CA1306779C - Liquid level sensor, used in an automatic station for preparing immunologic dosages - Google Patents
Liquid level sensor, used in an automatic station for preparing immunologic dosagesInfo
- Publication number
- CA1306779C CA1306779C CA000523105A CA523105A CA1306779C CA 1306779 C CA1306779 C CA 1306779C CA 000523105 A CA000523105 A CA 000523105A CA 523105 A CA523105 A CA 523105A CA 1306779 C CA1306779 C CA 1306779C
- Authority
- CA
- Canada
- Prior art keywords
- sensor
- pressure
- output signal
- liquid level
- conductive fluid
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N35/00—Automatic analysis not limited to methods or materials provided for in any single one of groups G01N1/00 - G01N33/00; Handling materials therefor
- G01N35/10—Devices for transferring samples or any liquids to, in, or from, the analysis apparatus, e.g. suction devices, injection devices
- G01N35/1081—Devices for transferring samples or any liquids to, in, or from, the analysis apparatus, e.g. suction devices, injection devices characterised by the means for relatively moving the transfer device and the containers in an horizontal plane
- G01N35/109—Devices for transferring samples or any liquids to, in, or from, the analysis apparatus, e.g. suction devices, injection devices characterised by the means for relatively moving the transfer device and the containers in an horizontal plane with two horizontal degrees of freedom
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01F—MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
- G01F23/00—Indicating or measuring liquid level or level of fluent solid material, e.g. indicating in terms of volume or indicating by means of an alarm
- G01F23/22—Indicating or measuring liquid level or level of fluent solid material, e.g. indicating in terms of volume or indicating by means of an alarm by measuring physical variables, other than linear dimensions, pressure or weight, dependent on the level to be measured, e.g. by difference of heat transfer of steam or water
- G01F23/24—Indicating or measuring liquid level or level of fluent solid material, e.g. indicating in terms of volume or indicating by means of an alarm by measuring physical variables, other than linear dimensions, pressure or weight, dependent on the level to be measured, e.g. by difference of heat transfer of steam or water by measuring variations of resistance of resistors due to contact with conductor fluid
- G01F23/241—Indicating or measuring liquid level or level of fluent solid material, e.g. indicating in terms of volume or indicating by means of an alarm by measuring physical variables, other than linear dimensions, pressure or weight, dependent on the level to be measured, e.g. by difference of heat transfer of steam or water by measuring variations of resistance of resistors due to contact with conductor fluid for discrete levels
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N35/00—Automatic analysis not limited to methods or materials provided for in any single one of groups G01N1/00 - G01N33/00; Handling materials therefor
- G01N35/10—Devices for transferring samples or any liquids to, in, or from, the analysis apparatus, e.g. suction devices, injection devices
- G01N35/1009—Characterised by arrangements for controlling the aspiration or dispense of liquids
- G01N2035/1025—Fluid level sensing
Abstract
Abstract A liquid level sensor, suitable for use as an auxiliary device in an automatic station for preparing immunologic dosages, consists of a U-pipe containing water, one end of said U-pipe being provided with a resistivity sensor, the other end of said U-pipe being connected to the terminal of a liquid dispensing or suction system of the automatic station such that a very small pressure difference within the system results in a water level variation in the branches of the U-pipe and in the relevant activation (or deactivation) of the resistivity sensor.
Description
~ G;7~
Li uid level sensor used in an automatic station or q .
preparing immunologic dosages The present invention relates to auxiliary devices for automatic equipment, particularly liquid level sensors~
More particularly, the invention relates to a liquid level sensor suitable as an auxiliary device in an automatic station for preparing immunologic dosages~
The determination for diagnostic purposes of substances present in the blood at very low concentrations, such as hormones, drugs, proteins etc., is today possible by the use of immunologic dosage technologies (RIA, EIA, etc.,~
characterized by a very high sensitivity. The preparation of such dosages which require incubation of several sub-stances (e.g. unknown antigen, marked antigen, specific antibody) in a single test tube~ is carried out in several phases. One phase is the suction, from several containers or test tubes, of liquids containing the reagents, and subsequently the dispensing of these liquicls into the test tubes where the reactions are to take place. These operations are generally performed manually by an operator using dispensing pipettes.
In recent years, within the scope of an automated process including all the phases of immunologic dosage preparation, computerized stations for the dispensing of dosage liquids have been developed. A typical automatic station consists of a computer controlling the operation ~ ' 3C~
of:
(a) a plotter for positioning X, Y, Z of a dispensing probe on an operation surface carrying dosage trays;
(b) a diluter, connected to the probe, for suctioning and dispensing the liquids.
The diluter normally consists of one or more syringes, connected by means of flexible tubesl to the probe of the plotter. The suction and dispensing operations are carried out by moving the syringe piston up or down. The plotter probe is usually known as the z-axis, and has no fixed needle~ but uses tips which at intervals are taken from a suitable tray and automatically changed after each dispen-sing operation, so as to avoid any possible contamination.
Usually, during operation of the preparing station, the tip collects several times from the same test tube (or container) predetermined quantities of the liquid to be dispensed. Therefore, taking into account that the liquid quantity in the test tube decreases according to the number of withdrawals, it is necessary that the system should know, beore each suction, the quantity of liquid available as compared with the required quantity. That is, it is necessary to know, before withdrawing, the vol-ume of liquid contained in the test tube. However, since the geometLy of the liquid is known, it is sufficient ko know one parameter only: the liquid level in the test tube. To obtain this inormation, it has been necessary to create a system which, during the lowering o the z-axis into the test tube, is able to:
- rapidly block the movement as soon as the tip of the z-axis touches the free surface of the liquid, - signal to the computer the level reached by the tip, in respect to a reference base tæ-home).
This system permits the computer to know the level, and therefore the volume, of the liquid contained in the test tube. If the quantity of liquid is sufficient to `' ~ . , .
, ~3~
satisfy the re~uest, the computer can at this point lower the tip, with reference to the free surface of the liquid, to a depth corresponding to the volume of liquid to be withdrawn, thus making it unnecessary to lower the tip more than necessary. The operation can be even more refined, by performing, in subsequent steps, small im-mersions of the tip with alternate suctioning of small volumes of liquid until the total volume to be withdrawn has been reached. In this manner only a small portion of the tip is maintained immersed in the liquid.
The sensors more commonly used to detect liquid levels are the capacity and resistivity types. Capacity sensors detect the difference in the dielectric constant, and therefore the capacity, when there are varia~ions in the media in which they are immersed. The resistivity sensors make use of the conductivity of the liquid in which they are immersed, which short-circuits the two electric con-tacts. Unfortunately the direct application of these sensors for the system in question would be impossible, for the following reasons:
1) - The different liquids to be suctionedr in order to prepare the dosages, have electric properties which differ; for instance, not all the liquids have good conductivity. Therefore, there is low reliability ~5 of the signals given by the sensors.
Li uid level sensor used in an automatic station or q .
preparing immunologic dosages The present invention relates to auxiliary devices for automatic equipment, particularly liquid level sensors~
More particularly, the invention relates to a liquid level sensor suitable as an auxiliary device in an automatic station for preparing immunologic dosages~
The determination for diagnostic purposes of substances present in the blood at very low concentrations, such as hormones, drugs, proteins etc., is today possible by the use of immunologic dosage technologies (RIA, EIA, etc.,~
characterized by a very high sensitivity. The preparation of such dosages which require incubation of several sub-stances (e.g. unknown antigen, marked antigen, specific antibody) in a single test tube~ is carried out in several phases. One phase is the suction, from several containers or test tubes, of liquids containing the reagents, and subsequently the dispensing of these liquicls into the test tubes where the reactions are to take place. These operations are generally performed manually by an operator using dispensing pipettes.
In recent years, within the scope of an automated process including all the phases of immunologic dosage preparation, computerized stations for the dispensing of dosage liquids have been developed. A typical automatic station consists of a computer controlling the operation ~ ' 3C~
of:
(a) a plotter for positioning X, Y, Z of a dispensing probe on an operation surface carrying dosage trays;
(b) a diluter, connected to the probe, for suctioning and dispensing the liquids.
The diluter normally consists of one or more syringes, connected by means of flexible tubesl to the probe of the plotter. The suction and dispensing operations are carried out by moving the syringe piston up or down. The plotter probe is usually known as the z-axis, and has no fixed needle~ but uses tips which at intervals are taken from a suitable tray and automatically changed after each dispen-sing operation, so as to avoid any possible contamination.
Usually, during operation of the preparing station, the tip collects several times from the same test tube (or container) predetermined quantities of the liquid to be dispensed. Therefore, taking into account that the liquid quantity in the test tube decreases according to the number of withdrawals, it is necessary that the system should know, beore each suction, the quantity of liquid available as compared with the required quantity. That is, it is necessary to know, before withdrawing, the vol-ume of liquid contained in the test tube. However, since the geometLy of the liquid is known, it is sufficient ko know one parameter only: the liquid level in the test tube. To obtain this inormation, it has been necessary to create a system which, during the lowering o the z-axis into the test tube, is able to:
- rapidly block the movement as soon as the tip of the z-axis touches the free surface of the liquid, - signal to the computer the level reached by the tip, in respect to a reference base tæ-home).
This system permits the computer to know the level, and therefore the volume, of the liquid contained in the test tube. If the quantity of liquid is sufficient to `' ~ . , .
, ~3~
satisfy the re~uest, the computer can at this point lower the tip, with reference to the free surface of the liquid, to a depth corresponding to the volume of liquid to be withdrawn, thus making it unnecessary to lower the tip more than necessary. The operation can be even more refined, by performing, in subsequent steps, small im-mersions of the tip with alternate suctioning of small volumes of liquid until the total volume to be withdrawn has been reached. In this manner only a small portion of the tip is maintained immersed in the liquid.
The sensors more commonly used to detect liquid levels are the capacity and resistivity types. Capacity sensors detect the difference in the dielectric constant, and therefore the capacity, when there are varia~ions in the media in which they are immersed. The resistivity sensors make use of the conductivity of the liquid in which they are immersed, which short-circuits the two electric con-tacts. Unfortunately the direct application of these sensors for the system in question would be impossible, for the following reasons:
1) - The different liquids to be suctionedr in order to prepare the dosages, have electric properties which differ; for instance, not all the liquids have good conductivity. Therefore, there is low reliability ~5 of the signals given by the sensors.
2) - The sensor should be Eastened to the tip o the z-axis which, as mentioned above, is not always the same, but is automatically replaced after each dis-pensing operation. Therefore it would be impractical and very expensive to have all tips with the sensors incorporated~
Even one of the commonly used pressure sensors, such as a piezometric resistivity pressure transducer, would not be directly applicable in this system. In act/ the use of such device in the dispensing system cannot give satisfactory results due to the low sensitivi~y of the ~3(~'7'~
pressure sensors available on the mark~t.
According to one aspect of khe invention there is provided a liquid level operated sensor suitable for use in connection with an automatic station for suction or dispensing of liquids in 5 containers which comprises a U-shaped container means having first and second legs, a conductive fluid in said container means and incompletely filling said container means, a resistivity sensor capable of providing an output signal disposed in the first leg of said container means, and means to connect the second leg to a lO pressure op~rated apparatus such that minimal change in the pressure in said apparatus is communicated to the conductive fluid in said container means and causes the conductive fluid to move into or out of contact with said sensor.
The invention is illustrated by the attached drawings in 15 which:
Figure 1 is a schematic illustration of a typical known automatic station;
Figure 2 is a schematic illustration of the automatic station of Figure 1 with the tip in contact with liquid;
Figure 3 is a schematic illustration of the liquid level sensor U-pipe of the present invention;
Figure 4 is a schematic illustration of the U-pipe of Figure 3 installed in a dispensing system; and Figure 5 is a schematic illustration of the system of 25 Figure 4 with the tip in contact with a liquid.
A typical ~utomatic station for preparing immunologic dosages will normally include a computer which controls the operations of a plotter for positloning a dispensing probe on a working surface containiny dosage trays. It also includes a 30 diluter connected to a probe for suction and dispensing of liquids.
Figures 1 and 2 schematically illustrate a theoretical solution of the proble~ of detecting a liquid level with the necessary degree of sensitivity by use of a pressure transducer~
35 The device includes a syringe 10 having a tube 11 connected thereto. The other end of the tube is connected to a T-connector 21. Also connected to the T-connector 21 is a pressure switch 12 and a plotter probe .i, , ~3~6t7~
or z-axis 13 at the bottom of which is connected a tip 14.
Figure 1 shows the situation where the tip 14 is not in contact with a liquid. Thus, air flows from the orifice of tip 14 and no internal pressure is created.
When tip 14 comes into contact with a liquid surface in a test tube 15, as shown in Figure 2, the orifice in the tip is blocked and a pressure is created which activates pressure switch 12. While this theoretically provides a solution, it has been found to be unsatisfactory because of the low sensitivity of existing devices.
The device of the present invention is illustrated in Figures 3, 4 and 5 and, looking first at Figure 3, a U-pipe is provided having a first arm or branch 17 and a second arm or branch 16. At the upper end of branch 16 is a resistivity sensor 18 which includes a first contact 19 and a second contact 20.
The U-pipe contains a conductive liquid, e.g. water W, and under atmospheric pressure the water surfaces in the two branches will be at the same level. However, if the pressure P in branch 17 is increased, the water level in this branch is lowered and the water level in branch 16 i5 raised. Since the resistivity sensor 18 i5 installed at the upper end of branch 16, when -the water in branch 16 has risen to an appropriate level, it comes lnto con-tact with the two contact wires 19 and 20. Contact 19 is connected ~o a voltage source V and, due to ~.he con-duotivity of the water W, this is transferred to contact 20, thereby generating a signal for use by a computer.
The device of Figure 4 may be used to detect liquid levels in test tubes by means of an arrangement as shown in Figure 4. Thus, the z-axis 13 of the preparing station is connected through one side of a T-member 21 and tube 11 to diluter syringe 10 and is connected through the other side of T-member 21 via tube 22 and valve 23 to branch 17 of the U-pipe. By moving up the piston of syringe 10, a movement of air is obtained in the direction of z-axis ~3C~6'~'~g 13. If the tip 14 of z-axis 13 is not in contact with a liquid surface, the air flows through the ori~ice of the tip itself. Moreover, if the syringe piston is moved up slowly, the air flows out slowly without creating any pressure within the system.
As soon as tip 14 comes into contact with liquid in a test tube 15, as shown in Figure 5, the air flow through the tip is stopped. This causes an immediate increase in pressure within the system and this pressure increase is transmitted to branch 17 causing a displacement of the water as shown in Figure 5. The increased liquid level in branch 16 activates the sensor 18 which transmits an electrical signal to the computer.
The valve 23 is preferably an electrically controlled valve and its purpose is to keep the connectîon open only during the time that the sensor level is being used. At other times, such as during suction and dispensing of liquids, the connection is closed. The valve is auto-matically activated and deactivated by the computer.
Even one of the commonly used pressure sensors, such as a piezometric resistivity pressure transducer, would not be directly applicable in this system. In act/ the use of such device in the dispensing system cannot give satisfactory results due to the low sensitivi~y of the ~3(~'7'~
pressure sensors available on the mark~t.
According to one aspect of khe invention there is provided a liquid level operated sensor suitable for use in connection with an automatic station for suction or dispensing of liquids in 5 containers which comprises a U-shaped container means having first and second legs, a conductive fluid in said container means and incompletely filling said container means, a resistivity sensor capable of providing an output signal disposed in the first leg of said container means, and means to connect the second leg to a lO pressure op~rated apparatus such that minimal change in the pressure in said apparatus is communicated to the conductive fluid in said container means and causes the conductive fluid to move into or out of contact with said sensor.
The invention is illustrated by the attached drawings in 15 which:
Figure 1 is a schematic illustration of a typical known automatic station;
Figure 2 is a schematic illustration of the automatic station of Figure 1 with the tip in contact with liquid;
Figure 3 is a schematic illustration of the liquid level sensor U-pipe of the present invention;
Figure 4 is a schematic illustration of the U-pipe of Figure 3 installed in a dispensing system; and Figure 5 is a schematic illustration of the system of 25 Figure 4 with the tip in contact with a liquid.
A typical ~utomatic station for preparing immunologic dosages will normally include a computer which controls the operations of a plotter for positloning a dispensing probe on a working surface containiny dosage trays. It also includes a 30 diluter connected to a probe for suction and dispensing of liquids.
Figures 1 and 2 schematically illustrate a theoretical solution of the proble~ of detecting a liquid level with the necessary degree of sensitivity by use of a pressure transducer~
35 The device includes a syringe 10 having a tube 11 connected thereto. The other end of the tube is connected to a T-connector 21. Also connected to the T-connector 21 is a pressure switch 12 and a plotter probe .i, , ~3~6t7~
or z-axis 13 at the bottom of which is connected a tip 14.
Figure 1 shows the situation where the tip 14 is not in contact with a liquid. Thus, air flows from the orifice of tip 14 and no internal pressure is created.
When tip 14 comes into contact with a liquid surface in a test tube 15, as shown in Figure 2, the orifice in the tip is blocked and a pressure is created which activates pressure switch 12. While this theoretically provides a solution, it has been found to be unsatisfactory because of the low sensitivity of existing devices.
The device of the present invention is illustrated in Figures 3, 4 and 5 and, looking first at Figure 3, a U-pipe is provided having a first arm or branch 17 and a second arm or branch 16. At the upper end of branch 16 is a resistivity sensor 18 which includes a first contact 19 and a second contact 20.
The U-pipe contains a conductive liquid, e.g. water W, and under atmospheric pressure the water surfaces in the two branches will be at the same level. However, if the pressure P in branch 17 is increased, the water level in this branch is lowered and the water level in branch 16 i5 raised. Since the resistivity sensor 18 i5 installed at the upper end of branch 16, when -the water in branch 16 has risen to an appropriate level, it comes lnto con-tact with the two contact wires 19 and 20. Contact 19 is connected ~o a voltage source V and, due to ~.he con-duotivity of the water W, this is transferred to contact 20, thereby generating a signal for use by a computer.
The device of Figure 4 may be used to detect liquid levels in test tubes by means of an arrangement as shown in Figure 4. Thus, the z-axis 13 of the preparing station is connected through one side of a T-member 21 and tube 11 to diluter syringe 10 and is connected through the other side of T-member 21 via tube 22 and valve 23 to branch 17 of the U-pipe. By moving up the piston of syringe 10, a movement of air is obtained in the direction of z-axis ~3C~6'~'~g 13. If the tip 14 of z-axis 13 is not in contact with a liquid surface, the air flows through the ori~ice of the tip itself. Moreover, if the syringe piston is moved up slowly, the air flows out slowly without creating any pressure within the system.
As soon as tip 14 comes into contact with liquid in a test tube 15, as shown in Figure 5, the air flow through the tip is stopped. This causes an immediate increase in pressure within the system and this pressure increase is transmitted to branch 17 causing a displacement of the water as shown in Figure 5. The increased liquid level in branch 16 activates the sensor 18 which transmits an electrical signal to the computer.
The valve 23 is preferably an electrically controlled valve and its purpose is to keep the connectîon open only during the time that the sensor level is being used. At other times, such as during suction and dispensing of liquids, the connection is closed. The valve is auto-matically activated and deactivated by the computer.
Claims (14)
1. A liquid level operated sensor suitable for use in connection with an automatic station for suction or dispensing of liquids in containers which comprises a U-shaped container means having first and second legs, a conductive fluid in said container means and incompletely filling said container means, a resistivity sensor capable of providing an output signal disposed in the first leg of said container means, and means to connect the second leg to a pressure operated apparatus such that minimal change in the pressure in said apparatus is communicated to the conductive fluid in said container means and causes the conductive fluid to move into or out of contact with said sensor.
2. The sensor of claim 1 wherein said means to connect comprises a valve means.
3. The sensor of claim 2 wherein said valve means is an electrically controlled valve means.
4. The sensor of claim 1 wherein said sensor is disposed in said first leg at a point which is normally out of contact with said conductive fluid.
5. The sensor of claim 4 wherein said sensor is disposed at the end of said first leg remote from said second leg.
6. The combination, a pressure operated apparatus and the liquid level operated sensor of claim 5.
7. The sensor of claim 1 further comprising means to cause the resistivity sensor to generate an output signal when in contact with said conductive fluid.
8. The sensor of claim 7 further comprising means to control the pressure in said apparatus in response to the output signal of said resistivity sensor operatively connected to said sensor.
9. In combination, a pressure operated apparatus and the liquid level operated sensor of claim 7.
10. In a method of operating an apparatus for liquid removal or dispensing into containers by altering the pressure in the apparatus, the improvement which comprises connecting the liquid level operated sensor of claim 7 to-said apparatus and adjusting the pressure within the apparatus in response to the output signal of the resistivity sensor.
11. The method of claim 10 in which the pressure adjustment is in response to the presence of the output signal.
12. The method of claim 10 in which the pressure adjustment is in response to the magnitude of the output signal.
13. The sensor of claim 1 wherein said U-shaped container is a U-shaped tube.
14. The sensor of claim 13 wherein said means to connect is an electrically operated valve and further comprising means to cause the resistivity sensor to generate an output signal when in contact with said conductive fluid and means to control both the pressure in the apparatus and the valve in response to the output signal of the sensor operatively connected to the sensor.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| IT48804A85 | 1985-11-18 | ||
| IT48804/85A IT1181735B (en) | 1985-11-19 | 1985-11-19 | LIQUID LEVEL SENSOR, USED IN AN AUTOMATIC STATION FOR THE PREPARATION OF IMMUNOLOGICAL DOSAGES |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1306779C true CA1306779C (en) | 1992-08-25 |
Family
ID=11268639
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000523105A Expired - Lifetime CA1306779C (en) | 1985-11-18 | 1986-11-17 | Liquid level sensor, used in an automatic station for preparing immunologic dosages |
Country Status (9)
| Country | Link |
|---|---|
| US (1) | US4777832A (en) |
| EP (1) | EP0223751B1 (en) |
| JP (1) | JP2593856B2 (en) |
| AT (1) | ATE68263T1 (en) |
| CA (1) | CA1306779C (en) |
| DE (2) | DE3681886D1 (en) |
| ES (1) | ES2000052T3 (en) |
| FI (1) | FI85190C (en) |
| IT (1) | IT1181735B (en) |
Families Citing this family (21)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS63109330A (en) * | 1986-10-27 | 1988-05-14 | Kyoto Daiichi Kagaku:Kk | Method and apparatus for detecting liquid level |
| CA1321940C (en) * | 1987-05-02 | 1993-09-07 | Teruaki Itoh | Apparatus for distributing sample liquid |
| US4986782A (en) * | 1989-11-24 | 1991-01-22 | Severtson Lyndon W | Liquid flow detector system |
| US5133392A (en) * | 1991-04-10 | 1992-07-28 | Eastman Kodak Company | Liquid injection using container bottom sensing |
| US5428993A (en) * | 1992-02-26 | 1995-07-04 | Toa Medical Electronics Co., Ltd. | Automatic analyzer having function of detecting remaining liquid quantity |
| ATE170293T1 (en) * | 1992-06-08 | 1998-09-15 | Behring Diagnostics Inc | FLUID DISPENSER SYSTEM |
| US6521187B1 (en) | 1996-05-31 | 2003-02-18 | Packard Instrument Company | Dispensing liquid drops onto porous brittle substrates |
| US6537817B1 (en) | 1993-05-31 | 2003-03-25 | Packard Instrument Company | Piezoelectric-drop-on-demand technology |
| US6203759B1 (en) | 1996-05-31 | 2001-03-20 | Packard Instrument Company | Microvolume liquid handling system |
| JP3318629B2 (en) * | 1993-06-18 | 2002-08-26 | ソニー株式会社 | Liquid suction / discharge device and method |
| US5750881A (en) * | 1995-07-13 | 1998-05-12 | Chiron Diagnostics Corporation | Method and apparatus for aspirating and dispensing sample fluids |
| US6158269A (en) * | 1995-07-13 | 2000-12-12 | Bayer Corporation | Method and apparatus for aspirating and dispensing sample fluids |
| US5915282A (en) * | 1995-12-14 | 1999-06-22 | Abbott Laboratories | Fluid handler and method of handling a fluid |
| US5723795A (en) * | 1995-12-14 | 1998-03-03 | Abbott Laboratories | Fluid handler and method of handling a fluid |
| US5965828A (en) * | 1995-12-14 | 1999-10-12 | Abbott Laboratories | Fluid handler and method of handling a fluid |
| US5665601A (en) * | 1996-01-22 | 1997-09-09 | Johnson & Johnson Clinical Diagnostics, Inc. | Avoiding bubble formation while sensing air-liquid interface using pressurized air flow |
| US6083762A (en) * | 1996-05-31 | 2000-07-04 | Packard Instruments Company | Microvolume liquid handling system |
| EP0810438B1 (en) * | 1996-05-31 | 2004-02-04 | Packard Instrument Company, Inc. | Microvolume liquid handling system |
| DE69827952T2 (en) * | 1997-04-08 | 2005-03-31 | Packard Instrument Co., Inc., Downers Grove | MIKROVOLUMENFLUESSIGKEITSHANDHABUNGSSYSTEM |
| CA3022672C (en) * | 2016-05-02 | 2020-12-29 | Roadtec, Inc. | Spray assembly for a working machine employing direct acting valves |
| US10401209B2 (en) | 2016-06-22 | 2019-09-03 | Abbott Laboratories | Liquid level sensing apparatus and related methods |
Family Cites Families (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2423397A (en) * | 1940-10-17 | 1947-07-01 | Lavigne Jean Loumiet Et | Steam boiler regulating system |
| GB844010A (en) * | 1958-08-05 | 1960-08-10 | Cai Moeller | Improvements in or relating to liquid level control devices |
| FR1342284A (en) * | 1962-09-26 | 1963-11-08 | Liquid level indicator and regulator | |
| US3477460A (en) * | 1965-08-02 | 1969-11-11 | Mallory & Co Inc P R | Fluid level control system |
| US3687289A (en) * | 1970-09-04 | 1972-08-29 | Ecodyne Corp | Water softener system |
| US3813945A (en) * | 1971-11-19 | 1974-06-04 | Nielsen Eng & Res Inc | Apparatus for extracting a liquid sample at various depths of a liquid stream |
| DE2655303A1 (en) * | 1976-12-07 | 1978-06-08 | Walter Schweikert | Fluid flow control in bakeries - uses level sensor in supply tanks to maintain constant level and control outflow through base valve |
| JPS56164958A (en) * | 1980-05-23 | 1981-12-18 | Aloka Co Ltd | Automatic dispenser |
| JPS5952759A (en) * | 1982-09-20 | 1984-03-27 | Terumo Corp | Drawing and dispensing device for sample |
-
1985
- 1985-11-19 IT IT48804/85A patent/IT1181735B/en active
-
1986
- 1986-11-14 US US06/930,642 patent/US4777832A/en not_active Expired - Lifetime
- 1986-11-17 AT AT86830346T patent/ATE68263T1/en not_active IP Right Cessation
- 1986-11-17 EP EP86830346A patent/EP0223751B1/en not_active Expired - Lifetime
- 1986-11-17 DE DE8686830346T patent/DE3681886D1/en not_active Expired - Lifetime
- 1986-11-17 DE DE198686830346T patent/DE223751T1/en active Pending
- 1986-11-17 ES ES198686830346T patent/ES2000052T3/en not_active Expired - Lifetime
- 1986-11-17 CA CA000523105A patent/CA1306779C/en not_active Expired - Lifetime
- 1986-11-18 FI FI864697A patent/FI85190C/en not_active IP Right Cessation
- 1986-11-18 JP JP61273045A patent/JP2593856B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| DE223751T1 (en) | 1987-11-05 |
| FI864697A0 (en) | 1986-11-18 |
| US4777832A (en) | 1988-10-18 |
| JPS62119458A (en) | 1987-05-30 |
| IT8548804A0 (en) | 1985-11-19 |
| FI85190B (en) | 1991-11-29 |
| JP2593856B2 (en) | 1997-03-26 |
| ATE68263T1 (en) | 1991-10-15 |
| IT1181735B (en) | 1987-09-30 |
| FI85190C (en) | 1992-03-10 |
| EP0223751A3 (en) | 1988-06-08 |
| EP0223751A2 (en) | 1987-05-27 |
| ES2000052A4 (en) | 1987-11-16 |
| DE3681886D1 (en) | 1991-11-14 |
| FI864697A (en) | 1987-05-20 |
| EP0223751B1 (en) | 1991-10-09 |
| ES2000052T3 (en) | 1992-06-16 |
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