GB2570495A - Flow detection device and method for detecting a flow of liquid - Google Patents
Flow detection device and method for detecting a flow of liquid Download PDFInfo
- Publication number
- GB2570495A GB2570495A GB1801408.4A GB201801408A GB2570495A GB 2570495 A GB2570495 A GB 2570495A GB 201801408 A GB201801408 A GB 201801408A GB 2570495 A GB2570495 A GB 2570495A
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- Prior art keywords
- flow
- detection device
- restricting element
- detecting
- liquid
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01F—MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
- G01F1/00—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow
- G01F1/05—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow by using mechanical effects
- G01F1/20—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow by using mechanical effects by detection of dynamic effects of the flow
- G01F1/28—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow by using mechanical effects by detection of dynamic effects of the flow by drag-force, e.g. vane type or impact flowmeter
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01L—CHEMICAL OR PHYSICAL LABORATORY APPARATUS FOR GENERAL USE
- B01L3/00—Containers or dishes for laboratory use, e.g. laboratory glassware; Droppers
- B01L3/02—Burettes; Pipettes
- B01L3/021—Pipettes, i.e. with only one conduit for withdrawing and redistributing liquids
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01L—CHEMICAL OR PHYSICAL LABORATORY APPARATUS FOR GENERAL USE
- B01L3/00—Containers or dishes for laboratory use, e.g. laboratory glassware; Droppers
- B01L3/02—Burettes; Pipettes
- B01L3/021—Pipettes, i.e. with only one conduit for withdrawing and redistributing liquids
- B01L3/0213—Accessories for glass pipettes; Gun-type pipettes, e.g. safety devices, pumps
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01L—CHEMICAL OR PHYSICAL LABORATORY APPARATUS FOR GENERAL USE
- B01L3/00—Containers or dishes for laboratory use, e.g. laboratory glassware; Droppers
- B01L3/02—Burettes; Pipettes
- B01L3/021—Pipettes, i.e. with only one conduit for withdrawing and redistributing liquids
- B01L3/0217—Pipettes, i.e. with only one conduit for withdrawing and redistributing liquids of the plunger pump type
- B01L3/0237—Details of electronic control, e.g. relating to user interface
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01F—MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
- G01F25/00—Testing or calibration of apparatus for measuring volume, volume flow or liquid level or for metering by volume
- G01F25/10—Testing or calibration of apparatus for measuring volume, volume flow or liquid level or for metering by volume of flowmeters
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01P—MEASURING LINEAR OR ANGULAR SPEED, ACCELERATION, DECELERATION, OR SHOCK; INDICATING PRESENCE, ABSENCE, OR DIRECTION, OF MOVEMENT
- G01P13/00—Indicating or recording presence, absence, or direction, of movement
- G01P13/0006—Indicating or recording presence, absence, or direction, of movement of fluids or of granulous or powder-like substances
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01P—MEASURING LINEAR OR ANGULAR SPEED, ACCELERATION, DECELERATION, OR SHOCK; INDICATING PRESENCE, ABSENCE, OR DIRECTION, OF MOVEMENT
- G01P13/00—Indicating or recording presence, absence, or direction, of movement
- G01P13/0006—Indicating or recording presence, absence, or direction, of movement of fluids or of granulous or powder-like substances
- G01P13/0026—Indicating or recording presence, absence, or direction, of movement of fluids or of granulous or powder-like substances by using deflection of baffle-plates
- G01P13/0033—Indicating or recording presence, absence, or direction, of movement of fluids or of granulous or powder-like substances by using deflection of baffle-plates with electrical coupling to the indicating device
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01P—MEASURING LINEAR OR ANGULAR SPEED, ACCELERATION, DECELERATION, OR SHOCK; INDICATING PRESENCE, ABSENCE, OR DIRECTION, OF MOVEMENT
- G01P21/00—Testing or calibrating of apparatus or devices covered by the preceding groups
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01P—MEASURING LINEAR OR ANGULAR SPEED, ACCELERATION, DECELERATION, OR SHOCK; INDICATING PRESENCE, ABSENCE, OR DIRECTION, OF MOVEMENT
- G01P5/00—Measuring speed of fluids, e.g. of air stream; Measuring speed of bodies relative to fluids, e.g. of ship, of aircraft
- G01P5/02—Measuring speed of fluids, e.g. of air stream; Measuring speed of bodies relative to fluids, e.g. of ship, of aircraft by measuring forces exerted by the fluid on solid bodies, e.g. anemometer
- G01P5/04—Measuring speed of fluids, e.g. of air stream; Measuring speed of bodies relative to fluids, e.g. of ship, of aircraft by measuring forces exerted by the fluid on solid bodies, e.g. anemometer using deflection of baffle-plates
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- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Health & Medical Sciences (AREA)
- Clinical Laboratory Science (AREA)
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Fluid Mechanics (AREA)
- Engineering & Computer Science (AREA)
- Aviation & Aerospace Engineering (AREA)
- Human Computer Interaction (AREA)
- Measuring Volume Flow (AREA)
- Indicating Or Recording The Presence, Absence, Or Direction Of Movement (AREA)
Abstract
Various flow detection devices 10, 100 (see all figs) are disclosed for detecting a flow of liquid in a measuring chamber 1. The flow detection devices comprise a flow restricting element 2 and a detecting element 3. The flow restricting element 2 is operatively coupled to an inner surface of the measuring chamber 1 and configured to apply a reset force against the flow of liquid. The detecting element 3 senses the flow restricting element 2. The flow restricting element 2 may be a foil hinged flap. The hinged flap may be injection molded to at least one part of the inner surface of the measuring chamber. The flow restricting element may comprise a reset spring 22 and at least one stopper 23. The flow restricting element may comprise a duckbill check valve 4 comprising a deforming snout part 41. The detecting element 3 may be an optical detection element comprising a transmitting member 31, 32, a light barrier beam 31 for sensing the movement of the flow restricting element, and a receiving member 33. The flow restricting element may comprise a flag member 21A. The snout 41 of the flow restricting element may cause a lensing effect, figs 8A, 8B. The detecting element may alternatively be an electrical detection element and may be at least partially embedded in the flow restricting element 2. The electrical detection element may comprise at least one conductive part 34 and at least one electrode part 35A, 35B, 36A, 36B for detecting capacitance. Alternatively the electrical detection element may be a resistance strain gauge 37A, 37B, a foil piezo element 38A or a piezo resistive foil 38B. A method of qualitative detecting a flow of liquid is claimed comprising comparing movement of the flow restricting element 2 with a threshold. A method for quantitative detecting a flow measurement is claimed. The method comprises assessing the amplitude of the movement of the flow restricting element proportionally to the flow of the liquid and calibrating the amplitude of the movement of the flow restricting element. The flow detection devices may be used to detect flow of liquid in a pipettor for controlling rinsing processes.
Description
Description
Title: Flow Detection Device and Method for Detecting a Flow of Liquid
Field of the invention [0001] The invention relates to a flow detection device for detecting a flow of liquid in a measuring chamber. The invention also relates to a method using the device for detecting a flow of liquid in a measuring chamber. The invention also relates to the use of the device for detecting a flow of liquid in a pipettor for controlling rinsing processes.
Background of the invention [0002] There is a broad range of flow detecting devices on the market. However, known flow detection devices contacting the liquid, e.g. thermal sensors, semiconductor devices, bring metal in contact with the measured liquid in the measuring chambers (e.g. as a part of pipettors). Known flow detection devices without contacting the liquid are however often physically delicate and therefore susceptible to external perturbation, i.e. not very robust. Further, commercially available flow detection devices usually are only quantitative measuring, which increases costs on sensor and analysis side. Therefore, the commercially available flow detection devices are all quite expensive and not very robust.
[0003] Therefore, there is a need for appropriate flow detection devices for detecting a flow of liquid in a measuring chamber for a robust, low cost solution suitable for process control of pipettor rinsing processes.
Object of the invention [0004] It is an object of the present invention to provide a robust and low cost flow detection device for detecting a flow of liquid in a measuring chamber.
Summary of the invention
-2[0005] In view of the state of the known technology and in accordance with one aspect of the present invention a flow detection device for detecting a flow of liquid in a measuring chamber is provided that comprises flow restricting element and a detecting element. The flow restricting element is operatively coupled to an inner surface of the measuring chamber and configured to apply a reset force against the flow of liquid. The detecting element senses the flow restricting element for detecting the flow of liquid in the measuring chamber.
[0006] The present invention provides further that the flow restricting element is configured to apply a reset force against the flow of liquid at flow rates of about 1-10 ml/s.
[0007] The present invention provides further that the flow restricting element is formed of an inert plastic material.
[0008] The present invention provides even further that the measuring chamber is a tubing (e.g. in a pipettor) having at least one of a square section and a circular section.
[0009] The present invention provides further that the flow restricting element is a hinged flap comprising a flap with a foil hinge fixed on at least one side of the flap.
[0010] The present invention provides even further that the flap of the hinged flap has a surface area corresponding to the at least one of the square section and the circular section of the measuring chamber.
[0011] The present invention provides further that the surface area of the flap of the hinged flap is between 1-20 mm2 corresponding to the diameter of the measuring chamber between 1-5 mm.
[0012] The present invention provides further that the hinged flap is injection-molded.
[0013] The present invention provides further that the hinged flap is molded to at least one part of the inner surface of the measuring chamber and configured to be moved between a first position and second position.
-3[0014] The present invention provides even further that the flow restricting element further comprises at least one reset spring to return the flow restricting element to the first position.
[0015] The present invention provides further that the flow restricting element further comprises at least one stopper oppositely arranged to the at least one reset spring, wherein the flow restricting element is arranged between the at least one stopper and the least one reset spring.
[0016] The present invention provides further that the flow restricting element includes a duckbill check valve comprising a deforming part for using elastic forces as reset force against the flow of liquid.
[0017] The present invention provides further that the detecting element is configured as an optical detection element comprising a transmitting member and a receiving member.
[0018] The present invention provides further that the transmitting member of the optical detection element includes a light barrier beam for sensing the movement of the flow restricting element.
[0019] The present invention provides further that flow restricting element comprises a flag member to be sensed by the light barrier beam.
[0020] The present invention provides further that the transmitting member of the optical detection element includes at least one light beam and wherein the receiving member of the optical detection element includes a light detector.
[0021] The present invention provides further that the flow restricting element is configured to cause a lensing effect to be detected by the optical detection element, when the flow restricting element is moved.
[0022] The present invention provides further that the detecting element is configured as an electrical detection element.
-4[0023] The present invention provides further that the electrical detection element is at least partially embedded in the flow restricting element.
[0024] The present invention provides further that electrical detection element comprises at least one conductive part and at least one electrode part for detecting the capacity, when the flow restricting element is moved.
[0025] The present invention provides further that the electrical detection element is configured as a resistive strain gauge.
[0026] The present invention provides further that electrical detection element is configured as a foil piezo element or a piezo resistive foil.
[0027] In view of the state of the known technology and in accordance with a further aspect of the present invention a method for qualitative detecting a flow of liquid in a measuring chamber with a flow detection device is provided, comprising the method steps of: inflowing liquid into the measuring chamber, applying a reset force against the flow of liquid by the flow restricting element, detecting the movement of the flow restricting element by the detecting element, and comparing the detected movement of the flow restricting element with a threshold.
[0028] In view of the state of the known technology and in accordance with an even further aspect of the present invention a method for quantitative detecting a flow measurement of a liquid in a measuring chamber with a flow detection device is provided, comprising the method steps of: inflowing liquid into the measuring chamber, applying a reset force against the flow of liquid by the flow restricting element, detecting the movement of the flow restricting element by the detecting element, assessing the amplitude of the movement of the flow restricting element proportionally to the flow of the liquid, and calibrating the amplitude of the movement the flow restricting element.
[0029] In view of the state of the known technology and in accordance with an even further aspect of the present invention the flow detection device for detecting a flow of liquid is used in a pipettor for controlling rinsing processes.
-5[0030] The advantages of the invention of the present disclosure can be summarized as follows:
a. A robust method and device for detecting the flow of liquid is provided.
b. A low cost method and device for detecting the flow of liquid is provided.
c. A method and device for detecting the flow of liquid at flow rates of 1-10 ml/s is provided.
d. A method and device for detecting the flow of liquid is provided without bringing metal in contact with the detected liquid.
e. A method and device for qualitative and quantitative detecting the flow of liquid is provided.
Summary of the figures [0031] The invention will now be described on the basis of figures. It will be understood that the embodiments and aspects of the invention described in the figures are only examples and do not limit the protective scope of the claims in any way. The invention is defined by the claims and their equivalents. It will be understood that features of one aspect or embodiment of the invention can be combined with a feature of a different aspect or aspects of other embodiments of the invention. It shows:
| [0032] Figure 1 | Cross-sectional side view of a measuring chamber with the flow detection device in accordance with a first embodiment. |
| [0033] Figure 2 | Cross-sectional side view of the flow detection device with a modified flow restricting element in accordance with the first embodiment. |
| [0034] Figure 3A | Cross-sectional side view of the flow detection device of Fig. 2 with a modified flow restricting element in accordance with the first embodiment. |
| [0035] Figure 3B | Cross-sectional side view of the flow detection device of Fig. 2 with a modified detecting element in accordance with the first embodiment. |
| [0036] Figure 4A | Cross-sectional side view of the flow detection device of Fig. 2 with a modified detecting element in accordance with the first embodiment. |
| [0037] Figure 4B | Cross-sectional side view of the flow detection device of Fig. 2 with a modified detecting element and a modified flow restricting element in accordance with the first embodiment. |
| [0038] Figure 5 A | Cross-sectional side view of a measuring chamber with a flow detection device in accordance with a second embodiment in view of a first position. |
| [0039] Figure 5B | Cross-sectional front view of the flow detection device of Fig. 5A. |
| [0040] Figure 5C | Cross-sectional side view of the measuring chamber with the flow detection device of Fig. 5A in view of a second position. |
| [0041] Figure 5D | Cross-sectional view of the flow detection device of Fig. 5C. |
| [0042] Figure 6A | Cross-sectional side view of the flow detection device of Fig. 5A with a modified flow restricting element in accordance with the second embodiment. |
| [0043] Figure 6B | Cross-sectional view of the flow detection device of Fig. 6A. |
| [0044] Figure 7 | Cross-sectional side view of the flow detection device of Fig. 5A with a modified detecting element in accordance with the second embodiment. |
| [0045] Figure 8A | Cross-sectional side view of the flow detection device of Fig. 5A with a modified detecting element in accordance with the second embodiment in view of a first position. |
| [0046] Figure 8B | Cross-sectional side view of the measuring chamber with the flow detection device of Fig. 8A in view of a second position. |
| [0047] Figure 9A | Cross-sectional side view of the flow detection device of Fig. 5A with a modified detecting element in accordance with the second embodiment. |
| [0048] Figure 9B | Cross-sectional side view of the flow detection device of Fig. 5A with a modified detecting element in accordance with the second embodiment. |
| [0049] Figure 10A | Cross-sectional side view of the flow detection device of Fig. 5A with a modified detecting element in accordance with the second embodiment in view of a first position. |
| [0050] Figure 10B | Cross-sectional side view of the measuring chamber with the flow detection device of Fig. 10A in view of a second position. |
| [0051] Figure 11 | Flowchart of a method for qualitative detecting a flow of liquid in a measuring chamber. |
| [0052] Figure 12 | Flowchart of a method for quantitative detecting a flow of liquid in a measuring chamber. |
| [0053] Figure 13A | Side view of a Piezo element. |
| [0054] Figure 13B | Side view of a Piezo element. |
Detailed description of the present invention [0055] The object of the present invention is fully described below using examples for the purpose of disclosure, without limiting the disclosure to the examples. The examples present different aspects of the present invention. To implement the present technical
-8teaching, it is not required to implement all of these aspects combined. Rather, a specialist will select and combine those aspects that appear sensible and required for the corresponding application and implementation.
First embodiment [0056] Fig. 1 shows a cross-sectional side view of a measuring chamber 1, e.g. as a part of a pipettor or suction needle, with the flow detection device 10 in accordance with a first embodiment. The flow detection device 10 comprises a flow restricting element 2 and a detecting element 3. The flow restricting element 2 is operatively coupled to an inner surface of the measuring chamber 1 and configured to apply a reset force against the flow of liquid. As can be seen in Fig. 1, the flow restricting element 2 is formed as a hinged flap 21 comprising a flap with a foil hinge fixed on at least one side of the flap. The measuring chamber 1 is a tubing having a square section. However, the present invention is not limited to this embodiment, a tubing can also have a circular section, as needed and/or desired. In order to provide significant resistance to the flow of liquid in a desired flow rate range the surface area of a flap of the hinged flap 21 is between 1-20 mm2 corresponding to the diameter of the measuring chamber 1 between 1-5 mm.
[0057] The flow restricting element 2 with the hinged flap 21 is configured to apply a reset force against the flow of liquid at flow rates of about 1-10 ml/s. In order to avoid any metal contact with the liquid, the entire hinged flap 21 is made of inert plastic material. However, the present invention is not limited to this embodiment, the hinged flap 21 is made at least partly of inert plastic material, as needed and/or desired. Further, in order to have low costs, the entire hinged flap 21 is injection-molded. As can be seen in Fig. 1, the hinged flap 21 is molded to one side of the inner surface of the measuring chamber 1 and is configured to be moved by the flow of liquid between a first position, i.e. an initial position, and second position, i.e. an actuated position, when the flow of liquid flows through the measuring chamber 1 in the flow direction DI. In particular, the hinged flap 21 is molded to at least one part of the tubing, wherein the at least one part of the tubing can be integrally formed with the inner surface of the measuring chamber 1 or the at least one part of the tubing can be separately formed with the inner surface of the measuring chamber 1. Further, as can be seen in Fig. 1, the flow detection device 10 comprises a
-9detecting element 3 for sensing the flow restricting element 2. In particular, the detecting element 3 senses the hinged flap 21 for detecting whether the hinged flap 21 is in one of the first or second position for detecting whether the flow of liquid is present or not.
[0058] Fig. 2 shows a cross-sectional side view of the flow detection device 10 with a modified flow restricting element 2 in accordance with the first embodiment. As can be seen in Fig. 2, the flow restricting element 2 further comprises at least one reset spring 22 to return the flow restricting element 2 back to the first position, i.e. the initial position in the orthogonal position when no flow is present. In the present embodiment, the reset spring 22 is formed as a single sided reset spring to allow unidirectional flow. Further, as can be seen in Fig. 2, the flow restricting element 2 further comprises at least one stopper 23 oppositely arranged to the at least one reset spring 22, wherein the flow restricting element 2 is arranged between the at least one stopper 23 and the least one reset spring 22.
[0059] As can be seen in Figs. 1 and 2, the detecting element 3 is configured as an optical detection element 3. In particular, with transparent liquids and transparent molded inert plastic parts, the optical detection element 3 includes a light barrier beam 31 for sensing the movement of the flow restricting element 2 through the flow detection device 10 orthogonal to the moving flow restricting element 2 and orthogonal to the plane of movement of the flow restricting element 2. In particular, the light barrier beam 31 senses the movement of the hinged flap 21 between at least one of the first and second position depending whether the flow of liquid in the measuring chamber 1 is present or not. The hinged flap 21 is molded from non-transparent material and could carry a flag member 21A to be sensed by the light barrier beam 31 creating a clean edge in the direction of the movement of the hinged flap 21 for ensuring optimal detecting result by the light barrier beam 31, as can be seen in Fig. 3A. The flag member 21A could be integrally formed with the hinged flap 21 or could be separately formed with the hinged flap 21, as needed and or desired. In particular, the flag member 21A could be molded on the hinged flap 21.
[0060] Fig. 3B shows a cross-sectional side view of the flow detection device 10 of Fig. 2 with a modified detecting element 3 in accordance with the first embodiment. The detecting element 3 is modified such that the detecting element 3 is also configured as an optical detection element now comprising a transmitting member 32 and a receiving
-10member 33. In particular, with transparent liquids and transparent molded inert plastic parts, the transmitting member 32 of the optical detection element 3 includes at least one light beam 32. The optical detection element 3 further includes a light detector 33 as the receiving member. The light beam 32 can be transmitted through the flow detection device 10 orthogonal to the moving flow restricting element 2, but in the plane of movement of the flow restricting element 2, as can be seen in Fig. 3B. The hinged flap 21 has a sufficiently reflective smooth surface. As can be seen in Fig. 3B, the light beam 32 is directed onto the surface of the hinged flap 21 at an angle of total reflection and is diverted as the flow of liquid is present in the measuring chamber 1.
[0061] With non-transparent fluids and/or technical needs to use non-transparent materials electrical detection of the flow restricting element 2 is still possible. Fig. 4A shows a cross-sectional side view of the flow detection device 10 of Fig. 2 with a further modified detecting element 3 in accordance with the first embodiment. In particular, the detecting element 3 is configured as an electrical detection element 3. In order to avoid contact between metal and the liquid the electrical detection element 3 needs to be embedded in the molded flow restricting element 2. In particular, the electrical detection element 3 comprises at least one conductive part 34 and at least one electrode part 35A, 35B for detecting the capacity, when the flow restricting element 2 is moved. The at least one conductive part 34 is at least partially embedded in the flow restricting element 2, the at least one conductive part 34 is at least partially embedded in the hinged flap 21. The conductive part 34 can be formed as foil sheet or wire embedded in the hinged flap 21 with counter electrodes 35A and 35B outside of the measuring chamber 1. The capacity reduces as flow of liquid is present in the measuring chamber 1.
[0062] Fig. 4B shows a cross-sectional side view of the flow detection device 10 with a further modified detecting element 3 and a modified flow restricting element 2 in accordance with the first embodiment. As can be seen in Fig. 4B, the reset spring 22 is formed as a double sided reset spring to allow bidirectional flow. The stopper 23 is omitted with the modified flow restricting element 2. Further, the detecting element 3 is also configured as an electrical detection element 3. In order to avoid contact between metal and the liquid the electrical detection element 3 needs to be embedded in the molded flow
-11restricting element 2. In particular, the electrical detection element 3 comprises at least one conductive part 34 and two ring electrode parts 36A, 36B for detecting the capacity, when the flow restricting element 2 is moved. The conductive part 34 is at least partially embedded in the flow restricting element 2, the at least one conductive part 34 is at least partially embedded in the hinged flap 21. The conductive part 34 can be formed as foil sheet or wire embedded in the hinged flap 21 with ring counter electrodes 36A and 36B outside of the measuring chamber 1. The ring counter electrodes 36A and 36B are laterally arranged to each other with an offset outside of the measuring chamber 1. Whether the capacity increases or decreases depends on the measured electrodes or flow direction. For the first electrode pair in the flow direction, the capacitance falls, and the capacitance increases for the second pair.
[0063] With the double sided reset spring 22 to allow bidirectional flow and the ring counter electrodes 36A and 36B a detection of the flow direction D2 of the flow of liquid is allowed.
[0064] Further, a foil piezo element 38A, as can be seen in Figs. 13A and 13B, or a piezo resistive foil 38B, as can be seen in Figs. 13A and 13B, can be used as the hinged flap 21. Due to the bending of the foil, the resistance of the foil changes or the foil itself generates a voltage. Either can be measured. The foils are small and for example integral formed into a valve or a pump. Only an intermediate plate is needed. The required reset force is provided by the elasticity of the foil itself.
Second embodiment [0065] Fig. 5A shows a cross-sectional side view of a measuring chamber 1, as a part of a pipettor or suction needle, with a flow detection device 100 in accordance with a second embodiment. The flow detection device 100 comprises a flow restricting element 2 and a detecting element 3. As can be seen in Fig. 5B, the measuring chamber 1 is a tubing having a circular section. However, the present invention is not limited to this embodiment, a tubing can also have a square section, as needed and/or desired. The flow restricting element 2 is operatively coupled to an inner surface of the measuring chamber 1 and configured to apply a reset force against the flow of liquid. As can be seen in Figs. 5A to
-125D, the flow restricting element 2 of the second embodiment includes a duckbill check valve 4 comprising a deforming part 41, i.e. so called “snout”, for using elastic forces as reset force against the flow of liquid in the measuring chamber 1. The duckbill check valve 4 uses elastic forces of the elastomer from which the duckbill is formed as reset force to close the duckbill when no or reverse flow of liquid is present in the measuring chamber 1. The deforming part 41, i.e. so called “snout”, of the duckbill check valve itself gets deformed when flow is present, as can be seen in Figs. 5C and 5D. Further, as can be seen in Fig. 5A, the flow detection device 100 comprises a detecting element 3 for sensing the deformation of the deforming part 41. In particular, the detecting element 3 senses the deforming part 41 for detecting whether the whether the flow of liquid is present or not. Fig. 5B shows a cross-sectional front view of the flow detection device 100 of Fig. 5A illustrating a non-deformed state of the deforming part 41, i.e. a state in which no flow of liquid is present. In contrary, Fig. 5D shows a cross-sectional front view of the flow detection device 100 of Fig. 5C illustrating a deformed state of the deforming part 41, i.e. a state in which flow of liquid is present.
[0066] As can be seen in Figs. 5A and 5C, the detecting element 3 is configured as an optical detection element 3. In particular, with transparent liquids and transparent elastomer parts, the optical detection element 3 includes a light barrier beam 31 for sensing the deformation of the flow deforming part 41 through the flow detection device 100 orthogonal to the deforming part 41 and orthogonal to the plane of deformation of the deforming part 41. The duckbill check valve 4 is molded from non-transparent material and could carry a flag member 21A to be sensed by the light barrier beam 31 creating a clean edge in the direction of the deformation of the deforming part 41 for ensuring optimal detecting result by the light barrier beam 31, as can be seen in Fig. 6A. The flag member 21A could be integrally formed with the deforming part 41 or could be separately formed with the deforming part 41, as needed and or desired. In particular, the flag member 21A could be molded on the deforming part 41.
[0067] Fig. 7 shows a cross-sectional side view of the flow detection device 100 of Fig. 5A with a modified detecting element 3 in accordance with the second embodiment. The detecting element 3 is modified such that the detecting element 3 is also configured as an optical detection element now comprising a transmitting member 32 and a receiving
-13member 33. In particular, with transparent liquids and transparent molded elastomer parts, the transmitting member 32 of the optical detection element 3 includes at least one light beam 32. The optical detection element 3 further includes a light detector 33 as the receiving member. The light beam 32 can be transmitted through the flow detection device 100 orthogonal to the moving flow restricting element 2, but in the plane of deformation of the deforming part 41, as can be seen in Fig. 7. The deforming part 41 has a sufficiently reflective smooth surface. As can be seen in Fig. 7, the light beam 32 is directed onto the surface of the hinged flap 21 at an angle of total reflection and is diverted as the flow of liquid is present in the measuring chamber 1.
[0068] A further modification of the flow detection device 100 of Fig. 7 is shown in Figs. 8A and 8B. The flow restricting element 2, in particular the deforming part 41, is configured to cause a lensing effect to be detected by the optical detection element 3, when the flow restricting element 2, in particular the deforming part 41, is deformed. Therefore, an intensity modulation is used for detection. The duckbill check valve 4 provides an additional optical detection opportunity. If the duckbill check valve 4 is molded from transparent material, at least in the wavelength used for sensing, usually IR, the deformation of the deforming part 41, i.e. the snout, can cause the lensing effect. Therefore, as can be seen in Fig. 8B, the lensing effect of the deforming part 41 leads to an intensity modulation of the detected light when the flow of liquid is present.
[0069] With non-transparent fluids and/or technical needs to use non-transparent materials electrical detection of the flow restricting element 2 is still possible. Fig. 9A shows a cross-sectional side view of the flow detection device 100 of Fig. 5A with a further modified detecting element 3 in accordance with the second embodiment. In particular, the detecting element 3 is configured as an electrical detection element 3. In order to avoid contact between metal and the liquid the electrical detection element 3 needs to be embedded in the molded two halves of the duckbill check valve 4. In particular, the electrical detection element 3 comprises at least one conductive part 34 and at least one electrode part 35A, 35B for detecting the capacity, when the duckbill check valve 4 is deformed. The at least one conductive part 34 is at least partially embedded in the halves of the duckbill check valve 4, the at least one conductive part 34 is at least partially embedded in the deforming part 41. The conductive part 34 can be formed as foil sheet or
-14wire embedded in the halves of the duckbill check valve 4 with counter electrodes 35A and 35B outside of the measuring chamber 1. The capacity reduces as flow of liquid is present in the measuring chamber 1.
[0070] Fig. 9B shows a cross-sectional side view of the flow detection device 100 with a further modified detecting element 3 in accordance with the second embodiment. As can be seen in Fig. 9B, the detecting element 3 is also configured as an electrical detection element 3. In order to avoid contact between metal and the liquid the electrical detection element 3 needs to be embedded in the molded flow restricting element 2. In particular, the electrical detection element 3 comprises at least one conductive part 34 and a ring electrode part 36A for detecting the capacity, when the flow restricting element 2 is deformed. The conductive part 34 is at least partially embedded in the halves of the duckbill check valve 4. The conductive part 34 can be formed as foil sheet or wire embedded in the halves of the duckbill check valve 4 with ring counter electrode 36A outside of the measuring chamber l.The capacity increases as flow of liquid is present in the measuring chamber 1.
[0071] Figs. 10A and 10B show a cross-sectional side view of the flow detection device 100 of Fig. 5A with a further modified detecting element 3 in accordance with the second embodiment. In particular, the deformation of the elastomer of the duckbill check valve 4 is detectable by a resistive strain gauge 37A, 37B that is embedded in the elastomer of the halves of the duckbill check valve 4, in particular the deforming part 41, i.e. “snout”, during molding.
[0072] As can be seen in Fig. 11, a flowchart is provided for illustrating the method steps for qualitative detecting a flow of liquid in the measuring chamber 1 with the flow detection device 10, 100, the method comprising: inflowing 200 liquid into the measuring chamber 1; applying 210 a reset force against the flow of liquid by the flow restricting element 2; detecting 220 the movement of the flow restricting element 2 by the detecting element 3; and comparing 230 the detected movement of the flow restricting element 2 with a threshold.
-15[0073] As can be seen in Fig. 12, a flowchart is provided for illustrating the method steps for quantitative detecting a flow of liquid in the measuring chamber 1 with the flow detection device 10, 100, the method comprising: inflowing 300 liquid into the measuring chamber 1; applying 310 a reset force against the flow of liquid by the flow restricting element 2; detecting 320 the movement of the flow restricting element 2 by the detecting element 3; assessing 330 the amplitude of the movement of the flow restricting element 2 proportionally to the flow of the liquid; and calibrating 340 the amplitude of the movement the flow restricting element 2.
[0074] In accordance with an even further aspect of the present invention the flow detection device 10, 100 for detecting a flow of liquid is used in a pipettor for controlling rinsing processes.
-16Reference Number List
10, 100
31,32
35A, 35B
36A, 36B
37A, 37B
38A
38B measuring chamber flow restricting element detecting element duckbill check valve flow detection device hinged flap reset spring stopper transmitting member receiving member conductive part electrode part electrode part resistive strain gauge foil piezo element piezo resistive foil
Claims (25)
1. A flow detection device (10, 100) for detecting a flow of liquid in a measuring chamber (1), the flow detection device (10, 100) comprising:
a flow restricting element (2) operatively coupled to an inner surface of the measuring chamber (1) and configured to apply a reset force against the flow of liquid; and a detecting element (3) for sensing the flow restricting element (2).
2. The flow detection device (10, 100) according to claim 1, wherein the flow restricting element (2) is configured to apply a reset force against the flow of liquid at flow rates of about 1-10 ml/s.
3. The flow detection device (10, 100) according to claim 1 or 2, wherein the flow restricting element (2) is formed of an inert plastic material.
4. The flow detection device (10, 100) according to any one of claims 1 to 3, wherein the measuring chamber (1) is a tubing having at least one of a square section and a circular section.
5. The flow detection device (10) according to any one of claims 1 to 4, wherein the flow restricting element (2) is a hinged flap (21) comprising a flap with a foil hinge fixed on at least one side of the flap.
6. The flow detection device (10) according to claim 5, wherein the flap of the hinged flap (21) has a surface area corresponding to the at least one of the square section and the circular section of the measuring chamber (1).
7. The flow detection device (10) according to claim 6, wherein the surface area of the flap of the hinged flap (21) is between 1-20 mm2 corresponding to the diameter of the measuring chamber (1) between 1-5 mm.
8. The flow detection device (10) according to any one of claims 4 to 7, wherein the hinged flap (21) is injection-molded.
9. The flow detection device (10) according to any one of claims 5 to 8, wherein the hinged flap (21) is molded to at least one part of the inner surface of the measuring chamber (1) and configured to be moved between a first position and second position.
10. The flow detection device (10) according to any one of claims 1 to 9, wherein the flow restricting element (2) further comprises at least one reset spring (22) to return the flow restricting element (2) to the first position.
11. The flow detection device (10) according to claim 10, wherein the flow restricting element (2) further comprises at least one stopper (23) oppositely arranged to the at least one reset spring (22), wherein the flow restricting element (2) is arranged between the at least one stopper (23) and the least one reset spring (22).
12. The flow detection device (100) according to any one of claims 1 to 4, wherein the flow restricting element (2) includes a duckbill check valve (4) comprising a deforming part (41) for using elastic forces as reset force against the flow of liquid.
13. The flow detection device (10, 100) according to any one of claims 1 to 12, wherein the detecting element (3) is configured as an optical detection element comprising a transmitting member (31, 32) and a receiving member (33).
14. The flow detection device (10, 100) according to claim 13, wherein the transmitting member (31) of the optical detection element includes a light barrier beam (31) for sensing the movement of the flow restricting element (2).
15. The flow detection device (10, 100) according to claim 14, wherein the flow restricting element (2) comprises a flag member (21 A) to be sensed by the light barrier beam (31).
16. The flow detection device (10, 100) according to claim 13, wherein the transmitting member (32) of the optical detection element includes at least one light beam (32) and wherein the receiving member (33) of the optical detection element includes a light detector (33).
17. The flow detection device (100) according to claim 13, wherein the flow restricting element (2) is configured to cause a lensing effect to be detected by the optical detection element, when the flow restricting element (2) is moved.
18. The flow detection device (10, 100) according to any one of claims 1 to 12, wherein the detecting element (3) is configured as an electrical detection element.
19. The flow detection device (10, 100) according to claim 18, wherein the electrical detection element (3) is at least partially embedded in the flow restricting element (2).
20. The flow detection device (10, 100) according to claim 19, wherein the electrical detection element (3) comprises at least one conductive part (34) and at least one electrode part (35A, 35B, 36A, 36B) for detecting the capacity, when the flow restricting element (2) is moved.
21. The flow detection device (100) according to claim 18, wherein the electrical detection element (3) is configured as a resistive strain gauge (37A, 37B).
22. The flow detection device (10) according to claim 18, wherein the electrical detection element (3) is configured as a foil piezo element (3 8A) or a piezo resistive foil (38B).
23. A method for qualitative detecting a flow of liquid in a measuring chamber (1) with a flow detection device (10, 100) according to any one of the claims 1 to 22, the method comprising:
inflowing liquid into the measuring chamber (1);
applying a reset force against the flow of liquid by the flow restricting element (2); detecting the movement of the flow restricting element (2) by the detecting element (3); and
-20comparing the detected movement of the flow restricting element (2) with a threshold.
24. A method for quantitative detecting a flow measurement of a liquid in a measuring chamber (1) with a flow detection device (10, 100) according to any one of the claims 17, 18, and 20, the method comprising:
inflowing liquid into the measuring chamber (1);
applying a reset force against the flow of liquid by the flow restricting element (2); detecting the movement of the flow restricting element (2) by the detecting element (3);
assessing the amplitude of the movement of the flow restricting element (2) proportionally to the flow of the liquid; and calibrating the amplitude of the movement the flow restricting element (2).
25. Use of a flow detection device (10) according to any one of the claims 1 to 22 for detecting a flow of liquid in a pipettor for controlling rinsing processes.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB1801408.4A GB2570495A (en) | 2018-01-29 | 2018-01-29 | Flow detection device and method for detecting a flow of liquid |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB1801408.4A GB2570495A (en) | 2018-01-29 | 2018-01-29 | Flow detection device and method for detecting a flow of liquid |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| GB201801408D0 GB201801408D0 (en) | 2018-03-14 |
| GB2570495A true GB2570495A (en) | 2019-07-31 |
Family
ID=61558170
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB1801408.4A Withdrawn GB2570495A (en) | 2018-01-29 | 2018-01-29 | Flow detection device and method for detecting a flow of liquid |
Country Status (1)
| Country | Link |
|---|---|
| GB (1) | GB2570495A (en) |
Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US1967018A (en) * | 1931-12-02 | 1934-07-17 | Wired Radio Inc | Fluid flow indicator |
| US2577564A (en) * | 1946-07-27 | 1951-12-04 | Rca Corp | Fluid flow control system |
| GB921672A (en) * | 1961-04-26 | 1963-03-20 | Mather & Platt Ltd | Improved liquid flow detector |
| DE3044219A1 (en) * | 1980-11-25 | 1982-06-03 | Horst 3412 Nörten-Hardenberg Jungkeit | Fluid flow vol. measuring appts. - has measured value generator with elastically deformable measuring member with elongation measuring strip(s) |
| JPH01307670A (en) * | 1988-06-07 | 1989-12-12 | Mitsubishi Agricult Mach Co Ltd | Flow rate sensor |
| DE3939573A1 (en) * | 1989-11-30 | 1991-06-06 | Baldur Dr Ing Barczewski | Sensor for measuring forces and derivable physical parameters - has light source connected to clamped end of elastically deflectable light conducting body, with position detector at other end |
| JP2000028405A (en) * | 1998-07-10 | 2000-01-28 | Nippon Aleph Corp | Flow rate detector |
| US6358058B1 (en) * | 1998-01-30 | 2002-03-19 | 1263152 Ontario Inc. | Aerosol dispensing inhaler training device |
| US20030066340A1 (en) * | 2001-10-09 | 2003-04-10 | Brian Edward Hassenflug | Conductive fluid leak detection system & automatic shut off valve |
| JP2013117452A (en) * | 2011-12-03 | 2013-06-13 | Waseda Univ | Fluid detector |
-
2018
- 2018-01-29 GB GB1801408.4A patent/GB2570495A/en not_active Withdrawn
Patent Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US1967018A (en) * | 1931-12-02 | 1934-07-17 | Wired Radio Inc | Fluid flow indicator |
| US2577564A (en) * | 1946-07-27 | 1951-12-04 | Rca Corp | Fluid flow control system |
| GB921672A (en) * | 1961-04-26 | 1963-03-20 | Mather & Platt Ltd | Improved liquid flow detector |
| DE3044219A1 (en) * | 1980-11-25 | 1982-06-03 | Horst 3412 Nörten-Hardenberg Jungkeit | Fluid flow vol. measuring appts. - has measured value generator with elastically deformable measuring member with elongation measuring strip(s) |
| JPH01307670A (en) * | 1988-06-07 | 1989-12-12 | Mitsubishi Agricult Mach Co Ltd | Flow rate sensor |
| DE3939573A1 (en) * | 1989-11-30 | 1991-06-06 | Baldur Dr Ing Barczewski | Sensor for measuring forces and derivable physical parameters - has light source connected to clamped end of elastically deflectable light conducting body, with position detector at other end |
| US6358058B1 (en) * | 1998-01-30 | 2002-03-19 | 1263152 Ontario Inc. | Aerosol dispensing inhaler training device |
| JP2000028405A (en) * | 1998-07-10 | 2000-01-28 | Nippon Aleph Corp | Flow rate detector |
| US20030066340A1 (en) * | 2001-10-09 | 2003-04-10 | Brian Edward Hassenflug | Conductive fluid leak detection system & automatic shut off valve |
| JP2013117452A (en) * | 2011-12-03 | 2013-06-13 | Waseda Univ | Fluid detector |
Also Published As
| Publication number | Publication date |
|---|---|
| GB201801408D0 (en) | 2018-03-14 |
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