DE102010030790A1 - Method for measuring e.g. volumetric flow, of liquid inflowing into container in e.g. micro process engineering field, involves determining volume and/or volume flow based on measured gas pressure - Google Patents

Abstract

The method involves providing gas under an initial pressure in a predetermined output volume (V0) in a container (1) before influx of liquid (A, B). The enclosed gas is compressed on the liquid flown into the container from volume of the flowed liquid based on gas volume. A volume flow is made based on increase of a gas pressure (pG) of the gas in the container opposite to output pressure. The gas pressure in the container is measured as function of time. The volume and/or the volume flow are determined based on the measured gas pressure. An independent claim is also included for a device for measuring volumetric flow of liquid inflowing into a container and/or a volume of liquid flowed into the container.

Description

The invention relates to a method for measuring a volume flow of a liquid flowing into a container and / or a volume of liquid flowing into the container, as well as a device for carrying out this method.

The invention can be used in all areas of industrial metrology, medicine and laboratory technology, in which liquids are transported or metered in a controlled manner, in particular with the aid of microfluidic systems or in the field of micro process engineering. This is especially the case in the field of analysis of liquids. Examples include analytical systems for monitoring and optimizing the cleaning performance of sewage treatment plants, for drinking water monitoring, for monitoring biotechnological processes or for monitoring the quality of industrially used liquids or foods. Measured and monitored, for example, the content of a liquid sample of substances, eg. As of ions such as ammonium, phosphate or nitrate, to biological or biochemical compounds, such as. As hormones, or to microorganisms, eg. B. to bacteria.

In such systems, it is necessary in addition to the liquid to be analyzed for their analysis optionally additional required liquids such. B. reagent solutions to dose in predetermined amounts, if necessary, to mix predetermined desired volumes of different liquids, and / or to generate predetermined target volume flows of liquids through lines or measuring and / or analysis units.

In order to be able to achieve the highest possible degree of automation, especially in the field of analysis, devices and methods are required, by means of which, as a rule, very small nominal volumes of less than 50 ml, in particular of less than 10 ml, required in miniaturized systems metered, and by the low flow rates of less than 5000 .mu.L / min, esp. Less than 1000 .mu.L / min, the liquids can be controlled by the individual systems in dependence on the particular process or process predetermined target volume flows.

Peristaltic pumps are used today, for example, for transporting these fluids. However, due to their functional principle, peristaltic pumps usually produce pulsating volume flows. In addition, the elastic tubing used in conjunction with peristaltic pumps is subject to aging, which affects the delivery rate of the peristaltic pumps. This limits the accuracy with which predetermined nominal volumes of a liquid can be filled or predetermined nominal volume flows can be generated.

Another frequently used variant for the transport of fluids are syringe pumps. These are characterized by high accuracy and uniform flow properties. However, the use of syringe pumps in automated systems precludes their high price and their low robustness.

Volume flows can be achieved in a simple manner by pneumatic devices in which liquid flows by pressurizing the liquid provided in a reservoir with a gas, esp. With air, are effected. Typically, however, the flow resistance of these systems changes with time, e.g. B. due to the increasing emptying of the reservoir, so that here a regulation of the volume flow through the system is required.

For this purpose, the flow z. B. by appropriate integrated into the fluid system flow sensors, as for example in the WO 2007/147786 A1 are described, are measured. However, these sensors are expensive and come in direct contact with the liquid.

The latter involves the risk of contamination of both the sensor and the liquid.

It is an object of the invention to provide a device and a method for measuring a volume flow of a liquid flowing into a container and / or a volume of the liquid flowed into the container, with or with the particular in microfluidic systems and esp. In the field A high degree of automation can be achieved in the analysis.

• – vor dem Einströmen der Flüssigkeit in einem vorgegebenen Ausgangsvolumen im Behälter ein Gas unter einem Ausgangsdruck eingeschlossen wird,
• – die anschließend in den Behälter einströmende Flüssigkeit das eingeschlossene Gas auf ein von dem Volumen der eingeströmten Flüssigkeit abhängiges Gasvolumen komprimiert, und einen vom eingeströmten Volumen und vom einströmenden Volumenstrom abhängigen Anstieg des Gasdrucks des Gases im Behälter gegenüber dem Ausgangsdruck bewirkt,
• – der Gasdruck im Behälter als Funktion der Zeit gemessen wird, und
• – das bis zur Zeit eingeströmte Volumen und/oder der zur Zeit einströmende Volumenstrom anhand des gemessenen Gasdrucks bestimmt wird.

For this purpose, the invention comprises a method for measuring a volume flow of a liquid flowing into a container and / or a volume of the liquid which has flowed into the container, in which

• - before the liquid flows in a predetermined initial volume in the container, a gas is trapped under an outlet pressure,
• The liquid subsequently flowing into the container compresses the trapped gas to a gas volume dependent on the volume of the liquid which has flowed in, and causes a rise in the gas pressure of the gas in the container relative to the outlet pressure, dependent on the inflow volume and the inflowing volume flow;
• - The gas pressure in the container is measured as a function of time, and
• - The volume flowed in up to the time and / or the current inflowing volume flow is determined on the basis of the measured gas pressure.

In this case, the volume flowed in up to the time is determined on the basis of the currently measured gas pressure.

To determine the volume flow, a change with time of the measured gas pressure is determined, and the volume flow currently flowing into the container is determined on the basis of the temporal change of the measured gas pressure at the time.

• – ein relativer Gasdruck definiert, der gleich einem Quotienten aus dem Ausgangsdruck und dem Gasdruck ist,
• – eine Kenngröße bestimmt, die die Steigung des relativen Gasdrucks in Abhängigkeit vom eingeströmten Volumen angibt,
• – während des Einströmens der Flüssigkeit in den Behälter anhand des als Funktion der Zeit gemessenen Gasdrucks der relative Gasdruck als Funktion der Zeit bestimmt, und
• – das Volumen und/oder der Volumenstrom werden anhand des relativen Gasdrucks bestimmt.

According to a further training will

• Defines a relative gas pressure which is equal to a quotient of the outlet pressure and the gas pressure,
• A parameter is determined which indicates the slope of the relative gas pressure as a function of the inflow volume,
• - During the flow of liquid into the container on the basis of the measured gas pressure as a function of time, the relative gas pressure determined as a function of time, and
• - The volume and / or the volume flow are determined by the relative gas pressure.

The parameter is preferably determined in an upstream calibration procedure.

• – wird das bis zum Zeitpunkt eingeströmte Volumen als Quotient aus dem um 1 reduzierten relativen Gasdruck zur Zeit und der Kenngröße bestimmt, und/oder
• – es wird eine zeitliche Änderungsrate des relativen Gasdrucks bestimmt, und
• – der zur Zeit einströmende Volumenstrom als Quotient aus der zeitliche Änderungsrate des relativen Gasdrucks und der Kenngröße bestimmt wird.

According to one embodiment of this development

• The volume flowed in up to the point in time is determined as the quotient of the relative gas pressure reduced by 1 at the time and the parameter, and / or
• A time rate of change of the relative gas pressure is determined, and
• - The currently flowing volume flow is determined as a quotient of the time rate of change of the relative gas pressure and the characteristic.

• – einer an den Behälter angeschlossenen Vorrichtung, die dazu dient, Gas in einem vorgegebenen Ausgangsvolumen im Innraum des Behälters vor dem Einströmen der Flüssigkeit unter einem Ausgangsdruck einzuschließen,
• – einem Drucksensor zur Messung des Gasdrucks im Behälter,
• – einer an eine in den Innenraum des Behälter mündende Befüllöffnung des Behälters angeschlossene Flüssigkeitszufuhreinrichtung, die dazu dient dem Behälter Flüssigkeit zuzuführen, und
• – einer elektronischen Einheit,
• – die anhand des nach dem Verschließen des unter dem Ausgangsdruck mit dem Ausgangsvolumen an Gas befüllten Behälters mit dem Drucksensor gemessenen Gasdrucks das Volumen der eingeströmten Flüssigkeit und/oder den Volumenstrom der einströmenden Flüssigkeit bestimmt.

Furthermore, the invention comprises a device for carrying out the method according to the invention, with

• - A device connected to the container, which serves to include gas in a predetermined initial volume in the interior of the container before the inflow of the liquid under an outlet pressure,
• A pressure sensor for measuring the gas pressure in the container,
• - One connected to an opening into the interior of the container filling opening of the container liquid supply means, which serves to supply the container liquid, and
• - an electronic unit,
• - Which determines the volume of the inflowing liquid and / or the volume flow of the inflowing liquid by means of the gas pressure measured after closing the container filled with the starting volume of gas at the outlet pressure with the pressure sensor.

According to a development, the device comprises a controller which controls the liquid supply effected by the liquid supply device as a function of the measured volume flowed into the container or the measured volume flow flowing into the container.

According to one embodiment, the controller terminates the liquid supply when the measured volume reaches a predetermined target volume.

• – das Gas in dem vorgegebenen Ausgangsvolumen unter dem Ausgangsdruck eingeschlossen wird,
• – der Behälter über die Vorrichtung zur Bewirkung des Flüssigkeitsstromes sukzessiv mit vorgegebenen Sollvolumen von Flüssigkeiten aus zwei oder mehr verschiedenen Speichern befüllt wird,
• – wobei das Erreichen der jeweiligen Sollvolumina der einzelnen Flüssigkeiten anhand des gemessenen in den Behälter insgesamt eingeströmten Volumens und dem zu Beginn des jeweiligen Befüllvorgangs mit der jeweiligen Flüssigkeit aus dem jeweiligen Speicher bereits in dem Behälter befindlichen und mit der Vorrichtung gemessenen Volumen überwacht wird.

The invention further comprises a method for operating the device having the control, the liquid supply device of which comprises at least two reservoirs filled with liquid and a device for effecting a flow of liquid from the reservoirs into the reservoir, in which

• The gas is trapped in the predetermined initial volume under the outlet pressure,
• - The container is successively filled via the device for effecting the liquid flow with predetermined target volume of liquids from two or more different memories,
• - Wherein the achievement of the respective target volumes of the individual liquids is monitored by the measured volume flowed into the container and the beginning of the respective filling with the respective liquid from the respective memory already in the container and measured with the device volume.

In this case, during the successive filling of the container with the different nominal volumes of the individual liquids, it is preferable to start filling with the liquid from which the largest nominal volume is required, and then continue the filling successively with the liquid from which the next smaller nominal volume is required becomes.

• – die Flüssigkeitszufuhreinrichtung die Flüssigkeit durch eine Speiseleitung in den Behälter leitet,
• – ein Volumenstrom der Flüssigkeit durch die Speiseleitung gleich dem in den Behälter einströmenden Volumenstrom ist, und
• – eine Regeleinrichtung vorgesehen ist, die die durch die Flüssigkeitszufuhreinrichtung bewirkte Flüssigkeitszufuhr anhand des gemessenen in den Behälters einströmenden Volumenstroms derart regelt, dass der Volumenstrom durch die Speiseleitung und der Volumenstrom in den Behälter einem vorgegebenen Sollvolumenstrom entspricht.

Furthermore, the invention comprises a development of the device according to the invention, in which

• The liquid supply device passes the liquid through a feed line into the container,
• A volume flow of the liquid through the feed line is equal to the volume flow entering the container, and
• - A control device is provided which controls the liquid supplied by the liquid supply means based on the measured volume flow flowing into the container such that the volume flow through the feed line and the volume flow into the container corresponds to a predetermined nominal volume flow.

• – ist in die Speiseleitung eine Mess- oder Analyseeinrichtung eingesetzt,
• – ist ein Volumenstrom der Flüssigkeit durch die Mess- oder Analyseeinrichtung gleich dem Volumenstrom durch die Speiseleitung und gleich dem in den Behälter einströmenden Volumenstrom, und
• – die Regeleinrichtung regelt den Volumenstrom durch die Mess- oder Analyseeinrichtung anhand des gemessenen in den Behälters einströmenden Volumenstroms auf einen vorgegebenen Sollvolumenstrom.

According to a preferred embodiment

• - a measuring or analyzing device is inserted in the feed line,
• - Is a volume flow of the liquid through the measuring or analysis device equal to the flow rate through the feed line and equal to the inflowing into the tank volume flow, and
• - The control device controls the volume flow through the measuring or analysis device based on the measured flow into the tank volume flow to a predetermined nominal volume flow.

• – die Flüssigkeitszufuhreinrichtung mindestens einen mit Flüssigkeit gefüllten Speicher und eine Vorrichtung zur Bewirkung eines Flüssigkeitsstromes von mindestens einem der Speicher in den Behälter umfasst,
• – die Vorrichtung zur Bewirkung des Flüssigkeitsstromes einen regelbaren pneumatischen Druckgeber umfasst,
• – der jeweils über eine mit einem steuerbaren Ventil, insb. einem 3/2 Wege Umschaltventil, versehene Druckzuleitung an die Speicher angeschlossen ist, und
• – der Flüssigkeitsstrom durch eine Druckbeaufschlagung der Flüssigkeit in den Speichern mit einem von dem regelbaren pneumatischen Druckgeber erzeugten Druck bewirkt wird.

Furthermore, the invention comprises a development of the device according to the invention, in which

• The liquid supply device comprises at least one liquid-filled reservoir and a device for effecting a flow of liquid from at least one of the reservoirs into the reservoir,
• The device for effecting the liquid flow comprises a controllable pneumatic pressure transmitter,
• - Which is connected in each case via a with a controllable valve, esp. A 3/2-way changeover valve, provided pressure supply to the memory, and
• - The liquid flow is effected by pressurizing the liquid in the reservoirs with a pressure generated by the controllable pneumatic pressure transducer.

According to a first development of the last-mentioned further development, the controllable pneumatic pressure transmitter is connected to the container via a pressure supply line which can be closed by a controllable valve, in particular a 3/2 way changeover valve.

According to a preferred development, the liquid supply device is connected to the container via at least one supply line equipped with a valve, in particular a check valve.

• – der Behälter und die Flüssigkeit in den Speichern vorab über die 3/2 Wege Umschaltventile mit dem Ausgangsdruck beaufschlagt werden,
• – das Ventil in der vom Druckgeber zum Behälter führenden Druckzuleitung geschlossen wird,
• – durch Druckbeaufschlagung von Flüssigkeit aus mindestens einem der Speicher mit einem von dem Druckgeber erzeugten Druck ein Flüssigkeitsstrom in den Behälter bewirkt wird, und
• – abschließend die insgesamt in dem jeweiligen Betriebszyklus in den Behälter eingeströmte Flüssigkeit, insb. durch Druckbeaufschlagung, aus dem Behälter abgeführt wird.

Furthermore, the invention comprises a method for operating a device according to the three last-mentioned further developments, in which operating cycles are carried out, in each of which

• - the reservoir and the liquid in the reservoirs are pre-pressurized with the outlet pressure via the 3/2 way change-over valves,
• The valve is closed in the pressure feed line leading from the pressure transducer to the container,
• - By pressurizing liquid from at least one of the memory with a pressure generated by the pressure transducer, a liquid flow is effected in the container, and
• - Finally, the total flowed into the container in the respective operating cycle liquid, esp. By pressurization, is discharged from the container.

According to a further development of the first further development of the device, the container is connected via a discharge line equipped with a valve, in particular a check valve, to a receiving vessel charged with ambient pressure via a vent opening, into which liquid can be removed.

• – die Flüssigkeitszufuhr in den Behälter unterbrochen wird, und
• – die im Behälter enthaltene Flüssigkeit über den Druckgeber mit einem Druck beaufschlagt wird, bei dem die Flüssigkeit durch das Rückschlagventil hindurch über die Ablassleitung ausströmt.

Furthermore, the invention comprises a method for operating a device according to the last-mentioned further development, in which the liquid is discharged from the container at the end of a filling cycle by

• - the liquid supply to the container is interrupted, and
• - The liquid contained in the container is acted upon by the pressure transducer with a pressure at which the liquid flows through the check valve through the drain line.

• – Gas in dem vorgegebenen Ausgangsvolumen unter dem Ausgangsdruck eingeschlossen wird,
• – ein Flüssigkeitsstrom in den Behälter bewirkt wird und der einströmende Volumenstrom und/oder das eingeströmte Volumen gemessen wird,
• – die Flüssigkeitszufuhr in den Behälter unterbrochen wird, bevor der Gasdruck im Behälter einen vorgegebenen Maximaldruck übersteigt, und
• – abschließend die in den Behälter in dem jeweiligen Befüllzyklus insgesamt eingeströmte Flüssigkeit aus dem Behälter abgeführt wird.

Furthermore, the invention comprises a method for operating devices according to the invention, in which operating cycles are carried out, in which case in each case

• Gas is trapped in the given initial volume under the outlet pressure,
• A liquid flow into the container is effected and the inflowing volume flow and / or the inflow volume is measured,
• - The liquid supply to the container is interrupted before the gas pressure in the container exceeds a predetermined maximum pressure, and
• - Finally, the total flowed into the container in the respective filling cycle liquid is discharged from the container.

The invention has the advantage that the device can be operated fully automatically. Another advantage is that the measurements are made indirectly based on the gas pressure in the container, so that this no direct contact, esp. No direct contact of sensors, the liquid is required. In addition, the invention offers the advantage that the measurement due to the indirect measuring method on which the invention is based largely independent of the type of liquids used, esp. Of their viscosities, their inhomogeneities and any contaminants contained therein is. This is in particular an advantage over calorimetric flow measuring methods, in which the measuring accuracy depends significantly on the possibly variable heat capacities of the liquids.

The devices according to the invention offer the advantage that they are extremely versatile. They can be used to replace dosing syringes, syringe pumps, peristaltic pumps as well as systems that pneumatically generate volume flows and regulate them to predetermined set volume flows using direct flow measurements with flow sensors in the flow path.

The invention and further advantages will now be explained in more detail with reference to the figures of the drawing, in which two embodiments are shown. Identical elements are provided in the figures with the same reference numerals.

1 shows: a device according to the invention; and

2 shows: a section of an alternative embodiment.

1 shows an inventive device for measuring a volume flow dV (t) / dt one into a container 1 inflowing liquid and / or one into the container 1 inflow volume V (t) of the liquid.

The device comprises a to an in the interior of the container 1 opening filling opening 3 of the container 1 connected liquid supply device 5 that serves to the container 1 To supply liquid. This comprises at least one filled with a liquid A, B memory 7 . 9 is provided in the liquid. The stores 7 . 9 For example, storage tanks containing individual liquids to be analyzed or additional liquids required for analysis, such. For example, reagent solutions. The liquids A, B can in the stores 7 . 9 for example, in a flexible gas and liquid impermeable container, e.g. As a bag made of a plastic film, such as polyethylene or polypropylene, may be included. The stores 7 . 9 are preferably designed as exchangeable modules. The memory can 7 . 9 be provided as individual elements, or it can be combined parallel to each other in a preferably exchangeable storage cartridge two or more memory.

The stores 7 . 9 are to a device for effecting a liquid flow of at least one of the memory 7 . 9 in the container 1 connected. This device comprises a controllable pneumatic pressure transducer 11 , which in each case via a pressure supply line closable with a controllable valve V1, V2 13 . 15 on the input side to the memory 7 . 9 connected. The valves V1, V2 are preferably 3/2 way switching valves, via which the memory 7 . 9 optionally with that of the pressure transducer 11 generated pressure p or a reference pressure p _B , preferably the atmospheric pressure, can be acted upon, or pressure-tight and gas-tight closure by closing the respective valve V1, V2 on the input side. The terms 'open' and 'close' are used here in conjunction with all valves throughout such that the associated line in which the respective valve is inserted, with the valve open and locked when the valve is closed.

On the output side are the memories 7 . 9 each via a supply line 17 . 19 to the filling opening 3 of the container 1 connected, in which the container 1 each end facing a valve VR1, VR2, preferably a check valve is used. The two supply lines 17 . 19 open in the illustrated embodiment in a supply line 20 They with the container opening 3 combines.

Is only a memory, for. B. the memory 7 is provided, preferably a single immediately before the filling opening 3 in that case from the store 7 to the container opening 3 leading supply line 20 used - in 1 additionally marked - valve VR used. In that case, the in 1 illustrated second memory 9 whose supply line 19 and the two valves VR1 and VR2.

The same applies to several always simultaneously used parallel to the filling memory, their liquids in a directly to the container 1 leading supply line 20 be merged. The latter corresponds to the illustrated variant without the two valves VR1 and VR2 in the supply lines 17 and 19 ,

On the other hand, there are two or more memories 7 . 9 in each case via their supply line equipped with the respectively associated valve VR1, VR2 17 . 19 z. B. over the further supply line 20 to the container 1 connected, so the valve VR shown here can be omitted.

Alternatively, the container 1 for each of the supply lines connected to one of the memory have their own filling, to which the supply lines are each connected via a valve. This embodiment is in the in 2 illustrated section of an alternative embodiment a device according to the invention shown. There are four stores 7a . 7b . 7c . 7d each via a connected supply line 17a . 17b . 17c . 17d to one of the four filling openings 3a . 3b . 3c . 3d of the container 1 connected. Each of the four supply lines 17a . 17b . 17c . 17d is on the tank side with a valve VRa, VRb, VRc, VRd, preferably a passive check valve equipped.

A liquid stream from one or more times in succession from several stores 7 . 9 in the container 1 , at the in 1 illustrated variant now at any time be effected by the liquid in the respective memory 7 . 9 via the pressure transducer 11 is subjected to a pressure p far enough above that inside the container 1 prevailing pressure is the breakthrough pressure of the respective check valve VR1, VR2 or VR and the flow resistance of the respective supply line 17 . 19 and 20 to overcome. As soon as the pressure dropping over the respective check valve VR1, VR2 or VR is greater than its breakthrough pressure, a liquid flow flows out of the respective store 7 respectively. 9 in the container 1 that increasing with, from the pressure transducer 11 generated pressure p increases. Via a corresponding control of the pressure transmitter 11 and the valves V1, V2, the liquid supply can be fully automatic. This is the container 1 depending on the measuring method according to the invention and the use of the device at predetermined times, liquid A, B from a selected memory, from a plurality of selected memories, or from all memories 7 . 9 supplied, or the total fluid supply interrupted.

To remove fluid from one or more stores 7 . 9 To interrupt, the liquid A, B in the affected stores 7 . 9 preferably via a corresponding control of the respective 3/2 way switching valve V1, V2 in the associated pressure supply line 13 . 15 with the reference pressure p _B , in particular the atmospheric pressure, applied. This ensures that the pressure drop across the respective non-return valve VR1, VR2 or VR drops immediately below the breakthrough pressure, and no liquid A, B more through the respective supply line 17 . 19 respectively. 20 can escape. Alternatively, when active valves are used instead of the passive check valves VR1, VR2, the liquid supply can also be controlled by actively opening and closing these valves. However, this must be in the memories 7 . 9 also a sufficient overpressure relative to the volume of the container 1 prevail in order to generate a volume flow of the liquid when the active valve is open.

In the same way, the liquid supply from the individual stores 7a . 7b . 7c . 7d the in 2 shown variant, the corresponding thereto in each case via a with a 3/2 way switching valve Va, Vb, Vc, Vd equipped pressure supply line 13a . 13b . 13c . 13d to the pressure transmitter 11 are connected.

Unlike the in 1 illustrated variant in which all memory 7 . 9 are in advance filled with liquid reservoir is in 2 an example of a memory, the memory 7a formed as a sampler, which within the inventive device in an upstream filling with a liquid S, z. B. a sample to be analyzed, can be charged. For this purpose, this memory 7a a sample supply line LS, which opens in the interior of the storage space and has a valve VS1, preferably a check valve, and the storage interior is provided with an intermediate storage 7a and valve Va in the pressure supply line 13a connected with a valve V _V equipped branch L _{V connected} to a vacuum pump P _V. By applying a vacuum to the storage interior, the liquid S can now be transferred to the storage via the sample supply line LS 7a be sucked. Meanwhile, the level in the storage interior is preferably monitored by a corresponding - shown here by two electrodes E1, E2 - sensor. To during the filling process, an entry of liquid over the container 1 leading supply line 17a To prevent is in the with the supply line 17a connected output of the memory 7a another valve VS2, preferably also a check valve provided.

Apart from the special nature of the sampling, the following statements apply to the in 1 illustrated accordingly also for the embodiment of 2 ,

The container 1 has in its interior a predetermined initial volume V ₀ , which contains no liquid at the beginning of each operating cycle of the device. Any drops or residual moisture still adhering to the inner walls are considered to be negligible due to their extremely low influence on the process according to the invention. To the container 1 a device is connected, which serves in the predetermined output volume V ₀ before the influx of liquid gas, esp. Air, include at an output pressure p ₀ .

Preferably, the already existing controllable pneumatic pressure transducer 11 via a further with a valve V3, preferably a 3/2 way switching valve, ausgestalt Druckzuleitung 21 to the container 1 connected. The output pressure p ₀ can be a from the pressure transducer 11 be generated pressure with which the container 1 via the pressure supply line 21 is charged. Preferably, however, as the output pressure p _{0 of} the above Reference pressure p _B , that is, preferably the atmospheric pressure used with which the container 1 is acted upon by a corresponding control of the 3/2 way switching valve V3. This way in the container 1 Gas in the initial volume V ₀ is then trapped by the vessel 1 is closed gas-tight and pressure-tight by the complete closure of the valve V3. After this, the output pressure p ₀ prevails inside the now closed system.

Alternatively, the initial volume V ₀ via a ventilation opening not shown in the container 1 filled with air under atmospheric pressure, and then sealed gas-tight by means of a suitable closure.

In order to predetermine the initial volume V ₀ in a reproducible manner, a defined initial state of the device is preferably effected in advance, in which the supply lines 17 . 19 respectively. 20 are filled to the respective valve located therein VR1, VR2 or VR with liquid A, B. The reproducible predetermined output volume V ₀ now includes the not filled with liquid remaining line volume of the leads 17 . 19 respectively. 20 between the respective valve VR1, VR2 or VR and the container opening 3 , the internal volume of the container 1 and the line volume in the interior of the pressure feed line 21 from the container 1 to the valve V3.

To the container 1 is a pressure sensor 23 connected, with a gas pressure p _G inside the container 1 is measured. If the pressure sensor 23 not directly inside the container 1 is arranged, so also forms the inner volume of the connecting cable 22 via which the gas pressure p _G the pressure sensor 23 is supplied, a component of the output volume V ₀ .

In a first method step, as already explained above, the gas is enclosed in the initial volume V ₀ at the outlet pressure p ₀ . Preferably, the liquids in the stores 7 . 9 during the pressurization of the output volume V ₀ with the output pressure p _{0 in} parallel to that in the pressure supply lines thereof 13 . 15 used 3/2 way switching valves V1, V2 also acted upon by gas at the output pressure p ₀ . As a result, a defined starting situation is created in which there is no pressure drop across the check valves VR1, VR2 or VR. The check valves VR1, VR2 and VR prevent in this process step the penetration of liquid into the container 1 ,

In the next process step, the container filled with gas under the initial pressure p ₀ is 1 closed gas-tight by the complete closing of the valve V3, and the outlet pressure p ₀ in the container 1 with the pressure sensor 23 measured.

Subsequently, a liquid flow of one or more memories 7 . 9 in the container 1 causes. For this purpose, that of the pressure transducer 11 generated pressure p over the pressure supply lines 13 . 15 by a corresponding control of the valves V1, V2 exclusively the memories 7 . 9 fed, the liquid to spend. To effect the flow of liquid into the container 1 becomes the pressure p of the pressure transducer 11 increased to a pressure p far enough above that inside the container 1 prevailing pressure is the breakthrough pressure of the respective check valve VR1, VR2 or VR and the flow resistance of the respective supply line 17 . 19 and the supply line 20 to overcome. In this case, the higher the pressure p, the greater the liquid flow.

The in the container 1 inflowing liquid compresses this in the container 1 enclosed gas to a dependent on the total volume V (t) of the liquid-dependent liquid volume V _G , which is approximately equal to the difference between the initial volume V ₀ and the volume V (t) of the total up to the respective time t flowed liquid. Minor, usually negligible, deviations from this difference are due to the compressibility of the respective liquid and the solubility of the gas in the respective liquid. The inflowing liquid thereby causes a rise of the gas pressure p _G (t) of the gas in the container, which is dependent on the inflowing volume V (t) and on the inflowing volume flow dV (t) / dt 1 relative to the outlet pressure p ₀ .

According to the invention, the gas pressure p _G (t) of the gas in the container 1 measured as a function of time t, and the measured gas pressure p _G (t) into the container 1 up to the time t total volume flowed V (t) and / or into the container 1 at time t inflowing volume flow dV (t) / dt determined.

Assuming that the trapped gas behaves like an ideal gas, the Boyle-Mariotte law applies, according to which the product of gas pressure p _G and gas volume V _{G of} the trapped gas is constant at constant temperature, and thus equal to the product of outlet pressure p ₀ and initial volume V ₀ . Thus, approximately: p ₀ V _G = p _G (V ₀ -V) = p ₀ V ₀

und der zur Zeit t einströmende Volumenstrom dV(t)/dt zu:

Based on this relationship, the volume V (t) of the liquid which has flowed up until time t results in:

and the volume flow dV (t) / dt flowing in at time t:

Both quantities can be calculated directly from the gas pressure p _G (t) measured as a function of the time t.

For this purpose, the device comprises a to the pressure sensor 23 connected electronic unit 25 , Based on the after filling the under output pressure p ₀ filled with the initial volume V ₀ to gas tank 1 with the pressure sensor 23 as a function of the time t measured gas pressure p _G (t) during each operating cycle determines the inflow volume V (t) and / or the inflowing volume flow dV (t) / dt of the liquid.

Since it may be very difficult or expensive, the initial volume V ₀ in the container 1 to determine exactly and the behavior of the gas, eg. B. due to moisture contained therein, slightly different from that of an ideal gas, a calibration method is preferably carried out in advance.

For this purpose, a relative gas pressure p _{R is} defined which is equal to a quotient of the output pressure p ₀ and the measured gas pressure p _G.

In the upstream calibration method, starting from the defined initial state described above with the gas enclosed in the initial volume V ₀ at the outlet pressure p ₀ , a parameter m _{V of} the device is determined which indicates the slope of the relative gas pressure p _R as a function of the inflow volume V.

This change in the relative gas pressure p _R per change in the inflow volume V can be determined, for example, in which the container 1 successively filled with several known reference volume, and based on the thereby measured gas pressures p _G, the associated relative gas pressures p _R as a function of each in the container 1 be recorded liquid volume. Alternatively, the parameter m _V can be determined by the container 1 is filled with a constant known reference volume flow of liquid, from which the inflow volume V is derived by integration over time, and the associated relative gas pressures p _{R are recorded} as a function of the inflow volume V on the basis of the measured gas pressures p _G. in both cases, the slope of the recorded relative gas pressures p _R as a function of the volume V flowed in reproducing characteristic curve is determined, which is equal to the sought characteristic m _V.

The parameter m _V is a constant which essentially corresponds to the negative reciprocal of the output volume V ₀ , and at the same time takes into account deviations of the behavior of the gas from that of an ideal gas.

verwendet werden.When such a calibration method can not be executed or will, it may - if known, or by measuring certain initial volume V ₀ - for the further method described below instead of the parameter m _V m, an approximate value _V ', comprising:

be used.

Following the calibration procedure, the liquid is removed from the container 1 emptied and the defined initial state restored.

The subsequent operation of the device is preferably carried out in successive operating cycles in which, starting from the initial state, gas is included under the initial pressure p ₀ in the initial volume V ₀ , the container 1 is then filled with liquid, and finally the total in the respective operating cycle in the container 1 inflowing liquid from the container 1 is dissipated.

During the filling process, the volume V (t) which has flowed in at the time t is determined as the quotient of the relative gas pressure p _R (t) reduced by 1 and the parameter m _V. D. h .:

During the filling process, a time change rate dp _R / dt of the relative gas pressure p _{R is} determined on the basis of the gas pressure p _G (t) measured as a function of time, and the volume flow dV (t) / dt of the inflowing liquid to be measured equals a quotient of the rate of change dp _R / dt of the relative gas pressure p _R and the parameter m _V set.

The total in the container 1 Alternatively, volumes V (t) that have flowed up to time t can also be determined by an integration or summation of the volume flows dV (t) / dt measured in the last-mentioned manner over this period of time.

Preferably, all components surrounding the volume V _{0 have} approximately the same temperature, which is preferably at least approximately equal to the temperature of the gas enclosed in the volume V ₀ . Local temperature changes within the volume V ₀ , z. B. by heating the valve V3, should be avoided if possible, as this pressure changes can be effected, which lead to a temperature-dependent measurement inaccuracy. A predominantly by a homogeneous temperature change of the enclosed volume V ₀ caused gas pressure change can using an integrated in the volume V ₀ temperature sensor, z. B. on the basis of the equation of state of ideal gases following linear temperature dependence of the product of gas pressure p _G and gas volume V _G , be compensated.

The filling of the container 1 and the measurement of inflow volume V and / or inflowing volume flow dV / dt can now continue until the gas pressure p _G in the container 1 reaches a predetermined maximum pressure P _Gmax . This maximum pressure is due to various physical variables, such as the liquid holding capacity of the container 1 , the pressure resistance of the supply lines 17 . 19 respectively. 20 and the container 1 and the maximum pressure of pressure transducer 11 or pressure sensor 23 specified. However, the maximum pressure P _{Gmax is preferably} to a pressure of less than 2 bar, z. B. to a pressure of 1 bar, set to atmosphere. This prevents the gas from dissolving to a significant degree in the liquid, which could otherwise lead to a deterioration of the measurement accuracy. If the use of the device requires this, the filling can, of course, also prior to reaching the maximum _volume V _max corresponding to the maximum pressure p _{Gmax of} liquid in the container 1 to be ended.

Following the filling process, the in the container 1 located liquid from the container 1 dissipated.

For this purpose, the container 1 via a drain line equipped with a drain valve V _A 27 to a receptacle 29 connected, in which the in the container 1 located liquid can be removed. Again, preferably a modular design is chosen.

The receptacle 29 is preferably with a vent 31 provided, via whose interior is subjected to the ambient pressure.

The bleed valve V _A is preferably also a passive check valve having a breakthrough pressure that is greater than the difference between the maximum gas pressure p _Gmax and the ambient pressure. This ensures that the drain valve V _A , the drain line 27 locks during the filling process.

For removing the liquid from the container 1 the fluid supply is in the container 1 - as already described above - interrupted. Subsequently, the valve V3 is opened and in the container 1 contained liquid via the pressure transducer 11 subjected to a pressure p, wherein the liquid through the check valve V _A through the drain line 27 flows. Ie. the pressure p must be large enough to the breakthrough pressure of the check valve V _A and the line resistance of the drain line 27 to overcome. This pressurization causes the opening of the check valve V _A and the outflow of the liquid into the receptacle 29 ,

After emptying the container 1 is the device back in the initial state and it can immediately be carried out the next cycle of operation in the manner described above.

Preferably, the device comprises one to the pressure sensor 23 connected control 33 , which following the calibration procedure on the basis of the measured gas pressure p _G by a corresponding control of the pressure transducer 11 , the valves V1, V2 and the valve V3 causes a fully automatic operation of the device according to the invention. The control 33 is, for example, an integral part of the electronic unit 25 ,

The device according to the invention can be used or operated in a variety of ways.

A first use is to operate the device as an automated microsyringe for dosing liquids that for example, at predetermined times predetermined target volumes of individual liquids outputs.

The controller controls this 33 the fluid supply effected by the device for effecting the fluid flow from at least one selected reservoir 7 . 9 depending on the measured in the container 1 flowed volume V (t), and terminates the liquid supply by closing the valves V1, V2, when the measured volume V (t) reaches the respective predetermined target volume. It is specified on the control of the valves V1, V2, from which memory 7 . 9 or which store 7 . 9 the container 1 is filled with liquid until reaching the respective desired volume in the respective operating cycle.

So can in the container 1 For example, first a target volume V _{SA of} the liquid A from the memory 7 be measured that then via the drainage line 27 is issued. Subsequently, a target volume V _{SB of} the liquid B from the memory 9 be measured that then via the drainage line 27 is issued. Likewise, by a parallel filling of the container 1 with fluid A and B from both stores 7 . 9 a set volume V _{SAB be} measured and subsequently issued that contains both liquids A and B.

In addition, the device is capable of metering and dispensing a target volume of a liquid, two or more different, in a corresponding number of stores 7 . 9 provided. Contains liquids A, B, in a predetermined mixing ratio. For this purpose, the container 1 within a single operating cycle via a corresponding control of the device for effecting the liquid flow successively filled with the predetermined target volumes V _SA , V _{SB of} the individual liquids A, B from the individual memories A, B, wherein the achievement of the respective target volumes V _SA , V _SB based on the measured in the container 1 Total flowed volume V (t) and the beginning of the filling with the respective liquid A, B from the respective memory 7 . 9 already in the container 1 monitored measured with the device inflow volume V is monitored.

During the successive filling of the container 1 with the different nominal volumes V _SA , V _{SB of} the individual liquids A, B is preferably started with the filling of the liquid A, B, of which the largest target volume V _SA , V _{SB is} required, and then the filling successively with the liquid A, B continued, of which the next smaller target volume V _SA , V _{SB is} needed. This offers the advantage of a relative relative to the respective target volume V _SA , V _SB lower relative, by the measurement accuracy of the pressure sensor 23 conditional, measurement error.

By an extension of in 1 The apparatus shown for effecting the liquid flow to more connected in the same way, filled with other liquids storage, the number of different mixable in predetermined mixing ratios and dosable liquids can be increased to three or more. Alternatively, a modular design can also be selected here, which enables a preferably also automated exchange of individual memories.

In addition, the container can 1 used as a mixing container, which after its filling with the individual target volume V _SA , V _SB, etc. as a memory, in the sense of the memory described here 7 . 9 , is available in a more complex device.

Another use of the device according to the invention is the generation of controlled volume flows of adjustable size.

It will be in the container 1 inflowing volume flow dV / dt on the basis of the measured inflowing volume flow dV / dt by a corresponding control of the liquid supply into the container 1 regulated to a predetermined setpoint. For this purpose, one is preferably also in the electronic unit 25 integrated, to the controller 33 connected control device 35 provided the fluid supply via the control of the pressure transducer 11 and the valves V1, V2 controls accordingly.

In this use, the container becomes 1 filled through a single feed line SP, through which the entire into the container 1 inflowing liquid flows. The volume flow flowing through this feed line SP is therefore equal to that in the container 1 inflowing volume flow dV / dt and is also controlled according to the set flow rate.

The feed line SP here comprises the output side connected to the device for generating the liquid flow supply line 20 through which the total in the container 1 inflowing liquid flows.

In the in 1 shown device can by appropriate control of the liquid supply either one of the leads 17 . 19 operated as part SP17, SP19 of the feed line SP. For this purpose, the container 1 by a corresponding control of the valves V1, V2 in the to the memories 7 . 9 leading pressure supply lines 13 . 15 exclusively with liquid from one of the stores 7 . 9 filled so that during its total in the container 1 inflowing liquid through the respective supply line 17 respectively. 19 flows.

Likewise, of course, analogously to the illustrated device constructed devices may be used, in which some selected memory output side in a feed line, then in this mode of operation, the entire liquid supply into the container 1 he follows. In this variant too, the supply of liquid from all other stores which are not connected to the feed line is prevented by the closure of the associated valves in the associated pressure feed lines.

The automated generation of preset desired volume flows through the feed line SP is esp. In the measurement and / or monitoring of chemical and / or physical properties of the liquid flowing through the feed line SP and in the analysis of this liquid of great advantage.

In this way, by means of the device during the associated Befüllvorgangs a by an inserted into the feed line SP measuring and / or analysis device 37 flowing volume flow to a predetermined for the measurement and / or analysis optimal target volume flow can be controlled.

Instead of or in addition to the in - here by the supply line 20 formed - feed line SP used measuring and / or analysis unit 37 can in the over the store 7 fed supply line 17 and / or in the over the store 9 fed supply line 19 to the container 1 another measuring and / or analyzing device 37a . 37b be used.

While the container 1 only with liquid A from the store 7 is filled, the total flows into the container 1 inflowing volume flow dV / dt through the supply line 17 which thereby becomes part SP17 of the feeder SP. Accordingly, the volume flow through the measuring and / or analyzing device 37a be regulated in this case on the basis of the measured volume flow dV / dt to a predetermined nominal volume flow.

While the container 1 only with liquid B from the store 9 is filled, the total flows into the container 1 inflowing volume flow dV / dt through the supply line 19 which thereby becomes part SP19 of the feeder SP. Accordingly, the volume flow through the measuring and / or analyzing device 37b also be regulated in this case on the basis of the measured volume flow dV / dt to a predetermined nominal volume flow.

Will the container 1 - As mentioned above - used as a mixing vessel, which after its filling with individual target volume V _SA , V _SB, etc. as a memory, in the sense of the memory described here 7 . 9 , is used in a more complex device, so can the drain line 27 be operated as a feed line in the sense described above, and the volume flow through a in the drain line 27 used - not shown here - measuring and / or analyzing device are regulated. In addition, it is of course always possible in the drainage line 27 to use such measuring and / or analysis devices that are functional even without a control of the flow through them volumetric flow.

The device according to the invention is thus extremely versatile.

The simplest use is in the pure measurement of the inflow volume V (t) and / or the inflowing volume flow dV (t) / dt in the container 1 ,

In addition - as described above - predetermined target volumes V _{SA ,} V _{SB can be} measured and output individually or in predetermined mixing ratios. This is needed esp. In chemical and biochemical analysis in homogeneous liquid phase.

In addition, with the device desired volume flows through the feed line SP, SP17 or SP19 can be adjusted. This property is esp. In the surface-bound chemical and biochemical. Analytics, eg As for the operation of an automated immunoassay required.

It is readily possible, the same device in an operating cycle or in successive operating cycles both for generating a desired volume flow through one of the measuring and / or analysis devices 37 . 37a . 37b as well as the highly accurate dosage of predetermined target volume of individual liquids or more in a given mixing ratios to be mixed liquids of the individual in the memory 7 . 9 provided liquids A, B to use.

So can the container 1 for example, first under compliance a predetermined nominal volume flow through the in the supply line 17 used measuring and / or analysis device 37a be filled with a predetermined target volume V _{SA of} the liquid A, then while maintaining a predetermined nominal volume flow through the in the supply line 19 used measuring and / or analysis device 37b be filled with a predetermined target volume V _{SB of} the liquid B, and finally in the container 1 in which by the two desired volumes V _SA and V _SA predetermined mixing ratio of the liquids A and B composite liquid are output.

The devices according to the invention offer the advantage that they can be used to carry out doses and volume flow controls in almost any desired manner one behind the other and / or in combination with one another. Consequently, with the device according to the invention, extremely complex processes and methods can be carried out fully automatically.

The modular design offers the advantage that on the preferably automated exchange of storage 7 . 9 and / or receptacles 25 There is a high degree of flexibility and virtually any number of different liquids A, B can be processed.

Ideally, all liquid-containing and all liquid-carrying components, ie the memory, are thereby used 7 . 9 , the container 1 , the receptacles 29 , and the supply lines 17 . 19 . 20 designed as module modules that are assembled to form an assembly.

Likewise, all other mechanical, pneumatic and electronic components, so the pressure transducer 11 , the electronic unit 25 , the pressure sensor 23 and the pressure feeders 13 . 15 . 21 . 22 and the valves V1, V2, V3 contained therein, preferably combined into one unit. This unit can now be used in conjunction with different assemblies, wherein the connection of the unit to the respective assembly in a simple manner via advantageously equipped with liquid-impermeable gas-permeable membranes or filters pneumatic connections 39 . 41 . 43 he follows. A pneumatic interface is also in the filed on 25.03.2010 German Patent Application of the Applicant with the application number 10 2010 00 33 04.9 described.

LIST OF REFERENCE NUMBERS

1

container

3

filling

5

Liquid supply means

7

Storage

9

Storage

11

adjustable pneumatic pressure transmitter

13

pressure supply line

15

pressure supply line

17

supply

19

supply

21

pressure supply line

23

pressure sensor

25

electronic unit

27

drain line

29

receptacle

31

vent

33

control

35

control device

37

Measuring and / or analyzing device

39

pneumatic connection

41

pneumatic connection

43

pneumatic connection

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• WO 2007/147786 A1 [0008]
• DE 102010003304 [0112]

Claims (20)

Method for measuring a volume flow (dV (t) / dt) into a container ( 1 ) inflowing liquid (A, B) and / or into the container ( 1 ) inflow volume (V (t)) of the liquid (A, B), wherein - before the inflow of the liquid (A, B) in a predetermined initial volume (V ₀ ) in the container ( 1 ) a gas is trapped under an initial pressure (p ₀ ), which is subsequently introduced into the container ( 1 inflowing liquid (A, B) compresses the trapped gas to a volume of gas dependent on the volume (V (t)) of the inflowing liquid, and one of inflowing volume (V (t)) and inflowing volume flow (dV (t) / dt) dependent increase of the gas pressure (p _G ) of the gas in the container ( 1 ) (Caused p _0), - the gas pressure (p _G) in the container as a function of time (t) is measured, and - until the time (t) has flowed volume (V (t) compared to the initial pressure), and / or at the time (t) incoming volumetric flow (dV (t) / dt) on the basis of the measured gas pressure (p _G (t)) is determined. Method according to Claim 1, in which the volume (V (t)) which has flowed in until the time (t) is determined on the basis of the gas pressure (p _G (t)) measured at the time (t). Method according to claim 1, in which - a temporal change of the measured gas pressure (p _G ) is determined, and - the time (t) in the container ( 1 ) inflowing volume flow (dV (t) / dt) is determined on the basis of the temporal change of the measured gas pressure (p _G ) at the time (t). Method according to claim 1, in which - a relative gas pressure (P _R ) is defined which is equal to a quotient of the outlet pressure (p ₀ ) and the gas pressure (p _G ), - a parameter (m _V , m ' _V ) determined is, which indicates the slope of the relative gas pressure (p _R ) in dependence on the inflow volume (V (t)), - during the inflow of liquid into the container ( 1 ) the relative gas pressure (p _R ) is determined as a function of time (t) on the basis of the gas pressure (p _G ) measured as a function of the time (t), - the volume (V (t)) and / or the volume flow (dV ( t) / dt) are determined on the basis of the relative gas pressure (p _R ). Method according to Claim 4, in which the parameter (m _V ) is determined in an upstream calibration method. Method according to Claim 4 or 5, in which the volume (V (t)) which has flowed in up to the time (t) is calculated as the quotient of the relative gas pressure (p _R ) reduced by 1 at the time (t) and the parameter (m _V , m ' _V ) is determined, and / or - a time rate of change of the relative gas pressure (dp _R (t) / dt) is determined, and - at the time (t) inflowing volume flow (dV (t) / dt) as a quotient of Time rate of change of the relative gas pressure (dp _R (t) / dt) and the characteristic (m _V , m ' _V ) is determined. Device for carrying out a method according to one of the preceding claims, with - one to the container ( 1 ), which serves gas in a predetermined initial volume (V ₀ ) in the interior of the container ( 1 ) before the liquid flows in at an outlet pressure (p ₀ ), - a pressure sensor ( 23 ) for measuring the gas pressure (p _G ) in the container ( 1 ), - one to one in the interior of the container ( 1 ) filling opening ( 3 ) of the container ( 1 ) connected fluid supply device ( 5 ), which serves the container ( 1 ) Liquid (A, B), and - an electronic unit ( 25 ), - the basis of the after filling of the under the output pressure (p ₀ ) with the initial volume (V ₀ ) filled with gas container ( 1 ) with the pressure sensor ( 23 ) measured gas pressure (p _G ) determines the volume (V (t)) of the inflowing liquid and / or the volume flow (dV (t) / dt) of the inflowing liquid. Device according to claim 7, comprising a controller ( 33 ) provided by the liquid supply means ( 5 ) caused liquid supply depending on the measured in the container ( 1 ) flowed volume (V (t)) or the measured inflowing volume flow (dV (t) / dt) controls. Apparatus according to claim 8, wherein the controller ( 33 ) stops the supply of liquid when the measured volume (V (t)) reaches a predetermined target volume (V _SA , V _SB ). Method for operating a device according to claim 8 or 9, the liquid supply device ( 5 ) at least two storage tanks filled with liquid (A, B) ( 7 . 9 ) and a device for causing a liquid flow from the reservoirs ( 7 . 9 ) in the container ( 1 ) Comprises: - in which the gas (in the predetermined starting volume V ₀₎ under the outlet pressure (p ₀₎ is included, - the container ( 1 ) via the device for effecting the liquid flow successively with predetermined desired volume (V _SA , V _SB ) of liquids (A, B) of two or more different memories ( 7 . 9 ), wherein the achievement of the respective desired volumes (V _SA , V _SB ) of the individual liquids (A, B) is based on of the measured in the container ( 1 ) total flowed volume (V (t)) and at the beginning of the respective filling process with the respective liquid (A, B) from the respective memory ( 7 . 9 ) already in the container ( 1 ) and monitored with the device volume (V (t)) is monitored. A method according to claim 10, wherein in the successive filling of the container ( 1 ) is started with the different nominal volume (V _SA , V _SB ) of the individual liquids (A, B) with the filling with the liquid (A, B), of which the largest desired volume (V _SA , V _SB ) is required, and the filling is then successively continued in each case with the liquid (A, B), of which the next smaller desired volume (V _SA , V _SB ) is required. Device according to one of claims 7 to 9, in which - the liquid supply device ( 5 ) the liquid through a feed line (SP, SP17, SP19) into the container ( 1 ), - a volume flow of the liquid through the feed line (SP, SP17, SP19) is equal to the volume flow (dV (t) / dt) flowing into the container, and - a control device ( 35 ) provided by the liquid supply means ( 5 ) controlled liquid supply on the basis of the measured entering into the container volume flow (dV (t) / dt) such that the volume flow through the feed line (SP, SP17, SP19) and the volume flow into the container ( 1 ) corresponds to a predetermined nominal volume flow. Apparatus according to claim 12, in which - a measuring or analyzing device (SP, SP17, SP19) is provided in the feed line (SP, SP17, SP19) 37 . 37a . 37b ), - a volume flow of the liquid through the measuring or analyzing device ( 37 . 37a . 37b ) equal to the volume flow through the feed line (SP, SPa, SPb) and equal to that in the container ( 1 ) flow rate (dV (t) / dt), and - the control device ( 35 ) the volume flow through the measuring or analyzing device ( 37 . 37a . 37b ) based on the measured in the container ( 1 ) inflowing volume flow (dV (t) / dt) regulates to a predetermined nominal volume flow. Device according to one of claims 7 to 9, wherein - the liquid supply device ( 5 ) at least one filled with liquid (A, B) memory ( 7 . 9 ) and a device for causing a liquid flow of at least one of the memory ( 7 . 9 ) in the container ( 1 ), and - the device for causing the liquid flow, a controllable pneumatic pressure transducer ( 11 ), in each case via a pressure feed line provided with a controllable valve (V1, V2), in particular a 3/2-way change-over valve ( 13 . 15 ) to the memory ( 7 . 9 ), and - the liquid flow by pressurizing the liquid (A, B) in the reservoirs ( 7 . 9 ) with one of the controllable pneumatic pressure transducer ( 11 ) generated pressure (p) is effected. Apparatus according to claim 14, wherein the controllable pneumatic pressure transducer ( 11 ) via a with a controllable valve (V3), esp. A 3/2-way diverter valve, closable pressure supply line ( 21 ) to the container ( 1 ) connected. Apparatus according to claim 14 or 15, wherein the liquid supply means ( 5 ) via at least one with a valve (VR, VR1, VR2), esp. A check valve, equipped supply line ( 17 . 19 . 20 ) to the container ( 1 ) connected. Method for operating a device according to claims 14, 15 and 16, in which operating cycles are carried out, in each of which - the container ( 1 ) and the liquid (A, B) in the reservoirs ( 7 . 9 ) in advance via the 3/2 way changeover valves (V1, V2, V3) to the output pressure (p ₀ ), - the valve (V3) in the pressure transmitter ( 11 ) to the container ( 1 ) leading pressure feed line ( 21 ) is closed. By pressurizing fluid (A, B) from at least one of the reservoirs (A, B) 7 . 9 ) with one of the pressure transducer ( 11 ) generated (p) a flow of liquid into the container ( 1 ), and - finally, the total in the respective operating cycle in the container ( 1 ), in particular by pressurization, from the container ( 1 ) is discharged. Device according to claim 15 or 16, in which the container ( 1 ) via a with a valve (V _A ), esp. A check valve, ausgestalt Ablassleitung ( 27 ) to a via a vent ( 31 ) with the ambient pressure charged receptacle ( 29 ) is connected in the container ( 1 ) liquid can be removed. Method for operating a device according to Claim 18, in which the liquid is expelled from the container at the end of a filling cycle ( 1 ) is discharged by - the liquid supply to the container ( 1 ) is interrupted, and - in the container ( 1 ) contained liquid via the pressure transducer ( 11 ) is acted upon by a pressure (p), wherein the liquid through the check valve (V _A ) through the drain line ( 27 ) flows out. Method for operating a device according to claim 7, 8, 9, 12, 13, 14, 15, 16 or 18, in which operating cycles are carried out in which - gas in the predetermined output volume (V ₀ ) is below the output pressure (p ₀ ), - a liquid flow into the container ( 1 ) and the inflowing volume flow (dV (t) / dt) and / or the inflow volume (V (t)) is measured, - the liquid supply into the container ( 1 ) is interrupted before the gas pressure (p _G ) in the container ( 1 ) exceeds a predetermined maximum pressure (p _Gmax ), and - finally into the container ( 1 ) in the respective filling cycle total inflowed liquid from the container ( 1 ) is discharged.

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