in area 3F of FIG. 3, after a fourth predetermined interval, the spraying of wash fluid (WF) onto outside surface (19) is resumed while the pumpingof the wash fluid (WF) through pipettor (12) continues, such that the wash fluid-diluted detergent liquid (DDL) continues to be discharged out of distal tip (14) into interior (34) of container (32); due to the wash fluid-diluted detergent liquid (DDL) having a substantially low capacitance and / or low conductivity (e.g., at least by comparison to the low concentration detergent liquid (LDL)), the electric detection signal (S) remains off.

[0028] As shown in area 3G of FIG. 3, after a fifth predetermined interval, the spraying of wash fluid (WF) onto outside surface (19) is ceased while the wash fluid-diluted detergent liquid (DDL) continues to be discharged out of distal tip (14) into interior (34) of container (32) toward drain (36) (e.g., due to continued pumping of wash fluid (WF) through pipettor (12) and / or due to gravity after ceasing pumping of wash fluid (WF) through pipettor (12)); since the low concentration detergent liquid (LDL) is no longer in contact with the electrode of container (32), and / or due to the wash fluid-diluted detergent liquid (DDL) having a substantially low capacitance and / or low conductivity (e.g., at least by comparison to the low concentration detergent liquid (LDL)), the electric detection signal (S) remains off. As shown in area 3H of FIG. 3, after a sixth predetermined interval, the spraying of wash fluid (WF) onto outside surface (19) is resumed while the pumping of the wash fluid (WF) through pipettor (12) continues, such that the wash fluid-diluted detergent liquid (DDL) continues to be discharged out of distal tip (14) into interior (34) of container (32); due to the wash fluid-diluted detergent liquid (DDL) having a substantially low capacitance and / or low conductivity (e.g., at least by comparison to the low concentration detergent liquid (LDL)), the electric detection signal (S) remains off. In some cases, the rinsing of pipettor (12) (e.g., the spraying of wash fluid (WF) onto outside surface (19)) may be performed a predetermined number of times (e.g., four times) during the washing sequence.

[0029] Referring now primarily to FIG. 4, an example of a washing sequence in which pipettor (12) discharges high concentration detergent liquid (HDL) into container (32) is shown. As shown in area 4A of FIG. 4, pipettor (12) is initially lowered into container (32); since pipettor (12) has not yet discharged the high concentration detergent liquid (HDL) into container (32) and is thus electrically isolated from the electrode of container(32) at this stage, the electric detection signal (S) is off. As shown in area 4B of FIG. 4, the lowering of pipettor (12) continues until distal tip (14) of pipettor (12) reaches the predetermined discharge position, at which the wash fluid (WF) is sprayed or otherwise applied to outside surface (19) of pipettor (12) along at least the distal portion of pipettor (12) to thereby rinse pipettor (12), and at which additional wash fluid (WF) is pumped through a proximal (e.g., top) portion of pipettor (12) onto the inside surface of pipettor (12) along at least the distal portion of pipettor (12), such that the high concentration detergent liquid (HDL) is discharged out of distal tip (14) into interior (34) of container (32); since the combination of wash fluid (WF) and high concentration detergent liquid (HDL) is in contact with both pipettor (12) and the electrode of container (32) and has a sufficiently high dielectric value, the electric detection signal (S) transitions from off to on.

[0030] As shown in area 4C of FIG. 4, after the first predetermined interval, the spraying of wash fluid (WF) onto outside surface (19) is ceased while the high concentration detergent liquid (HDL) is discharged out of distal tip (14) into interior (34) of container (32) toward drain (36) (e.g., due to continued pumping of wash fluid (WF) through pipettor (12) and / or due to gravity after ceasing pumping of wash fluid (WF) through pipettor (12)); since the high concentration detergent liquid (HDL) is no longer in contact with the electrode of container (32) (e.g., via the sprayed wash fluid (WF)), the electric detection signal (S) may transition from on to off. As shown in area 4D of FIG. 4, after the second predetermined interval, the spraying of wash fluid (WF) onto outside surface (19) is resumed while the pumping of the wash fluid (WF) through pipettor (12) continues, such that a stream of liquid including the high concentration detergent liquid (HDL) and wash fluid-diluted detergent liquid (DDL) is discharged out of distal tip (14) into interior (34) of container (32); since the combination of wash fluid (WF), high concentration detergent liquid (HDL), and wash fluid-diluted detergent liquid (DDL) is in contact with both pipettor (12) and the electrode of container (32) and has a sufficiently high dielectric value, the electric detection signal (S) transitions from off to on.

[0031] As shown in area 4E of FIG. 4, after the third predetermined interval, the spraying of wash fluid (WF) onto outside surface (19) is ceased while the stream of liquid includingthe high concentration detergent liquid (HDL) and wash fluid-diluted detergent liquid (DDL) continues to be discharged out of distal tip (14) into interior (34) of container (32) toward drain (36) (e.g., due to continued pumping of wash fluid (WF) through pipettor (12) and / or due to gravity after ceasing pumping of wash fluid (WF) through pipettor (12)); since the high concentration detergent liquid (HDL) is no longer in contact with the electrode of container (32), the electric detection signal (S) may transition from on to off. As shown in area 4F of FIG. 4, after the fourth predetermined interval, the spraying of wash fluid (WF) onto outside surface (19) is resumed while the pumping of the wash fluid (WF) through pipettor (12) continues, such that the stream of liquid including the high concentration detergent liquid (HDL) and wash fluid-diluted detergent liquid (DDL) continues to be discharged out of distal tip (14) into interior (34) of container (32); since the combination of wash fluid (WF), high concentration detergent liquid (HDL), and wash fluid-diluted detergent liquid (DDL) is in contact with both pipettor (12) and the electrode of container (32) and has a sufficiently high dielectric value, the electric detection signal (S) transitions from off to on.[00032J As shown in area 4G of FIG. 4, after the fifth predetermined interval, the spraying of wash fluid (WF) onto outside surface (19) is ceased while the wash fluid-diluted detergent liquid (DDL) continues to be discharged out of distal tip (14) into interior (34) of container (32) toward drain (36) (e.g., due to continued pumping of wash fluid (WF) through pipettor (12) and / or due to gravity after ceasing pumping of wash fluid (WF) through pipettor (12)); since the high concentration detergent liquid (HDL) is no longer in contact with the electrode of container (32), and / or due to the wash fluid-diluted detergent liquid (DDL) having a substantially low capacitance and / or low conductivity (e.g., at least by comparison to the high concentration detergent liquid (HDL)), the electric detection signal (S) transitions from on to off. As shown in area 4H of FIG. 4, after the sixth predetermined interval, the spraying of wash fluid (WF) onto outside surface (19) is resumed while the pumping of the wash fluid (WF) through pipettor (12) continues, such that the wash fluid-diluted detergent liquid (DDL) continues to be discharged out of distal tip (14) into interior (34) of container (32); due to the wash fluid-diluted detergent liquid(DDL) having a substantially low capacitance and / or low conductivity (e.g., at least by comparison to the high concentration detergent liquid (HDL)), the electric detection signal (S) remains off. In some cases, the rinsing of pipettor (12) (e.g., the spraying of wash fluid (WF) onto outside surface (19)) may be performed the predetermined number of times during the washing sequence.

[0033] As mentioned above, processor (22) monitors the electric detection signal (S) generated by detector (20) during the washing sequences as illustrated in FIGS. 3 and 4, and can thereby determine the concentration of detergent liquid discharged from pipettor (12) into container (32) and thus verify whether concentration of the detergent liquid is sufficiently high for effective cleaning of pipettor (12). More particularly, processor (22) is configured to collect the electric detection signal (S) from detector (20), and to determine a property of the detergent liquid other than a level of the detergent liquid based on the collected electric detection signal (S) and that is indicative of the concentration of the detergent liquid. For example, processor (22) may be configured to collect the electric detection signal (S) at least from the moving of pipettor (12) to the predetermined position in wash tower (30) (e.g., as shown in areas 3B and 4B of FIGS. 3 and 4, respectively) at least until completion of rinsing pipettor (12) the predetermined number of times (e.g., as shown in areas 3H and 4H of FIGS. 3 and 4, respectively). In this regard, processor (22) may be configured to determine that the concentration of the detergent liquid is above a dilution threshold based on the electric detection signal (S) having a number of on-states greater than or equal to a predetermined number of on-states (e.g., two on-states); and / or may be configured to determine that the concentration of the detergent liquid is below the dilution threshold based on the electric detection signal (S) having a number of on-states less than the predetermined number of on-states. In cases where processor (22) determines that the detergent liquid is below the dilution threshold, processor (22) may be configured to communicate an error alert to a human operator of analyzer (10), such as via the visual display.

[0034] Referring now to FIG. 5, an example of a method of use (100) with a capacitance based liquid level detector, such as detector (20), includes a step (101) at which a level ofliquid stored in a container, such as any of containers (16, 18, 32), is detected by detector (20). Method (100) proceeds from step (101) to step (102), at which a predetermined volume of the liquid is aspirated into a probe associated with detector (20), such as pipettor (12). Method (100) proceeds from step (102) to step (103), at which an electric detection signal (S) of detector (20) is collected, such as via processor (22). In the example shown, method (100) also proceeds from step (102) to step (104), at which pipettor (12) is moved away from the liquid. Method (100) proceeds from step (104) to step (105), at which a portion of the liquid is discharged out of pipettor (12). As shown, step (103) is performed continuously from step (102) to step (105). Method (100) proceeds from step (103) and / or step (105) to step (106), at which another property of the liquid in addition to a level of the liquid is determined based on the electric detection signal (S) collected at step (103), such as via processor (22). For example, step (106) may include determining a type of the liquid based on the collected electric detection signal (S), such as via processor (22). In this regard, step (106) may include determining that the liquid has a dielectric value below a liquid identification threshold based on the collected electric detection signal (S) continuously being on, such as via processor (22); and / or determining that the liquid has a dielectric value above the liquid identification threshold based on the collected electric detection signal (S) switching from on to off, such as via processor (22). In some versions, step (106) may be performed during step (104) and / or step (105). Step (106) may include identifying the liquid as either deionized water or detergent based on the liquid's dielectric value being below or above the liquid identification threshold, respectively. In some cases, method (100) may terminate at step (106).

[0035] In the example shown, method (100) proceeds from step (106) to step (107), at which pipettor (12) is moved with the aspirated liquid therein to a predetermined position in a washing tower, such as wash tower (30). In some cases, method (100) may only proceed from step (106) to step (107) in response to a determination at step (106) that the liquid has a dielectric value above the liquid identification threshold. In some other cases, steps (101, 102, 103, 104, 105, 106) may be omitted from method (100), such that method may commence with step (107).

[0036] Method (100) proceeds from step (107) to step (108), at which pipettor (12) is rinsed in wash tower (30) a predetermined number of times. In the example shown, method (100) also proceeds from step (106) to step (109), at which an electric detection signal (S) of detector (20) is collected, such as via processor (22). As shown, step (109) is performed continuously from step (107) to step (108). Method (100) proceeds from step (108) and / or step (109) to step (110), at which another property of the liquid other than a level of the liquid is determined based on the electric detection signal (S) collected at step (109), such as via processor (22). For example, step (110) may include determining a concentration of the liquid based on the collected electric detection signal (S), such as via processor (22). In this regard, step (110) may include determining that the concentration of the liquid in the probe is above a dilution threshold based on the collected electric detection signal (S) having a number of on-states greater than or equal to a predetermined number of on-states, such as via processor (22); and / or determining that the concentration of the liquid in the probe is below the dilution threshold based on the number of on-states of the collected electric detection signal (S) being less than the predetermined number of on-states, such as via processor (22). In some versions, step (110) may be performed during step (107) and / or step (108).

[0037] Referring now to FIG. 6, another example of a method of use (200) with a capacitance based liquid level detector, such as detector (20), includes a step (201 ) at which an electric detection signal (S) of detector (20) is collected, such as via processor (22), during a period extending from a first time to a second time. In this regard, the electric detection signal (S) may have a first state (e.g., on) and a second state (e.g., off), and detector (20) may indicate the presence of liquid in contact with a surface of pipettor (12), such as outside surface (19), when the electric detection signal (S) is in the first state. Method (200) also includes a step (202) at which a probe associated with detector (20), such as pipettor (12), is moved in a first direction (e.g., downwardly) to thereby move pipettor (12) into a container, such as any of containers (16, 18, 32), at the first time. For example, at the first time, pipettor (12) may be being moved in the first direction, outside surface (19) of pipettor (12) may not be in contact with the liquid, and the electric detectionsignal (S) may be in the second state. Method (200) proceeds from step (202) to step (203), at which contact is established between a liquid and outside surface (19) of pipettor (12) in container (16, 18, 32), during the period extending from the first time to the second time. Method (200) proceeds from step (203) to step (204), at which liquid is aspirated into pipettor (12), during the period extending from the first time to the second time. Method (200) proceeds from step (204) to step (205), at which liquid is discharged from pipettor (12), during the period extending from the first time to the second time. Method (200) proceeds from step (205) to step (206), at which pipettor (12) is withdrawn from container (16, 18, 32) by moving pipettor (12) in a second direction opposite the first direction (e.g., upwardly), at the second time. For example, at the second time, pipettor (12) may be being moved in the second direction, outside surface (19) of pipettor (12) may not be contact with the liquid, and the electric detection signal (S) may be in the second state.

[0038] In the example shown, method (200) proceeds from step (201) to step (207), at which a property of the liquid other than liquid level is determined, such as via processor (22), based on a number of times the electric detection signal (S) switches between the first state and the second state during the period extending from the first time to the second time. For example, step (207) may include processor (22) selecting a liquid type from a set of liquid types based on the number of times the electric detection signal (S) switches between the first state and the second state during the period extending from the first time to the second time. In this regard, step (207) may include determining, such as via processor (22), that the liquid has a dielectric value below a liquid identification threshold based on the electric detection signal (S) switching between the first state and the second state twice during the period extending from the first time to the second time, once from the first state to the second state and once from the second state to the first state; and / or determining, such as via processor (22), that the liquid has a dielectric value above the liquid identification threshold based on the electric detection signal (S) switching between the first state and the second state four times during the period extending from the first time to the second time, twice from the first state to the second state and twice from the second state to the first state. In some cases, the set of liquid types includes deionizedwater and detergent, and step (207) includes selecting the liquid type for the liquid as either deionized water or detergent based on whether the liquid’s dielectric value is above or below the liquid identification threshold. In some cases, method (200) may terminate at step (207).

[0039] In the example shown, in response to a determination at step (207) that the liquid’s dielectric value is above the liquid identification threshold, method (200) proceeds from step (206) and step (207) to step (208), at which pipettor (12) is moved to a washing tower, such as wash tower (30). In some cases, steps (201, 202, 203, 204, 205, 206, 207) may be omitted from method (200), such that method may commence with step (208).

[0040] Method (200) proceeds from step (208) to step (209), at which pipettor (12) is rinsed in wash tower (30) one or more times. In the example shown, method (100) also proceeds from step (208) to step (210), at which the electric detection signal (S) of detector (20) is collected, such as via processor (22), during a period extending from a third time to a fourth time. For example, at the third time, pipettor (12) may have already been moved to wash tower (30) and is being moved in the first direction, step (209) has not yet begun, and the electric detection signal (S) may be in the second state; and / or at the fourth time, pipettor (12) may be discharging the liquid and has been rinsed in wash tower (30) at least one time, and the electric detection signal (S) is in the first state. Method (200) proceeds from step (209) and / or step (210) to step (211), at which a second property of the liquid other than the liquid level is determined based on a number of times the electric detection signal (S) switches between the first state and the second state during the period extending from the third time to the fourth time, such as via processor (22). For example, the second property of the liquid other than the liquid level may be concentration of the liquid. In this regard, step (211) may include determining that the concentration of the liquid is above a dilution threshold based on the electric detection signal (S) switching between the first state and the second state more than a predetermined number of times during the period extending from the third time to the fourth time, such as via processor (22); and / or determining that the concentration of the liquid is below the dilution threshold based on the electric detection signal (S) switching between the first state and the second state lessthan the predetermined number of times during the period extending from the third time to the fourth time, such as via processor (22). In some versions, step (211) may be performed during step (209) and / or step (210).

[0041] To further illustrate potential ways in which the technology described herein may be applied, the following examples are provided as showing systems and methods which may be implemented based on this disclosure.

[0042] Example 1

[0043] A method of use with a capacitance based detector, comprising the steps of: (a) aspirating a predetermined volume of liquid from a container into a probe associated with the detector; (b) collecting an electric detection signal of the detector; and (c) determining a property of the liquid other than a level of the liquid in the container based on the collected electric detection signal.

[0044] Example 2

[0045] The method according to Example 1, further comprising: (a) after aspirating the liquid, moving the probe away from the liquid; and (b) discharging the liquid out of the probe; wherein the step of collecting the electric detection signal comprises collecting the electric detection signal from the step of aspirating the liquid to the step of discharging the liquid, and wherein determining another property of the liquid comprises determining a type of the liquid based on the collected electric detection signal.

[0046] Example 3

[0047] The method according to Example 2, wherein during the step of moving the probe away from the liquid to the step of discharging the liquid, the method comprises an act selected from the following set of acts: (a) based on the collected electric detection signal continuously being on, determining that the liquid has a dielectric value below a liquid identification threshold; and (b) based on the collected electric detection signal switchingfrom on to off, determining that the liquid has a dielectric value above the liquid identification threshold.

[0048] Example 4

[0049] The method according to Example 3, wherein the method comprises identifying the liquid as either deionized water or detergent based on the liquid's dielectric value being below or above the liquid identification threshold, respectively.

[0050] Example 5

[0051] The method according to any of Examples 1 through 4, further comprising: (a) moving the probe with the aspirated liquid therein to a predetermined position in a washing tower; and (b) rinsing the probe in the washing tower a predetermined number of times; wherein the step of collecting the electric detection signal comprises collecting the electric detection signal from the step of moving the probe to completion of the step of rinsing the probe the predetermined number of times, and wherein determining another property of the liquid comprises determining a concentration of the liquid based on the collected electric detection signal.

[0052] Example 6

[0053] The method according to Example 5, wherein the method comprises an act selected from the following set of acts: (a) based on the electric detection signal having a number of on-states greater than or equal to a predetermined number of on-states, determining that the concentration of the liquid in the probe is above a dilution threshold; or (b) based on the number of on-states of the electric detection signal being less than the predetermined number of on-states, determining that the concentration of the liquid in the probe is below the dilution threshold.

[0054] Example 7

[0055] The method according to any of Examples 3 through 6, wherein: (a) the method comprises determining that the liquid’s dielectric value is above the liquid identification threshold; (b) the method comprises, after determining that the liquid’s dielectric value is above the liquid identification threshold, aspirating the liquid into the probe and moving the probe to a predetermined position in a washing tower; (c) rinsing the probe in the washing tower a predetermined number of times; wherein the step of collecting the electric detection signal comprises collecting the electric detection signal from the step of moving the probe to completion of the step of rinsing the probe the predetermined number of times, and wherein the method comprises determining a concentration of the liquid based on the collected electric detection signal.

[0056] Example 8

[0057] The method according to any of Examples 1 through 7, further comprising detecting the level of the liquid in the container based on the collected electric detection signal.

[0058] Example 9

[0059] A method of using a capacitance based detector, comprising the steps of: (a) moving a probe associated with the capacitance based detector in a first direction, wherein moving the probe in the first direction moves the probe into a container; (b) withdrawing the probe from the container by moving the probe in a second direction, wherein the second direction is opposite the first direction; (c) collecting, during a period extending from a first time to a second time, an electric detection signal, wherein: (i) the electric detection signal has a first state and a second state, wherein the capacitance based detector indicates the presence of liquid in contact with an external surface of the probe when the electric detection signal is in the first state; (ii) at the first time, the probe is being moved in the first direction, the external surface of the probe is not in contact with liquid, and the electric detection signal is in the second state; and (iii) at the second time, the probe is being moved in the second direction, the external surface of the probe is not in contact with liquid, and the electric detection signal is in the second state; (d) between the first time andthe second time, establishing contact between a liquid and the external surface of the probe in the container; and (e) determining a property of the liquid other than liquid level based on a number of times the electric detection signal switches between the first state and the second state during the period extending from the first time to the second time.

[0060] Example 10

[0061] The method of Example 9, wherein the method further comprises: (a) during the period extending from the first time to the second time: (i) aspirating liquid into the probe; and (ii) discharging liquid from the probe; (b) determining a property of the liquid other than liquid level comprises selecting a liquid type from a set of liquid types based on the number of times the electric detection signal switches between the first state and the second state during the period extending from the first time to the second time.

[0062] Example 11

[0063] The method of Example 10, wherein the method comprises an act from the following set of acts: (a) based on the electric detection signal switching between the first state and the second state twice during the period extending from the first time to the second time, once from the first state to the second state and once from the second state to the first state, determining that the liquid has a dielectric value below a liquid identification threshold; and (b) based on the electric detection signal switching between the first state and the second state four times during the period extending from the first time to the second time, twice from the first state to the second state and twice from the second state to the first state, determining that the liquid has a dielectric value above the liquid identification threshold.

[0064] Example 12

[0065] The method of any of Examples 10 through 11, wherein: (a) the set of liquid types comprises deionized water and detergent; (b) selecting the liquid type from the set of liquid types based on the number of times the electric detection signal switches between the firststate and the second state during the period extending from the first time to the second time comprises selecting the liquid type for the liquid as either deionized water or detergent based on whether the liquid’s dielectric value is above or below the liquid identification threshold.

[0066] Example 13

[0067] The method of any of Examples 10 through 12, wherein: (a) the method comprises determining the liquid’s dielectric value is above the liquid identification threshold; and (b) the method further comprises: (i) after determining that the liquid’s dielectric value is above the liquid identification threshold, moving the probe to a washing tower; (ii) rinsing the probe in the washing tower one or more times; (iii) collecting the electric detection signal from a period extending from a third time to a fourth time, wherein: (A) at the third time, the probe has already been moved to the washing tower and is being moved in the first direction, the step of rinsing the probe in the washing tower one or more times has not yet begun, and the electric detection signal is in the second state; and (B) at the fourth time, the probe is discharging the liquid and has been rinsed in the washing tower at least one time, and the electric detection signal is in the first state; and (iv) determining a second property of the liquid other than the liquid level based on a number of times the electric detection signal switches between the first state and the second state during the period extending from the third time to the fourth time.

[0068] Example 14

[0069] The method of Example 13, wherein the second property of the liquid other than the liquid level is concentration of the liquid.

[0070] Example 15

[0071] The method of Example 14, wherein determining the second property of the liquid other than the liquid level based on the number of times the electric detection signal switches between the first state and the second state during the period extending from thethird time to the fourth time comprises an act selected from: (a) based on the electric detection signal switching between the first state and the second state more than a predetermined number of times during the period extending from the third time to the fourth time, determining that the concentration of the liquid is above a dilution threshold; and (b) based on the electric detection signal switching between the first state and the second state less than the predetermined number of times during the period extending from the third time to the fourth time, determining that the concentration of the liquid is below the dilution threshold.

[0072] Example 16

[0073] The method of any of Examples 9 through 15, wherein: (a) the container is a washing tower; (b) the method further comprises, during the period extending from the first time to the second time, rinsing the probe in the washing tower one or more times; and (c) the property of the liquid other than the liquid level is concentration of the liquid.

[0074] Example 17

[0075] The method of Example 16, wherein determining the property of the liquid other than the liquid level based on the number of times the electric detection signal switches between the first state and the second state during the period extending from the first time to the second time comprises an act selected from: (a) based on the electric detection signal switching between the first state and the second state more than a predetermined number of times during the period extending from the first time to the second time, determining that the concentration of the liquid is above a dilution threshold; and (b) based on the electric detection signal switching between the first state and the second state less than the predetermined number of times during the period extending from the first time to the second time, determining that the concentration of the liquid is below the dilution threshold.

[0076] Having shown and described various embodiments of the present invention, further adaptations of the methods and systems described herein may be accomplished byappropriate modifications by one of ordinary skill in the art without departing from the scope of the present invention. Several of such potential modifications have been mentioned, and others will be apparent to those skilled in the art. For instance, the examples, embodiments, geometries, materials, dimensions, ratios, steps, and the like discussed above are illustrative and are not required. Accordingly, the scope of the present invention should be considered in terms of the following claims and is understood not to be limited to the details of structure and operation shown and described in the specification and drawings.

Claims

I / We claim:

1. A method of use with a capacitance based detector, comprising the steps of:(a) aspirating a predetermined volume of liquid from a container into a probe associated with the detector;(b) collecting an electric detection signal of the detector; and(c) determining a property of the liquid other than a level of the liquid in the container based on the collected electric detection signal.

2. The method according to claim 1, further comprising:(a) after aspirating the liquid, moving the probe away from the liquid; and(b) discharging the liquid out of the probe; wherein the step of collecting the electric detection signal comprises collecting the electric detection signal from the step of aspirating the liquid to the step of discharging the liquid, and wherein determining another property of the liquid comprises determining a type of the liquid based on the collected electric detection signal.

3. The method according to claim 2, wherein during the step of moving the probe away from the liquid to the step of discharging the liquid, the method comprises an act selected from the following set of acts:(a) based on the collected electric detection signal continuously being on, determining that the liquid has a dielectric value below a liquid identification threshold; and(b) based on the collected electric detection signal switching from on to off, determining that the liquid has a dielectric value above the liquid identification threshold.

4. The method according to claim 3, wherein the method comprises identifying the liquid as either deionized water or detergent based on the liquid's dielectric value being below or above the liquid identification threshold, respectively.

5. The method according to claim 1, further comprising:(a) moving the probe with the aspirated liquid therein to a predetermined position in a washing tower; and(b) rinsing the probe in the washing tower a predetermined number of times; wherein the step of collecting the electric detection signal comprises collecting the electric detection signal from the step of moving the probe to completion of the step of rinsing the probe the predetermined number of times, and wherein determining another property of the liquid comprises determining a concentration of the liquid based on the collected electric detection signal.

6. The method according to claim 5, wherein the method comprises an act selected from the following set of acts:(a) based on the electric detection signal having a number of on-states greater than or equal to a predetermined number of on-states, determining that the concentration of the liquid in the probe is above a dilution threshold; or(b) based on the number of on-states of the electric detection signal being less than the predetermined number of on-states, determining that the concentration of the liquid in the probe is below the dilution threshold.

7. The method according to claim 3, wherein:(a) the method comprises determining that the liquid’ s dielectric value is above the liquid identification threshold;(b) the method comprises, after determining that the liquid’s dielectric value is above the liquid identification threshold, aspirating the liquid into the probe and moving the probe to a predetermined position in a washing tower;(c) rinsing the probe in the washing tower a predetermined number of times;wherein the step of collecting the electric detection signal comprises collecting the electric detection signal from the step of moving the probe to completion of the step of rinsing the probe the predetermined number of times, and wherein the method comprises determining a concentration of the liquid based on the collected electric detection signal.

8. The method according to claim 1, further comprising detecting the level of the liquid in the container based on the collected electric detection signal.

9. A method of using a capacitance based detector, comprising the steps of:(a) moving a probe associated with the capacitance based detector in a first direction, wherein moving the probe in the first direction moves the probe into a container;(b) withdrawing the probe from the container by moving the probe in a second direction, wherein the second direction is opposite the first direction;(c) collecting, during a period extending from a first time to a second time, an electric detection signal, wherein:(i) the electric detection signal has a first state and a second state, wherein the capacitance based detector indicates the presence of liquid in contact with an external surface of the probe when the electric detection signal is in the first state;(ii) at the first time, the probe is being moved in the first direction, the external surface of the probe is not in contact with liquid, and the electric detection signal is in the second state; and(iii) at the second time, the probe is being moved in the second direction, the external surface of the probe is not in contact with liquid, and the electric detection signal is in the second state;(d) between the first time and the second time, establishing contact between a liquid and the external surface of the probe in the container; and(e) determining a property of the liquid other than liquid level based on a number of times the electric detection signal switches between the first state and the second state during the period extending from the first time to the second time.

10. The method of claim 9, wherein the method further comprises:(a) during the period extending from the first time to the second time:(i) aspirating liquid into the probe; and(ii) discharging liquid from the probe;(b) determining a property of the liquid other than liquid level comprises selecting a liquid type from a set of liquid types based on the number of times the electric detection signal switches between the first state and the second state during the period extending from the first time to the second time.

11. The method of claim 10, wherein the method comprises an act from the following set of acts:(a) based on the electric detection signal switching between the first state and the second state twice during the period extending from the first time to the second time, once from the first state to the second state and once from the second state to the first state, determining that the liquid has a dielectric value below a liquid identification threshold; and(b) based on the electric detection signal switching between the first state and the second state four times during the period extending from the first time to the second time, twice from the first state to the second state and twice from the second state to the first state, determining that the liquid has a dielectric value above the liquid identification threshold.

12. The method of claim 10, wherein:(a) the set of liquid types comprises deionized water and detergent;(b) selecting the liquid type from the set of liquid types based on the number of times the electric detection signal switches between the first state and the second state during the period extending from the first time to the second time comprises selecting the liquid type for the liquid as either deionized water or detergent based on whether the liquid’s dielectric value is above or below the liquid identification threshold.

13. The method of claim 10, wherein:(a) the method comprises determining the liquid’s dielectric value is above the liquid identification threshold; and(b) the method further comprises:(i) after determining that the liquid’s dielectric value is above the liquid identification threshold, moving the probe to a washing tower;(ii) rinsing the probe in the washing tower one or more times;(iii) collecting the electric detection signal from a period extending from a third time to a fourth time, wherein:(A) at the third time, the probe has already been moved to the washing tower and is being moved in the first direction, the step of rinsing the probe in the washing tower one or more times has not yet begun, and the electric detection signal is in the second state; and(B) at the fourth time, the probe is discharging the liquid and has been rinsed in the washing tower at least one time, and the electric detection signal is in the first state; and(iv) determining a second property of the liquid other than the liquid level based on a number of times the electric detection signal switches between the first state and the second state during the period extending from the third time to the fourth time.

14. The method of claim 13, wherein the second property of the liquid other than the liquid level is concentration of the liquid.

15. The method of claim 14, wherein determining the second property of the liquid other than the liquid level based on the number of times the electric detection signal switches between the first state and the second state during the period extending from the third time to the fourth time comprises an act selected from:(a) based on the electric detection signal switching between the first state and the second state more than a predetermined number of times during the period extending from the third time to the fourth time, determining that the concentration of the liquid is above a dilution threshold; and(b) based on the electric detection signal switching between the first state and the second state less than the predetermined number of times during the period extending from the third time to the fourth time, determining that the concentration of the liquid is below the dilution threshold.

16. The method of claim 9, wherein:(a) the container is a washing tower;(b) the method further comprises, during the period extending from the first time to the second time, rinsing the probe in the washing tower one or more times; and(c) the property of the liquid other than the liquid level is concentration of the liquid.

17. The method of claim 16, wherein determining the property of the liquid other than the liquid level based on the number of times the electric detection signal switches between the first state and the second state during the period extending from the first time to the second time comprises an act selected from:(a) based on the electric detection signal switching between the first state and the second state more than a predetermined number of times during theperiod extending from the first time to the second time, determining that the concentration of the liquid is above a dilution threshold; and(b) based on the electric detection signal switching between the first state and the second state less than the predetermined number of times during the period extending from the first time to the second time, determining that the concentration of the liquid is below the dilution threshold.

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