densimeter with an adaptation chamber

Abstract

An arrangement for measuring the volume of a solid or liquid sample, the arrangement comprising: a first chamber for containing a sample; at least one second chamber connectable to the first chamber; a third chamber connectable to a gas supply and to a gas entry path leading to at least one of the first and second chambers; a pressure sensor; a plurality of gas paths comprising a plurality of valves; a temperature equilibration system configured to temperature equilibrate at least the first, second and third chambers to substantially the same temperature, wherein the gas paths and valves are arranged and connected to allow gas from the third chamber to be filled into at least one of the first and second chambers and to measure the pressure in at least one of the first and second chambers. Furthermore, the present application provides a method for manufacturing an arrangement for measuring the volume of a solid or liquid sample.

Description

TECHNICAL FIELD

[0001] Embodiments of the present invention generally relate to an arrangement for measuring the volume of a solid or liquid sample in the field of gravimetric measurements and to a manufacturing method for manufacturing the arrangement. BACKGROUND

[0002] The volume of a solid or liquid sample is determined using gravimetric measurements, for example for the determination of the true density, wherein a gas displacement method or a gas expansion method is performed. Thus, a sample chamber in which the sample to be measured is arranged is filled with a gas and the pressure of the gas is measured. Then, the gas is expanded into an expansion chamber and the resulting pressure is measured. By using the Boyle-Mariotte law, the volume of the sample can be determined based on the pressure measurements and based on the known volumes of the sample chamber and the expansion chamber.

[0003] The document US 4,095,437 A discloses a hydrometer designed for measuring a particular porous polymer sample. A computer calculates the density of the sample from the weight of the sample and the volume of the sample, which is determined by measuring the super-atmospheric gas pressure of a gas reservoir when isolated from the sample chamber and the equilibrium pressure established when the gas reservoir is placed in open communication with the sample chamber. The gas reservoir is linked to a gas cylinder.

[0004] The document US2017 / 0030817 A1 discloses a true density measurement device applying a gas displacement method. A sample chamber is pressurized by introducing an inert gas and releasing the gas into an expansion chamber. The volume of the expansion chamber is changed by inserting or removing a volume changing member.

[0005] The document US2017 / 0010196 A1 also discloses a true density measurement device applying a gas displacement method. A sample chamber can be closed by a lid which is pressed against the rim of an opening of the sample chamber to seal the sample chamber in a gas-tight manner.

[0006] Conventionally known hydrometers can have problems with prolonged measurement times. In particular, it has been noticed that a longer equilibration time is necessary, increasing the time required for each measurement. SUMMARY

[0007] It is therefore an object of the present invention to provide an arrangement for measuring the volume of a solid sample, wherein the measurement time is reduced and / or the accuracy of the measurement result is improved.

[0008] This object is solved by the subject matter of the present application. It should be understood that, although the appended claims do not include a multiple dependent claim, in accordance with the application, any of the claims can depend from any of the other claims as incorporated by reference in their entirety. Thus, in the submitted document, all dependent claims refer to the one claim preceding them by "followed by a comma and a blank".

[0009] According to embodiments of the application, there is provided an arrangement for measuring the volume of a solid or liquid sample, the arrangement comprising: a first (e.g. sample) chamber for containing a sample; at least one second (e.g. reference or expansion) chamber connectable to the first chamber; a third (e.g. accommodation) chamber connectable to a gas supply and to a gas entry path leading to at least one of the first and second chambers; a pressure sensor; a plurality of gas paths including the gas entry path, the plurality of gas paths comprising a plurality of valves; a temperature balancing system configured to temperature balance at least the first, second and third chambers to substantially the same temperature, wherein the gas paths and valves are arranged and connected to allow: gas exiting the third chamber to be filled into at least one of the first and second chambers; and the pressure in at least one of the first and second chambers to be measured.

[0010] The arrangement can be configured as a pycnometer. The third chamber can also be referred to as an accommodation or conditioning chamber, for conditioning the gas contained in the third chamber to a temperature substantially equal or at least similar to the temperature of the first and / or second chamber (e.g. to an accuracy of less than ±0.5°C or less than ±0.1°C). The gas used during the measurement can for example comprise an inert gas, such as helium.

[0011] SUMMARY OF EMBODIMENTS

[0012] In some embodiments, the arrangement can comprise two or more pressure sensors.

[0013] The gas entry path can selectively allow filling of either the first chamber or the second chamber, for example in two different measurement modes. In other embodiments, the gas entry path leads only to the first chamber and is not connected or leads to the second chamber. In other embodiments of the application, the gas entry path leads to or is connected to the second chamber but not to the first chamber. In order to allow selective connection of the gas entry path to either the first chamber or the second chamber, multiple gas paths and corresponding valves are necessary, which will be described in detail below. Embodiments of the application thus provide an arrangement in which the first chamber is first filled with gas and then expanded into the second chamber during measurement. Other embodiments of the application provide an arrangement in which the gas is first filled into the second chamber and then expanded into the first chamber. Embodiments of the application are thus not limited to arrangements for measuring the volume of a solid sample, in which filling and expansion of the gas can be performed bidirectionally.

[0014] The temperature equilibration system can be realized in different embodiments in different configurations. In some embodiments, the temperature equilibration system comprises two or more metal blocks separate from each other and without thermal contact to each other, each metal block comprising one or more of the first chamber, the second chamber and the third chamber.

[0015] That is, a first block can be provided which comprises the first chamber, a second block which comprises the second chamber, and a third block which comprises the third chamber. Each block can be individually equipped with and controlled by a temperature regulating device, such as a Peltier element for regulating the respective temperature.

[0016] In another embodiment, the first block can comprise the first chamber and the second chamber, while the second block (separate from and without thermal contact to the first block) comprises the third chamber. Each block can be individually equipped with and controlled by a temperature regulating device, such as a Peltier element for regulating the respective temperature.

[0017] According to embodiments of the application, the temperature equilibration system comprises a metal assembly in thermal contact with at least one of the first chamber, the second chamber, the third chamber and at least a portion of the gas path, and in thermal contact with at least one of the valves.

[0018] The metal assembly can comprise and / or include the first chamber, the second chamber and the third chamber or can only be in thermal contact with these chambers. When the chambers are housed or included in the metal assembly, these chambers can be included within the metal assembly, such as the chambers being realized as recesses or open spaces in the metal assembly in which material of the metal assembly is removed. The chambers or at least one of the chambers can be manufactured, for example, by milling out specific areas from a solid metal block or multiple metal parts, as will be described in detail below. In particular, when the metal assembly comprises or includes at least one of these chambers, and in particular when the metal assembly houses or includes all chambers, i.e. the first chamber, the second chamber and the third chamber, the gas that can be present in one or more of the chambers can equilibrate its temperature with the temperature of the metal assembly in a fast manner. In particular, the gas housed in the third chamber can also be at the temperature of the entire metal assembly at the beginning of the measurement, which is also equal to the temperature of the gas within the first and / or second chamber. Thus, when the gas is introduced or filled from the third chamber into any of the first or second chamber, the equilibration time for equilibrating the filled gas with the temperature of the first and / or second chamber can be reduced. Thus, the pressure measured by the pressure sensor can reach an equilibrium value after a shorter time range. Thus, this arrangement allows for an accelerated specific gravity measurement of the sample.

[0019] The metal assembly can comprise a single metal block, e.g. an aluminum block, or can comprise multiple metal assembly parts that are connected to each other, e.g. by bolts. The first and / or second chamber (and possibly the third chamber) can be established as a respective recess within the metal assembly or metal structure, which recess can be realized, for example, by milling or cutting. In this case, the metal assembly can comprise the first chamber, the second chamber and at least one gas path and optionally the third chamber. Thus, the limiting walls of the respective chambers can be formed by the material of the metal assembly itself. In other embodiments, the metal assembly can comprise recesses for the insertion of different containers providing the different chambers.

[0020] The third chamber is different from a mere gas conduit, as the volume of the inner space of the third chamber has a considerable size, allowing the gas inside the third chamber to be filled into the first or second chamber at the desired predetermined target pressure without the need to use any additional gas, e.g. from an external gas source. Thus, all the gas required for a typical specific gravity measurement can already be housed within the third chamber at the beginning of the measurement. The third chamber can have, for example, a cuboid or a cylindrical shape. The walls of each of the chambers can be made of a high thermal conductivity material such as metal, in particular aluminum or an aluminum alloy.

[0021] The gas paths and valves can be arranged and connected such that during the first measurement mode the gas leaving the third chamber is filled into the first chamber and can be arranged and connected such that during the second measurement mode the gas leaving the third chamber is filled into the second chamber. Thus, embodiments of the present application provide an arrangement allowing for a bidirectional operation (i.e. first filling the first chamber or first filling the second chamber and then expanding the gas into the second chamber or the first chamber, respectively), wherein the gas is introduced from the third chamber into the first or the second chamber, thereby providing a gas which has thermalized to the temperature of the metallic assembly. Other embodiments provide only a unidirectional operation from the third chamber as a filling source for the first or the second chamber.

[0022] In particular, the arrangement can be configured as a pycnometer adapted to measure the volume of the solid sample and / or the (true) density of the solid sample. For determining the density of the solid sample, in addition to determining the volume of the solid sample, determining the mass of the solid sample can be performed by the arrangement (e.g. with internal balancing) or by an auxiliary device. Alternatively, if the density of the solid sample is known, the arrangement can be adapted to measure the volume of the solid sample; then, the mass of the solid sample can be determined from these two parameters.

[0023] The arrangement can be operated, for example, in a temperature range between 5 °C and 50 °C. Thus, the chambers as well as the gas paths can be temperature-regulated to a desired temperature within the above-mentioned temperature operating range. In particular, all components of the arrangement which are in thermal contact with the measurement gas can be temperature-regulated to the same operating temperature, for example within an error range of ±1 ° or less.

[0024] The solid sample can comprise a foam and / or a powder and / or a dense sample, etc. The volume of the solid or liquid sample can be, for example, in the range of 0.1 cm 3 to 1000 cm 3 .

[0025] The first chamber and the at least one second chamber can provide an inner volume or an inner space bounded by wall portions. The chambers can have, for example, a substantially cylindrical or cuboid shape. The chambers can be bounded, for example, by different wall portions of a corresponding container or can be bounded, for example, by the material of a metallic assembly which can be in thermal contact with the chambers or which can comprise or contain the chambers.

[0026] The first chamber can for example comprise a lid or closure portion, allowing the first chamber to be opened and closed. The lid can for example be configured with a gripping portion, allowing a user to grip the lid and engage the gripping portion (e.g. by a rotational movement) at an engagement portion of the first chamber. When the first chamber is opened, a sample can be introduced into the first chamber. After the sample has been placed into the first chamber, also referred to as sample chamber, the first chamber can be closed by the lid, i.e. in a gas-tight manner.

[0027] For example, the operating relative pressure can be in the range of -1 bar to 10 bar, for example after filling of the first chamber or filling of the at least one second chamber. The lid can comprise a sealing device to maintain the gas within the first chamber at the desired operating pressure when the first chamber is closed by the lid.

[0028] The at least one second chamber, also referred to as reference chamber, can not comprise a lid. The at least one second reference chamber can be connected to the first chamber when the third valve and the fourth valve are in an open state.

[0029] When the chamber can be connected to or is connected to another chamber, this can mean that the gas contained in the chamber can be in free communication with the space or interior volume of the other chamber. Thus, when for example the first chamber is connected to the second chamber, the gas in the first chamber and the gas in the second chamber can mix with each other and can be distributed through the first chamber and the second chamber to reach the same pressure and to completely fill the free volume of the first chamber and the interior volume of the second chamber. When the chamber is connected to a specific valve, this means that the gas contained in the chamber and / or the respective valve can be in free communication with the valve or the chamber, respectively.

[0030] The pressure sensor can for example be configured to measure relative pressures in the operating range of -1 bar to 10 bar. The pressure sensor can also be temperature-regulated to have substantially the same temperature as the chambers and the valves. All gas paths, valves and all chambers can also be gas-tight in the above-mentioned pressure range.

[0031] According to embodiments of the present application, the interior volume of the third chamber has a size between 0.1 times and 100 times the size of the interior volume of one of the first chamber and the second chamber.

[0032] The gas contained in the third chamber can be pressurized in particular at a pressure which is at least as high as the target pressure required for filling the first chamber or the second chamber or even higher. In particular, the gas filled into the third chamber can for example have a relative pressure of between 0.1 bar and 200 bar.

[0033] The relative target pressure after filling the first or second chamber can for example be in the range of -1 bar to 10 bar. When the inner volume of the third chamber has the dimensions as specified above, the gas needed for filling the first or second chamber can be completely accommodated in the third chamber without the need to fill additional gas into the first or second chamber which was not previously equilibrated and accommodated in the third chamber. Thus, typical measurement procedures can be complied with.

[0034] According to embodiments of the present application, the third chamber encloses a metal material providing a high surface area, wherein the metal material is in thermal contact with the metal assembly, wherein the metal material comprises at least one of the following: a fiber mesh, a sintered structure, a loose material, a mesh, a fleece, a fabric, a non-woven fabric, a woven fabric, and a mat.

[0035] The metal material can also comprise metal spheres, metal powder or any other metal which improves the thermal conductivity between the gas and the chamber. When the metal material is enclosed in the third chamber and in thermal contact with the metal assembly, the gas surrounding the metal material in the third chamber can reach the temperature of the metal assembly in a fast manner. As the temperature of the metal assembly substantially corresponds to or is equal to the temperature of the first and second chamber, the equilibration time for equilibrating the gas to the temperature of the first or second chamber after filling the gas into the respective chamber can also be shortened. The metal material can be constructed in a variety of different ways. It is only required that the surface area of the metal material is much larger than the surface area of the metal material when the metal material is in a continuous or compact structure.

[0036] According to embodiments of the present application, the arrangement further comprises a temperature regulating device for regulating the temperature of the metal assembly to a desired temperature, a thermal insulation surrounding the metal assembly.

[0037] The temperature regulating device can comprise an electrical heater and a cooler, in particular at least one Peltier element which is capable of heating and / or cooling the metal assembly. The metal assembly can provide a large heat capacity and can be a good heat conductor. Basically, the temperature can be equal or at least very similar throughout the entire extent of the metal assembly. Thus, the temperature within the different chambers and gas paths can also be substantially the same or at least very similar. As the pressure and / or volume of the gas depends on the temperature in a dedicated or sensitive manner, providing an equal temperature in all involved parts of the measurement can improve the reliability and / or accuracy of the volume determination. Providing a hole in the metal assembly can be easily realized. Thus, different elements for the gas paths can no longer be required or necessary.

[0038] According to embodiments of the present application, the metal component comprises each of: a first metal part comprising a first chamber; a second metal part comprising a second chamber; and a third metal part comprising a third chamber, wherein the first metal part is mounted to a side flat surface of the second metal part at a side flat surface and another side flat surface of the second metal part is mounted at a side flat surface of the third metal part.

[0039] When the metal assembly is assembled from the first metal part, the second metal part and the optional third metal part, a simple structure is provided which is easy to manufacture. The joint between the part of the one or more flow paths between adjacent metal parts of the metal assembly can be provided with a respective seal, such as an O-ring, to prevent leakage at the mounting joint of the metal parts. Thus, a compact arrangement can be achieved.

[0040] According to embodiments of the present application, the gas paths and valves comprise at least one of: a first gas (e.g. supply) path comprising a first valve, the first gas path being connected to the first chamber via the first valve on one end and to the gas entry path on the other end; and a second gas (e.g. supply) path comprising a second valve, the second gas path being connected to the second chamber via the second valve on one end and to the gas entry path on the other end.

[0041] According to embodiments of the present application, the arrangement comprises at least one of: a third gas (e.g. measurement) path comprising a third valve, the third gas path being connected to the first chamber on one end and to the pressure sensor via the third valve on the other end; and a fourth gas (e.g. measurement) path comprising a fourth valve, the fourth path being connected to the second chamber on one end and to the pressure sensor via the fourth valve on the other end.

[0042] Any of the gas paths can be formed by a gas conduit, e.g. a gas conduit having a substantially annular cross-sectional shape, wherein the gas path is adapted to guide or carry a gas without substantially contaminating the gas, without absorbing components of the gas and without changing the composition of the gas. The gas paths and chambers can be adapted to fill or guide any of the conventionally known measurement gases, say such as a noble gas or an inert gas, e.g. nitrogen. In particular, helium can be used as the measurement gas. All valves, i.e. the first valve, the second valve, the third valve, the fourth valve, can be substantially configured in the same way, in particular as solenoid valves and more particularly as two-way self-locking valves.

[0043] The first gas path can also be referred to as a first gas supply path, since it can provide the opportunity to supply a measurement gas into the first chamber. The second gas path can also be referred to as a second gas supply path, since it can enable filling a measurement gas into the second chamber. The third gas path can also be referred to as a third gas measurement path, since it can be used to expand gas from the first chamber during a measurement or to connect the pressure sensor with the first chamber to measure the pressure after the measurement gas has been filled into the first chamber. The fourth gas path can also be referred to as a fourth gas measurement path, since it can be used to expand gas that has been contained within the first chamber (or the second chamber) to the second chamber (or the first chamber) via the third and fourth valves during a measurement. In this case, the fourth gas path connects the first chamber with the second chamber and also connects both inner volumes of both chambers to the pressure transducer or pressure sensor. According to embodiments of the present invention, the third and fourth gas paths can be used to connect the first and second chambers with each other and with the pressure sensor.

[0044] By providing the first, second, third, and fourth gas paths comprising the respective first, second, third, and fourth valves, the arrangement allows measuring the volume of a sample in two different modes of operation. In a first mode of operation, the first (sample) chamber is first filled with a measurement gas, which is then expanded into the second (reference) chamber. In a second mode of operation, the second chamber is first filled with a measurement gas, which is then expanded into the first chamber. In both modes of measurement, the sample can be placed into the first chamber. By providing two different modes of measurement featuring the measurement gas to be expanded flowing in opposite directions, accurate and reliable measurements can be made for various different types of samples.

[0045] According to embodiments of the present invention, the arrangement comprises at least one of: a fifth gas (drain) path comprising a fifth valve, the fifth gas path being connected to the first chamber via the fifth valve on one end and to a gas receiver on the other end; and a sixth (e.g. drain) path comprising a sixth valve, the sixth gas path being connected to the second chamber via the sixth valve on one end and to the gas receiver on the other end.

[0046] The fifth gas path can also be referred to as a fifth gas venting path, since the fifth gas path is used to vent the first and / or second chamber and the connecting gas paths after a measurement has been performed according to the first measurement mode. Alternatively, the fifth gas path can be used to vent the chambers and gas paths after a measurement has been performed according to the second measurement mode. Thus, only one vent is required and this vent can be positioned anywhere in the instrument.

[0047] The sixth gas path comprising the sixth valve can be used to vent the system after a measurement has been performed using the first measurement mode. Alternatively, venting the sixth valve can also be performed after a measurement has been performed according to the second measurement mode. Embodiments of the present invention comprise only one of these valves, i.e. the fifth valve and the fifth gas path or the sixth valve and the sixth gas path. In this case, any of the fifth or sixth valves can be used (and are present) to vent the system after having performed either one of the operational measurement modes. In other embodiments, both the fifth and sixth valves and the fifth and sixth gas paths can be present.

[0048] According to embodiments of the present invention, the arrangement further comprises a controller adapted to control the state of at least one of the first, second, third, fourth (and in particular fifth and sixth) valves, thereby allowing to selectively measure a sample volume according to a first measurement mode or a second measurement mode, wherein in the first measurement mode the first chamber in which the sample is accommodated is filled with gas from the third chamber, which gas is then expanded into the second chamber, wherein in the second measurement mode the second chamber is filled with gas from the third chamber, which gas is then expanded into the first chamber in which the sample is accommodated.

[0049] The controller can be communicatively connected to the different valves via electrical and / or optical and / or wireless control lines. The controller can also be communicatively connected to the pressure sensors, e.g. for reading out pressure measurement signals.

[0050] Each of the valves can be adapted to be in two different states, an open state and a closed state. In the closed state, the respective valve can interrupt the communication of gas between the two sides of the respective valve. In the open state, the respective valve can freely allow the communication of gas through the different sides of the respective valve (e.g. in one of the gas paths). The respective valve can comprise a simple solenoid valve, which can be in the closed state, unless specifically activated by a control signal or control current. In other embodiments, to switch the valve between the closed and open state, a single current pulse can be provided to the respective valve, which is configured as a two-way self-locking valve.

[0051] The controller can be adapted to control the state of the first, second, third, fourth, and in particular fifth and sixth valves, which will be further explained below. Controlling the state of the respective valves allows to perform a measurement method for determining the volume of a solid sample. The controller may, for example, control a respective driver for the valves, which can generate and send a suitable driver signal according to a control signal sent from the controller, thereby adjusting or changing the state of the respective valve.

[0052] The gas inlet path may, for example, be connected with a gas container containing the measurement gas. The gas container can be in thermal contact or not in thermal contact with the respective chambers and valves. In a particular embodiment of the application, the gas inlet path including the gas container (also referred to as third chamber) can be in thermal contact with the first, second and different valves, and in particular can be kept at the same temperature as the first, second and different valves.

[0053] For employing the first or second measurement mode, no physical changes or rearrangements of any part of the arrangement can be necessary. By simply switching the state of the different valves appropriately, the first or second measurement mode can be selectively established. Thus, reliable measurements can be performed for various different types of samples. For example, a first group of sample types can preferably be measured using the first measurement mode, and a second group of sample types can preferably be measured by the second measurement mode. A user operating the arrangement may, for example, simply input the respective type of sample for which a measurement is desired into an input interface. Based on the input sample type, the arrangement can automatically switch to the appropriate measurement mode, i.e. to the first or to the second measurement mode, without further user intervention / input. In other embodiments, the type of measurement mode, i.e. the first or second measurement mode, can be directly input by the user.

[0054] According to an embodiment of the application, the controller is adapted to, when in the first measurement mode, cause: opening of the first and third valves to allow filling of the first chamber with gas from the third chamber, closing of the first valve and measuring a first pressure related to the first measurement mode using the pressure sensor, e.g. after reaching equilibrium, e.g. when the first, second, fourth, fifth and sixth valves (and the seventh and eighth valves) are closed; opening of the fourth valve (and optionally the seventh valve leading to another second chamber) to allow expansion of the gas also into the at least one second chamber and measuring a second pressure related to the first measurement mode, wherein the arrangement is adapted to calculate the volume of the sample based on the first and second pressures both related to the first measurement mode.

[0055] The first and third valves can be opened simultaneously or sequentially. For example, the third valve can be opened, i.e. set into an open state, and the first valve can be opened simultaneously or after opening the third valve. The first and third valves can remain open until the pressure (as measured by the pressure sensor) within the first chamber and the third gas path and the first gas path reaches a target pressure, which can for example be in a range between -1 bar to 10 bar. After reaching the target pressure, the first valve can be closed (i.e. set into a closed state) and the first pressure (related to the first measurement mode) can be measured using the pressure sensor. Thus, the pressure can be measured by the pressure sensor until the measured pressure does not vary by a configurable threshold, thereby specifying a rate of change limit / threshold. Thus, it can be waited until the gas temperature within the sample chamber and the third gas path essentially assumes the temperature of the one or more wall portions confining the sample chamber and the material confining the third path. Thus, the first gas pressure can be determined after reaching an equilibrium in terms of gas temperature. The first gas pressure can be measured while the first, second, fourth, fifth and sixth valves (and optionally the seventh and eighth valves) are closed.

[0056] After measuring the first pressure (related to the first measurement mode), the fourth valve (and optionally the seventh valve as explained herein) can be opened, allowing the gas to expand from the first chamber into the at least one second chamber. Also, the second pressure (related to the first measurement mode) can be measured after reaching an equilibrium, in particular an equilibrium with respect to the gas temperature. Thus, for example, the pressure measured by the pressure sensor can be tracked and followed until the measured pressure does not vary significantly anymore, thereby changing less than a threshold after a predetermined time interval.

[0057] The arrangement (e.g. comprising the processor) can use the volume of the first and second chambers (which are known beforehand) in addition to the first and second pressures and can use further calibration data as detailed herein below to determine the volume.

[0058] According to an embodiment of the present application, the controller is adapted to, when in the second measurement mode, cause: opening of the second and fourth valves (optionally the seventh valve) to allow filling of the second chamber with gas from the third chamber, closing of the second valve and measuring of a first pressure related to the second measurement mode using the pressure sensor (e.g. after reaching an equilibrium), for example while the first, second, third, fifth and sixth valves and the seventh and eighth valves are closed; opening of the third valve to allow also expanding of the gas into the first chamber and measuring of a second pressure related to the second measurement mode, wherein the arrangement is adapted to calculate the volume of the sample based on the first and second pressures both related to the second measurement mode.

[0059] For example, the fourth valve and the second valve can be opened simultaneously or sequentially. If it is desired that a larger volume of the volume of the second chamber is filled with gas, optionally also the seventh valve can be opened. The seventh valve can connect the second chamber to another second chamber. The second chamber and optionally also the other second chamber can be filled with the measuring gas until a target pressure is reached in the second chamber (and optionally also the other second chamber) and in the second gas path and the fourth gas path. When the target pressure is reached, the second valve can be closed. Then, in particular after equilibration, the first pressure (related to the second measurement mode) can be measured by the pressure sensor. During the measurement of the first pressure, the first valve, the second valve, the third valve, the fifth valve and the sixth valve and also the seventh valve and the eighth valve can be closed.

[0060] After the first pressure (related to the second measurement mode) has been measured, the third valve can be opened, thereby connecting the second chamber with the first chamber and allowing the gas to expand through the second chamber and the first chamber and the third path. After equilibration has been reached (for example determined by tracking the measured pressure and the measured pressure does not change significantly over time), the second pressure (related to the second measurement mode) can be measured. In the second measurement mode, the arrangement (processor) calculates the volume of the sample based on the first pressure and the second pressure (both related to the second measurement mode) and optionally also based on the known internal volumes of the first chamber, the second chamber, the fourth gas path and the third gas path.

[0061] Furthermore, the calculation of the volume of the sample during either of the measurement modes can also be based on a partial volume of the first gas path, in particular the volume of the first gas path between the first valve and the first chamber. Furthermore, the calculation can be based on a part of the second gas path, namely the part between the second valve and the second chamber. Thus, according to embodiments of the present invention, at least a partial volume of the gas paths can be considered for the calculation of the sample volume. These specific parts of the gas paths can be known beforehand and can be stored in an electronic memory, for example as calibration data.

[0062] According to embodiments of the present invention, the controller is adapted to cause at least one of: after the measurement of the second pressure related to the first measurement mode, opening the fifth valve to allow the gas to be discharged from the first chamber and the second chamber to a gas receiver; and after the measurement of the second pressure related to the second measurement mode, opening the sixth valve to allow the gas to be discharged from the first chamber and the second chamber to a gas receiver.

[0063] Thus, it can be provided that the system is discharged to the same gas receiver without physically changing any of the gas paths.

[0064] According to embodiments of the application, at least one of the first valve, the second valve, the third valve, the fourth valve, in particular the fifth valve and the sixth valve, comprises a one-way valve having a sealed input side.

[0065] The one-way valve can have only one sealed side, namely the input side (also referred to as supply side). The one-way valve can only be subjected to a gas leak from the input side of the respective valve, but not from the output side (outlet side). In comparison to a two-way valve having two sealed sides, the one-way valve can have substantially smaller dimensions and size as well as weight. Thus, the complexity, size and weight of the arrangement can be reduced. Furthermore, the fifth valve and the sixth valve, and possibly the eighth valve and the seventh valve, can also comprise or be a valve having one sealed input side.

[0066] According to embodiments of the application, at least one of the following is applicable: the input side of the first valve faces and / or is connected to the first chamber; the input side of the second valve faces and / or is connected to the second chamber; the input side of the third valve faces and / or is connected to the pressure sensor; the input side of the fourth valve faces and / or is connected to the pressure sensor; the input side of the fourth valve is connected to the first chamber if the third valve is in the open state; the input side of the third valve is connected to the second chamber if the fourth valve is in the open state.

[0067] When the input side of the first valve faces or is connected to the first chamber, the first valve can effectively prevent a gas leak from the first chamber via the first valve when the first valve is in the closed state. When the second valve faces or is connected to the second chamber, the second valve can effectively prevent a gas leak from the second chamber via the second valve when in the closed state. When the third valve faces or is connected to the pressure sensor, the third valve can prevent a gas leak via the third valve, for example in the second measurement mode when the first pressure (related to the second measurement mode) is to be measured after the second chamber has been filled. When the fourth valve faces or is connected to the pressure sensor, the fourth valve can effectively prevent a gas leak via the fourth valve when the first chamber has been filled with gas and the first pressure (related to the first measurement mode) is to be measured in the first measurement mode. Thus, the first measurement mode and the second measurement mode can be performed.

[0068] According to embodiments of the application, the arrangement further comprises at least one of: a seventh gas path comprising a seventh valve and connecting the second chamber to a further second chamber; and an eighth gas path comprising an eighth valve, the eighth gas path being connected on one end to the first valve, the second valve and the gas inlet path and on the other end to a further gas receiver. The eighth valve can at one end have its input side connected to the output sides of the first valve and the second valve and to the gas inlet path.

[0069] The seventh gas path and the second chamber provide the opportunity to initially fill a higher volume of gas or a larger mass of gas into the second chamber and the further second chamber. This gas contained in the second chamber and the further second chamber can then be expanded into the first chamber. However, in the first measurement mode, the first chamber is first filled with gas and the gas can be expanded into the combination of the first chamber and the second chamber. Thus, different measurement configurations are provided depending on the size or volume of the sample or other considerations.

[0070] The seventh valve can also optionally be opened if it is desired to fill a larger volume than the volume of the second chamber with gas. The seventh valve can connect the second chamber to a further second chamber. The second chamber and optionally the further second chamber can be filled with the measurement gas until a target pressure is reached in the second chamber (and optionally the further second chamber) and in the second gas path and the fourth gas path.

[0071] According to embodiments of the application, the arrangement further comprises: a processor adapted to calculate the volume of the sample based on at least the pressure measurements and the volumes of the first chamber and the second chamber (e.g. using the Boyle-Charles law); and an electronic memory accessible to the processor and containing volume calibration data of the first chamber and the second chamber for use in the calculation of the volume of the sample.

[0072] The processor can for example comprise or execute a computer program which is loaded into a memory in communication with the processor. The calculation can use the Boyle-Charles law as known from thermodynamics. The Boyle-Charles law can assume the validity of the ideal gas equation. In other embodiments, a modified equation can be used which takes into account deviations of real gases from ideal gas behavior instead of the Boyle-Charles law which assumes an ideal gas. The processor can be communicatively connected to the controller, e.g. the processor also provides control signals to the controller for appropriate control of the valves according to the measurement procedure.

[0073] The processor can also be communicatively connected to a pressure sensor to receive a pressure measurement signal. Furthermore, the processor can be adapted with or can be communicatively connected to one or more temperature sensors arranged to measure the temperature of different chambers and / or different gas paths. The processor can receive a temperature measurement of a temperature sensor configured to measure the temperature of a metal assembly comprising all chambers and all gas paths (or in thermal contact with all chambers and all gas paths). It can then be assumed that all sample chambers and gas paths have essentially the same temperature as determined by the temperature measurement sensor, or the respective temperatures of the different elements can be derived from the temperature measured by the temperature sensor using, for example, temperature calibration data.

[0074] It is to be understood that features disclosed, provided, explained or applied in connection with the arrangement for measuring the volume of a solid sample, alone or in any combination, according to embodiments of the present application can also be disclosed, provided, explained or applied in connection with the manufacturing method for manufacturing the arrangement for measuring the volume of a solid sample, alone or in any combination, and vice versa.

[0075] According to embodiments of the present application, a method for manufacturing an arrangement for measuring the volume of a solid or liquid sample is provided, the method comprising: providing a first chamber for accommodating a sample; providing at least one second chamber, the at least one second chamber being connectable to the first chamber; providing a third chamber, the third chamber being connectable to a gas supply and to a gas entry path leading to at least one of the first chamber and the second chamber; providing a temperature equilibration system configured to temperature regulate at least the first chamber, the second chamber and the third chamber to substantially the same temperature; providing a pressure sensor; arranging and connecting a plurality of gas paths comprising a plurality of valves to allow: filling of gas leaving the third chamber into at least one of the first chamber and the second chamber; and measuring a pressure in at least one of the first chamber and the second chamber.

[0076] Embodiments of the present application provide an arrangement and a corresponding manufacturing method, wherein the temperature of the gas inside the first chamber (also referred to as sample chamber) and the second chamber (also referred to as reference chamber) and the third chamber (also referred to as accommodation chamber) is substantially the same. Thus, introducing gas from the third chamber into either one of the first chamber or the second chamber does not disturb the thermal system, such that the equilibration time of the gas temperature for filling into either one of the first chamber or the second chamber actually assumes the temperature of the surrounding chamber walls, i.e. substantially corresponds to the temperature of the metal assembly, is reduced.

[0077] Thus, the third chamber can act as an adaptation chamber or conditioning chamber installed in addition to the sample chamber and the reference chamber and has a sufficiently large volume and shares the same thermal control system with the first and second chambers. Thus, the temperature of the gas introduced into the sample chamber or the reference chamber has already reached the temperature prevailing also in the first and / or second chamber. Thus, a densimeter with the highest accuracy is advantageously provided, since the temperature of the gas in the different chambers should ideally be uniform between the sample chamber and the expansion chamber or the reference chamber.

[0078] According to embodiments of the application, by filling the gas from the third chamber into the first or second chamber, only gas that has equilibrated to the temperature of the first or second chamber enters the first or second chamber. According to embodiments of the application, the waiting time until the first or the further first pressure reaches a stable value is shorter than with commonly known arrangements or instruments. In prior art solutions, there can be a large temperature difference between the working temperature of the instrument and the initial gas temperature, which can typically be room temperature.

[0079] According to embodiments of the application, the densimetric measurement performed by the arrangement can be carried out at a gas temperature of between 5°C to 50°C. The corresponding target temperature can be adjusted to a specific target temperature using or controlling a temperature regulating device. In particular, when performing the measurement with the arrangement at a target temperature different from room temperature or ambient temperature, it can be particularly advantageous that the gas contained in the third chamber has been temperature-regulated to the target temperature before filling the gas into the first or second chamber. According to embodiments of the application, the gas is introduced at the instrument working temperature (or target temperature).

[0080] The adaptation chamber can be a third volume in a metal block or metal assembly. In particular, it can not be necessary to know the exact volume of the third chamber and it can not be necessary to provide a pressure transducer for an accurate measurement of the pressure in the conditioning chamber. The conditioning chamber can be connected to a gas supply providing a specific filling pressure.

[0081] In order to improve the heat transfer between the gas in the third chamber and the metal material of the metal assembly, the interior space of the third chamber can be filled with a material (such as metal wool) that increases the contact surface area that can exchange heat with the gas contained in the third chamber. Thus, the gas contained in the third chamber can even equilibrate more quickly with the temperature of the metal assembly.

[0082] In particular, a gas input pipe (e.g. from a gas source) can be directly connected to the third chamber or to the accommodation chamber. This can also be beneficial because the input pipe can usually be at a higher pressure than the working pressure of the instrument. Thus, the accommodation chamber can contain more gas, meaning that the gas needs to stay longer in the instrument before. Furthermore, the introduction of the third chamber into the arrangement can improve the measurement accuracy of the arrangement, in particular of the densimeter.

[0083] Usually, the gas can enter the sample chamber (or the reference chamber, depending on the measurement mode) at a different temperature than the temperature of the whole arrangement or the temperature of the metal components, and it can be very important to wait until the gas reaches the temperature of the instrument. The embodiments of the present invention reduce the waiting time.

[0084] In order to know that the gas actually reached equilibrium or the temperature of the metal components, usually, the pressure in the chamber can be tracked until the pressure is stable. Thus, it can be necessary to define "pressure stable". Usually, equilibrium is considered to be complete when the pressure does not change by more than a threshold or limit within a certain time interval or when the change of the pressure over time is below a limit (e.g. the pressure change is less than 0.001 Torr / min). This parameter can also usually be chosen considering the measurement duration and thus does not always ensure perfect temperature stabilization.

[0085] According to embodiments of the present invention, a relatively strict threshold is chosen to define that equilibrium has been completed. For example, the threshold to be reached for judging that equilibrium has been completed can be set to e.g. 0.3 mTorr / min. Because the threshold can be more strict than usually defined, the measurement accuracy can also be higher than usually observed. BRIEF DESCRIPTION OF DRAWINGS

[0086] Figure 1 a fluidic diagram illustrating schematically an arrangement for measuring the volume of a solid sample according to embodiments of the present invention; and

[0087] Figure 2 a perspective exploded view of the arrangement shown in Figure 1 Fig. 1 according to embodiments of the present invention. DETAILED DESCRIPTION

[0088] Figure 1The arrangement 100 for measuring the volume of a solid sample 101 shown in the middle comprises a first chamber 103 for containing the sample 101, at least one second chamber 105 (and optionally a further second chamber 106) connectable to the first chamber 103. Further, the arrangement 100 comprises a third chamber (also referred to as an accommodation chamber) 185 connectable to a gas supply 181 and to a gas entry path 115 leading to at least one of the first chamber 103 and the second chamber 105. Further, the arrangement 100 comprises a pressure sensor 123 and a plurality of gas paths with a plurality of valves, which will be explained in detail below.

[0089] Further, the arrangement 100 comprises a metal component 160 which is in thermal contact with at least the first chamber 103, the second chamber 105, the third chamber 185 and at least a portion of at least one of the gas paths, or which at least comprises or contains the first chamber 103, the second chamber 105, the third chamber 185 and at least a portion of at least one of the gas paths, and which is in thermal contact with at least one of the valves.

[0090] The metal component 160 at least partially implements a temperature balancing system configured to at least temperature-regulate the first chamber 103, the second chamber 105 and the third chamber 185 to substantially the same temperature.

[0091] The gas paths and valves, in particular the gas paths 107, 117, 123, 133, 125, 175, 171 and in particular the valves 119, 109, 135, 127, 151, 153 and 155, 157 are arranged and connected to allow gas leaving the third chamber 185 to fill at least one of the first chamber 103 and the second chamber 105 and to allow pressure measurement in at least one of the first chamber 103 and the second chamber 105.

[0092] Further, the arrangement 100 comprises a first gas supply path 107 comprising a first valve 109, wherein the first gas path 107 is connected to the first chamber 103 via the first valve 109 on one end 111 and to the gas entry path 115 on the other end 113. The arrangement further comprises a second gas supply path 117 comprising a second valve 119, wherein the second gas path 117 is connected to the second chamber 105 via the second valve 119 on one end 121 and to the gas entry path 115 on the other end 124.

[0093] The arrangement 100 further comprises a pressure sensor 123 and a third gas measuring path 125 comprising a third valve 127, the third gas path 125 being connected to the first chamber 103 on one end 129 and to the pressure sensor 123 on the other end 139 via the third valve 127. The arrangement 100 further comprises a fourth gas measuring path 133 comprising a fourth valve 135, the fourth gas path 133 being connected to the second chamber 105 on one end 137 and to the pressure sensor 123 on the other end 139 via the fourth valve 135.

[0094] The arrangement 100 further comprises a controller 150 adapted to control the state of the first valve 109, the second valve 119, the third valve 127, the fourth valve 135 and in particular also the fifth valve 151, the sixth valve 153, the seventh valve 155 and the eighth valve 157 to allow selective measurement of the sample volume according to the first or second measurement mode. The controller thus receives a pressure measurement signal 166 from the pressure sensor 123.

[0095] In the first measurement mode, the first chamber 103 in which the sample 101 is accommodated is filled with gas from the gas inlet path 115 and the gas is then expanded into the second chamber 105. In the second measurement mode, the second chamber 105 is filled with gas from the gas inlet path 115 and the gas is then expanded into the first chamber 103 in which the sample 101 is accommodated. In the first and second measurement modes, the gas is expelled via the gas receiver 159.

[0096] The controller 150 provides valve control signals 161 to the respective valves to control the valves. When in the first measurement mode, the controller 150 is adapted to open the first valve 109 and the third valve 127 by the control signals 161 to allow the first chamber 103 to be filled with gas from the gas inlet path 115, to close the first valve 109 and to measure a first pressure (related to the first measurement mode) using the pressure sensor 123. Furthermore, the controller 150 opens the fourth valve 135 and optionally the seventh valve 155 to allow the gas to be expanded into the at least one second chamber 105 and in particular also optionally into the further second chamber 106 via the seventh valve 155. Then, a second pressure (related to the first measurement mode) can be measured and a processor 163 comprised in the controller 150 calculates the volume of the sample 101 based on the first pressure and the second pressure.

[0097] When in the second measurement mode, the controller 150 is adapted to open the second valve 119 and the fourth valve 135 to allow the second chamber 105 to be filled with gas from the gas inlet path (and optionally also the other second chamber 106 by additionally opening the seventh valve 155). Then, the first pressure (related to the second measurement mode) can be measured using the pressure sensor 123. Further, the controller 150 opens the third valve 127 to allow the gas to expand into the first chamber 103 and to measure the second pressure (related to the second measurement mode). Then, the processor 163 is adapted to calculate the volume of the sample 101 based on the first pressure and the second pressure (both related to the second measurement mode).

[0098] For the purpose of venting, the arrangement 100 comprises a fifth gas venting path 165 comprising a fifth valve 151, wherein the fifth gas path 165 is connected to the first chamber 103 via the fifth valve 151 on one end 167 and to the gas receiver 159 on the other end 169. The arrangement further comprises a sixth gas venting path 171 comprising a sixth valve 153, the sixth gas path 171 being connected to the second chamber 105 on one end 173 and to the gas receiver 159 on the other end 175.

[0099] In the shown embodiment, the valves are realized or configured as one-way two-way self-locking valves having an input side and an output side or supply side and outlet side, wherein the supply side or input side is depicted as an open circle and the output side as a closed or filled circle. As can be seen from Figure 1 The input side of the first valve 109 faces the first chamber 103. Further, the input side of the second valve 119 faces the second chamber 105. Further, the input side of the third valve 127 faces the pressure sensor 123. Further, the input side of the fourth valve 135 also faces the pressure sensor 123. Further, the input side of the fourth valve 135 is connected to the first chamber 103 if the third valve 127 is in the open state. Further, the input side of the third valve 127 is connected to the second chamber 105 if the fourth valve 135 is in the open state.

[0100] The arrangement 100 further comprises an eighth valve 157 connected on one end to the first valve 109, the second valve 119 and the gas inlet path 115 and on the other end to another gas receiver 177. The arrangement 100, in particular the controller 150, comprises an electronic memory 183 containing volume calibration data and / or temperature calibration data.

[0101] The gas path 115 comprises a gas supply valve 179 connected to a gas container 181. The gas inlet path 115 can or can not comprise an accommodation chamber 185. Thus, in embodiments the accommodation chamber 185 is not present.

[0102] However, Figure 1 The arrangement 100 shown in Fig. 1 further comprises a third chamber 185 for accommodation purposes, which is connected to the gas supply 181, 179 and provides the gas inlet path 115 into the first gas path 107 and the second gas path 117, wherein the third chamber 185 is in thermal contact with or comprised in the metal assembly 160. The metal assembly 160 is further in thermal contact with or comprises the first chamber 103, the second chamber 105 and the gas paths 107, 117, 133, 125, 165, 171 and all valves 109, 151, 153, 155, 135, 127, 119, 157. A temperature regulating device 162, e.g. comprising a Peltier element, is further provided and is in thermal contact with the metal assembly 160 for temperature regulating the metal assembly 160 to a desired temperature. The temperature regulating device 162 is controlled by a control signal 164 from the controller 150.

[0103] The third chamber 185 can have a volume, e.g. in the range of 0.1 to 10 times the volume of the second chamber 105 or the first chamber 103. Thus, the third chamber 185 is in Figure 1 Not to scale in Fig. 1. The third chamber can be filled with a not shown mesh filter or metal mesh, e.g. a woven wire mesh filter. It should be noted that the third chamber 185 is an optional feature of the arrangement 100 and can not be present in other embodiments of the present invention.

[0104] As Figure 1 As shown in Fig. 1, the sample chamber 103 is closed by a lid 104. For loading the sample 101 into the first chamber 103, the lid 104 can be removed by a user.

[0105] According to embodiments, the arrangement comprises a second gas path 121, a second valve 119, a fourth gas path 133, a fourth valve 135, a third gas path 125, a third valve 127, a fifth gas path 165 and a fifth valve 151. However, the arrangement can only optionally comprise Figure 1 Further paths and valves as shown in Fig. 1.

[0106] The third chamber 185 can have a volume, e.g. in the range of 0.1 to 10 times the volume of the second chamber 105 or the first chamber 103. Thus, the third chamber 185 is in

[0107] Figure 2 An arrangement for measuring the volume of a solid sample, implemented according to an embodiment of the application, is illustrated in perspective exploded view. Figure 1 and Figure 2 Structurally and / or functionally similar elements in the figures are labeled with the same reference signs, differing only in the first digit. A description of an element not described in detail in one particular embodiment can be obtained by the description of the corresponding element in the context or the figures of another embodiment.

[0108] The arrangement 200 comprises a metal assembly 202 comprising a first metal part 210 comprising a first chamber not visible, a second metal part 206 comprising a second chamber not visible, and a third metal part 208 comprising a third chamber not visible. Wherein the first metal part 210 (in the assembled arrangement 200) is mounted to a side flat surface of the second metal part 206, or another side flat surface of the second metal part 206 is mounted at a side flat surface of the third metal part 208. Thus, the first, second and third metal parts are arranged in series.

[0109] Figure 1 In the figures, a cover 204 for closing the first chamber comprised in the first metal part 210 is also shown, the cover 204 comprising a grip portion 212 allowing to twist or turn the cover 204, the cover 204 comprising a hook 216 for engaging or disengaging with an engagement portion 214 connected to the first metal part 210.

[0110] As Figure 2 As can be seen in the figures, some or all gas paths are implemented by holes in the metal parts 210, 206, 208. For example, the first gas path 207, the second gas path 217 and the sixth gas path 271 are shown as holes in the respective parts. Further, the first gas path 207, the second gas path 217 and the sixth gas path 271 are implemented by holes in the metal parts 210, 206, 208. Figure 2 As can be seen in the figures, valves are mounted at the outer surface of the metal assembly 202. In particular, for example, the second valve 219 (or another valve) is surface mounted at the outer surface of the third metal part 208. The third metal part 208 can be covered with a plate 222. The first valve 209, the third valve 227, the fourth valve 235 and / or the fifth valve 251 (or other valves) can be mounted at the outer surface of the second metal part. As can be seen in the figures, the first valve 209, the third valve 227, the fourth valve 235 and / or the fifth valve 251 (or other valves) are surface mounted at the outer surface of the second metal part. Figure 2It can further be seen that the sealing ring 218 provides an airtight connection between the different components when assembled. The three metal parts 210, 206, 208 can be mounted to each other, for example, using bolts 220. Further, a pressure sensor or pressure transducer 223 is shown and also surface mounted to the metal assembly.

[0111] As Figure 2 As shown in the middle, a third chamber is comprised in the third metal part 208. The bore within this metal part 208 partly forms a path in one or more gas paths to allow filling of gas from the third chamber into the second chamber comprised within the second metal part 206 of the metal assembly 202 or into the first chamber comprised within the first metal part 210 of the metal assembly 202.

[0112] When a regular solid is to be measured, a second measurement mode can be employed, in which the second chamber 105 (and optionally also the further second chamber 106) is first filled with gas. Thereafter, after measuring the first pressure (related to the second measurement mode), the gas can be expanded into the first chamber, i.e. the sample chamber.

[0113] If a foam or similar type of material is to be measured, a first measurement mode can be employed. Thus, the first chamber is first pressurized, i.e. filled with gas, exchanging the function of each chamber. Thus, the pressure transducer can remain on the first chamber, but the sample is exchanged from the first chamber to the second chamber, requiring an open channel to be provided for both chambers.

[0114] To obtain the volume of the sample, also the ambient pressure can be used. The ambient pressure can be measured, for example, by operating the valves to bring the gas receiver 159 in communication with the pressure sensor 123, 223, where the gas receiver 159 is at atmospheric pressure.

[0115] The ambient pressure can be measured, for example, by opening all valves (e.g. except the first valve 109 and / or the second valve 119 and / or the gas supply valve 179) and measuring the pressure by the pressure sensor 123, 223. To evaluate the test and obtain the sample volume, the ideal gas law can be used. Since the amount of gas molecules in the system is constant before and after expansion, the Boyle's law can be employed to calculate the unknown sample volume Vs: The unknown sample volume can (for example for the first measurement mode) be calculated as:

[0116] Vs = Vc - (Va / (P1 / P2-1)),

[0117] where P1 is the first pressure (e.g. related to the first measurement mode), P2 is the second pressure (e.g. related to the first measurement mode), Vc is the volume of the first chamber and Va is the volume of the second chamber.

[0118] The first measurement mode can be more suitable for analyzing e.g. foams. However, there can be a risk of contaminating the instrument when measuring fine powders in the first measurement mode. By using the second measurement mode, which is suitable for fine powders, the risk of contamination can be lower.

[0119] In the prior art, if the temperature of the chamber is different from the ambient temperature, introducing the measurement gas at room temperature into a different chamber during the purge step of the measurement process can disturb the thermal system. This often results in a prolonged measurement time or inaccurate results if the equilibration time is chosen too short. In the prior art, there is no control of the temperature of the gas before it is introduced into the sample chamber or the reference chamber. Typically, the gas enters the analysis chamber at ambient temperature at the time of measurement. Especially if the temperature of the chamber is different from the ambient temperature, a large amount of time is needed to equilibrate the gas, which means that in the prior art, the full advantage of thermal control cannot be fully utilized.

[0120] According to embodiments of the present invention, a conditioning chamber, a reference chamber and a sample chamber are provided, and all these volumes or chambers can share the same thermal control system and can have the same thermal insulation. The volume of the conditioning chamber can be dimensioned so that it can contain and pre-condition the full amount of gas needed for the analysis step. To improve the heat transfer from the manifold to the gas, the volume of the conditioning chamber contains a metal mesh to increase the surface area that participates in the heat transfer.

[0121] Furthermore, embodiments of the present invention also comprise arrangements that do not allow for a bidirectional measurement. These embodiments for example do not comprise the first valve 109 and / or the sixth valve 153. These embodiments for example can allow for filling the second chamber 105 first and then expanding the gas into the first chamber 103, providing the second measurement mode, whereas the first measurement mode can not be possible. The draining of the system can be performed via the valve 151 to the exhaust 159.

[0122] Other embodiments for example do not comprise the second valve 119 and / or the first valve 109. These embodiments for example can allow for filling the first chamber 103 first and then expanding the gas into the second chamber 105, providing the first measurement mode, whereas the second measurement mode can not be possible. The draining of the system can be performed via the sixth valve 153 to the exhaust 159.

[0123] Embodiments of the present invention can or can not implement two different volume measurement modes. At least one measurement mode can be supported, where for example the second chamber can be filled with gas first, which is then expanded into the first chamber.

[0124] It should be noted that the term "comprising" does not exclude other elements or steps, and the use of the article "a" or "an" does not exclude a plurality. Also individual features can be implemented as a combination of multiple features.

[0125] The embodiments of the application are not restricted to the preferred embodiments described above and shown in the drawings. Rather, various modifications are possible within the principles of the application, even if they were not explicitly described or shown in the drawings.

Claims

1. An arrangement for measuring the volume of a sample of a solid or liquid, the arrangement comprising: a first chamber for containing the sample; at least one second chamber connectable to the first chamber; a third chamber connectable to a gas supply and connected to a gas entry path leading to at least one of the first and second chambers; a pressure sensor; a plurality of gas paths including the gas entry path, the plurality of gas paths including a plurality of valves; and a temperature equilibration system configured to temperature regulate at least the first, second and third chambers to substantially the same temperature; wherein the gas paths and valves are arranged and connected to allow: filling of gas exiting the third chamber into at least one of the first and second chambers, and measuring the pressure in at least one of the first and second chambers. the temperature equilibration system comprises:

2. The arrangement of claim 1, wherein, a metal assembly in thermal contact with at least one of the first, second and third chambers and at least a portion of at least one of the gas paths and at least one of the valves. the internal volume of the third chamber is sized between 0.1 and 100 times the internal volume of one of the first and second chambers.

3. The arrangement of claim 2, wherein, the third chamber encloses a metal material providing a high surface area, wherein the metal material is in thermal contact with the metal assembly, wherein the metal material comprises at least one of: a web of fibers, a sintered structure, a fabric.

4. The arrangement of claim 2, wherein, the arrangement further comprises:

5. The arrangement of any one of claims 2 to 4, wherein, a temperature regulating device for temperature regulating the metal assembly to a desired temperature, and insulation surrounding the metal assembly. the metal assembly comprises:

6. The arrangement of claim 5, wherein, a first metal portion comprising the first chamber, a second metal portion comprising the second chamber, and a third metal portion comprising the third chamber, wherein the first metal portion is mounted to a side flat surface of the second metal portion at a side flat surface and another side flat surface of the second metal portion is mounted to a side flat surface of the third metal portion. the gas paths and valves comprise at least one of:

7. The arrangement of any one of claims 1 to 4, wherein, a first gas path comprising a first valve, the first gas path connected to the first chamber via the first valve on one end and to the gas entry path on the other end; and a second gas path comprising a second valve, the second gas path connected to the second chamber via the second valve on one end and to the gas entry path on the other end. the arrangement comprises at least one of:

8. The arrangement of claim 7, wherein, a third gas path comprising a third valve, the third gas path connected to the first chamber on one end and to the pressure sensor via the third valve on the other end; and a fourth gas path comprising a fourth valve, the fourth gas path connected to the second chamber on one end and to the pressure sensor via the fourth valve on the other end. a fourth gas path comprising a fourth valve, the fourth gas path being connected at one end to the second chamber and at the other end to the pressure sensor via the fourth valve.

9. The arrangement of claim 8, wherein, The arrangement comprises at least one of: a fifth gas path comprising a fifth valve, the fifth gas path being connected at one end to the first chamber via the fifth valve and at the other end to a gas receiver; and a sixth gas path comprising a sixth valve, the sixth gas path being connected at one end to the second chamber via the sixth valve and at the other end to a gas receiver.

10. The arrangement of claim 9, wherein, The arrangement further comprises: a controller adapted to control the state of at least one of the first valve, the second valve, the third valve, the fourth valve, thereby allowing to selectively measure the volume of the sample according to a first measurement mode or a second measurement mode, wherein in the first measurement mode the first chamber in which the sample is accommodated is filled with gas from the third chamber, and the gas is later expanded into the second chamber, wherein in the second measurement mode the second chamber is filled with gas from the third chamber, and the gas is later expanded into the first chamber in which the sample is accommodated.

11. The arrangement of claim 10, wherein, The controller is adapted to cause, when in the first measurement mode: opening the first valve and the third valve to allow filling of the first chamber with gas from the third chamber, closing the first valve and measuring a first pressure related to the first measurement mode using the pressure sensor; opening the fourth valve to allow expansion of the gas also into at least one of the second chambers and measuring a second pressure related to the first measurement mode, wherein the arrangement is adapted to calculate the volume of the sample based on the first pressure and the second pressure both related to the first measurement mode.

12. The arrangement of claim 11, wherein, The controller is adapted to cause, when in the second measurement mode: opening the second valve and the fourth valve to allow filling of the second chamber with gas from the third chamber, closing the second valve and measuring a first pressure related to the second measurement mode using the pressure sensor; opening the third valve to allow expansion of the gas also into the first chamber and measuring a second pressure related to the second measurement mode, wherein the arrangement is adapted to calculate the volume of the sample based on the first pressure and the second pressure both related to the second measurement mode.

13. The arrangement of claim 12, wherein, The controller is adapted to cause at least one of: after measuring the second pressure related to the first measurement mode, opening the fifth valve to allow draining of the gas from the first chamber and the second chamber to the gas receiver; and after measuring the second pressure related to the second measurement mode, opening the sixth valve to allow draining of the gas from the first chamber and the second chamber to the gas receiver.

14. The arrangement of claim 8, wherein, At least one of the first valve, the second valve, the third valve, the fourth valve comprises a one-way valve having a sealed input side.

15. The arrangement of claim 14, wherein, At least one of the following is applicable: The input side of the first valve faces the first chamber; The input side of the second valve faces the second chamber; The input side of the third valve faces the pressure sensor; The input side of the fourth valve faces the pressure sensor; In case the third valve is in an open state, the input side of the fourth valve is connected to the first chamber; In case the fourth valve is in an open state, the input side of the third valve is connected to the second chamber.

16. The arrangement of claim 9, wherein, The arrangement further comprises at least one of the following: a seventh gas path comprising a seventh valve and connecting the second chamber to another second chamber; and an eighth gas path comprising an eighth valve, the eighth gas path being connected on one end to the first valve, the second valve and the gas inlet path and on another end to another gas receiver.

17. The arrangement of claim 12, wherein, The arrangement further comprises: a processor adapted to calculate the volume of the sample based on at least pressure measurements and the volumes of the first chamber and the second chamber; an electronic memory accessible by the processor and containing calibration data on the volumes of the first chamber and the second chamber for use in the calculation of the volume of the sample.

18. The arrangement of claim 8, wherein, At least one of the following is applicable: The gas inlet path comprises a gas supply valve; and At least one of the first valve, the second valve, the third valve, the fourth valve comprises an electromagnetic valve configured as a two-way self-locking valve.

19. A method for manufacturing an arrangement for measuring the volume of a sample of a solid or liquid, wherein, The method comprises: providing a first chamber for containing the sample; providing at least one second chamber connectable to the first chamber; providing a third chamber connectable to a gas supply source and connected to a gas inlet path leading to at least one of the first chamber and the second chamber; providing a temperature equilibration system configured to temperature regulate at least the first chamber, the second chamber and the third chamber to substantially the same temperature; providing a pressure sensor; arranging and connecting a plurality of gas paths comprising a plurality of valves to allow for: filling gas leaving the third chamber into at least one of the first chamber and the second chamber, and measuring pressure in at least one of the first chamber and the second chamber.

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