Gravimetric measuring system

Abstract

A gravimetric measuring system (10) includes a balance (12) with a weighing chamber (22) surrounded by a weighing chamber wall (23, 24, 26, 28); an electromechanical weighing system (181) arranged in a weighing system chamber (18); an electronic control apparatus (36) for controlling the system operation; a cooling apparatus (34), controllable by the control apparatus, for cooling the weighing chamber (22); and a plurality of functional modules (14, 16) that generate heat during operation and are insertable into module receptacles (283) arranged on the weighing chamber wall (28). The module receptacles (283) have device-side thermal interface components (32a) that are thermally connected to the cooling apparatus (34), and the functional modules (14, 16) have corresponding module-side thermal interface components (32b) that, in an inserted state of the respective functional module (14, 16), thermally contact the device-side thermal interface component (32a) of the respectively associated module receptacle (283).

Claims

1. A gravimetric measuring system, comprising a balance with a weighing chamber comprising a weighing chamber wall that includes a plurality of recesses defining module receptacles arranged on the weighing chamber wall; an electromechanical weighing system; an electronic control apparatus for controlling operation of the weighting system; a cooling apparatus, which is controllable by the control apparatus, for cooling the weighing chamber; and a plurality of functional modules, which generate heat during operation and which are configured for insertion into the recesses defining the module receptacles, arranged on the weighing chamber wall; wherein the module receptacles have device-side thermal interface components, which are thermally connected to the cooling apparatus, and the functional modules have corresponding module-side thermal interface components, which in an inserted state of the respective functional module, thermally contact the device-side thermal interface component of a respectively associated one of the module receptacles to provide a connection of the respective functional module to the cooling apparatus such that the cooling apparatus dissipates heat corresponding to heat generated in the respective functional module.

2. The gravimetric measuring system as claimed in claim 1, wherein: each device-side thermal interface component has a device-side contacting area and the respective device-side contacting areas are identical to one another with respect to size, each module-side thermal interface component has a module-side contacting area and the respective module-side contacting areas vary in size between respective ones of the functional modules, and the size of each module-side contacting area is equal to or smaller than the size of the device-side contacting areas and is dependent on an average operating heat output of the respective functional modules.

3. The gravimetric measuring system as claimed in claim 2, wherein the control apparatus is programmed to control the cooling apparatus with a total cooling capacity (P) that is dependent on a type and number of the inserted functional modules.

4. The gravimetric measuring system as claimed in claim 3, wherein the sizes of the module-side contacting areas are matched with one another such that each functional module taps off an amount of cooling capacity set to compensate for an average operating heat output for the functional modules from the total cooling capacity (P), which is uniformly distributed to all of the device-side thermal interface components.

5. The gravimetric measuring system as claimed in claim 4, wherein the sizes of the module-side contacting areas are linearly dependent on the average operating heat output of the respective functional modules.

6. The gravimetric measuring system as claimed in claim 2, wherein each module receptacle has a device-side identification interface component and each functional module has a corresponding module-side identification interface component, and wherein the control apparatus is programmed to identify each functional module inserted into a respective one of the module receptacles through interaction between the respective device-side and module-side identification interface components and to control the cooling apparatus accordingly.

7. The gravimetric measuring system as claimed in claim 1, wherein the device-side thermal interface components and the module-side thermal interface components are mutually spring-loaded metal plates, and wherein one of the spring-loaded metal plates is thermally coupled to the cooling apparatus and another of the spring-loaded metal plates is thermally connected to the heat source of the functional module.

8. The gravimetric measuring system as claimed in claim 7, wherein the spring-loaded metal plates form a spring-loaded connection when the functional module is inserted into the module receptacle.

9. The gravimetric measuring system as claimed in claim 3, wherein the control apparatus increases cooling capacity for each additionally inserted functional module by a cooling amount corresponding to a heat amount for the respective additionally inserted function module.

10. The gravimetric measuring system as claimed in claim 1, wherein module receptacles which are not occupied by functional modules are closable by a panel equipped with thermal insulation such that an uncontacted device-side thermal interface component does not represent a cold source that interferes with temperature distribution in the weighing chamber.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) In the drawings:

(2) FIG. 1: is a schematic representation of a gravimetric measuring system according to the invention in the final state of assembly with an incompletely illustrated weighing chamber wall,

(3) FIG. 2: is the weighing chamber rear wall of the balance of the gravimetric measuring system from FIG. 1 in an intermediate state of assembly without inserted functional modules or panels,

(4) FIG. 3: is an incomplete sectional view of the weighing chamber rear wall of the balance of the gravimetric measuring system from FIG. 1 and adjacent areas, and

(5) FIG. 4: is a schematic representation of a preferred cooling control of the balance of the gravimetric measuring system from FIG. 1.

(6) FIG. 5: is a simple schematic representation of the spring-loaded metal plates from FIG. 3.

DETAILED DESCRIPTION

(7) Identical reference numerals and symbols in the figures indicate the same or analogous elements.

(8) FIG. 1 shows a schematic representation of a gravimetric measuring system 10 according to the invention, which consists substantially of a balance 12 and two functional modules 14, 16, inserted therein, as well as a panel 15. In the embodiment shown, the functional module, provided with the reference numeral 14, is a laser scanner unit, which is suitable for detecting bar codes; and the functional module, provided with the reference numeral 16, is a lighting unit. However, the specific functions of the functional modules 14, 16 play no role in the context of the present invention.

(9) In the embodiment shown, the balance 12 substantially comprises three regions, namely a weighing system chamber 18, in which a weighing system 181, indicated in FIG. 3, is arranged. The specific construction of the weighing system 181 does not play a role in the context of the present invention. In each case the weighing system 181 comprises a load receptacle (not shown separately), which is connected to a sample carrier 20, which in turn is arranged in a weighing chamber 22, adjoining the weighing system chamber 18 in the embodiment shown. The weighing chamber 22 is surrounded by a weighing chamber wall, which is shown only incompletely in FIG. 1. In particular, the weighing chamber base 24, through which the sample carrier 20 extends, a weighing chamber side wall 26 and a weighing chamber rear wall 28, all of which will be described in greater detail below, are illustrated. In the representation in FIG. 1, the weighing chamber rear wall 28 is covered substantially by the front sides of the functional modules 14, 16 and the panel 15, which is arranged between these functional modules 14, 16. Typically the weighing chamber walls also comprise an additional weighing chamber side wall, a weighing chamber front wall and a weighing chamber cover 23 (indicated only in FIGS. 2 and 3), but none of these are shown in FIG. 1 for reasons of better clarity.

(10) Furthermore, the balance 12 comprises an electronic unit 30, which in the case of the embodiment shown comprises essentially a large format display. The electronic unit 30 can additionally contain a control apparatus, which will be explained in more detail below. However, this control apparatus can also be arranged at another location of the balance 12. It is considered to be advantageous if this control unit is arranged so as to be thermally insulated from the weighing system chamber 18 and from the weighing chamber 22.

(11) FIG. 2 shows a frontal view of the weighing chamber rear wall 28, but without the inserted functional modules 14, 16 and without the panel 15. FIG. 3 shows a sectional view of the weighing chamber rear wall 28 and adjoining regions of the balance 12, although the illustration of FIG. 3 also shows the inserted functional modules 14, 16 and the inserted panel 15. Despite this difference an integrated view of FIGS. 2 and 3 makes it easier to understand the following description.

(12) The weighing chamber rear wall 28 is constructed of vertical posts 281 and struts 282, arranged transversely thereto. Between these, there extend recesses 283, which are also referred to herein as module receptacles 283. On the weighing system chamber side, the weighing chamber rear wall 28 has an end wall 284, which seals the weighing system chamber 18 and which prevents access through the module receptacles 283 into the weighing system chamber 18. In the illustrated embodiment the end wall 284 is at the same time the front wall of the weighing system chamber 18.

(13) The module receptacles 283 serve to house in a spatially adapted manner the functional modules 14, 16. The embodiment according to FIGS. 1 and 3 has no functional module is inserted into the central module receptacle 283 in FIGS. 2 and 3. Instead, this recess 283 between the posts 281 and struts 282 is closed off with the panel 15 towards the weighing chamber. The module receptacles 283 are designed identically with respect to their configuration, as will be described in greater detail below, so that the functional modules 14, 16 can be inserted just like other, compatibly designed functional modules into each of the module receptacles 283. With regard to their size the module receptacles 283 are designed preferably identically, in particular so that they merge into each other, and preferably without a separating element. This permits the functional modules 14, 16, the size of which corresponds to an integer multiple of a unit size, can be inserted so as to fit exactly into one or more adjacent module receptacles 283. It is also feasible that the sizes of the module receptacles 283 themselves are different integer multiples of a unit size. The same applies to the panels 15 as to the functional modules 14, 16.

(14) Each module receptacle 283 has a device-side identification interface component 30a, which can interact with a corresponding module-side identification interface component 30b of an inserted functional module 14, 16, in order to identify the inserted functional module 14, 16 and to connect it to a control unit through a corresponding data line (dashed lines).

(15) Furthermore, each module receptacle 283 has a device-side thermal interface component 32a, which is in thermal contact with a corresponding module-side thermal interface component 32b of an inserted functional module 14, 16. The device-side thermal interface components 32a are thermally connected (dotted lines) to one another and to a cooling apparatus 34, as depicted in FIG. 4.

(16) Although additional interfaces, such as, for example, electrical and electronic, in particular, data interfaces, for controlling the functional modules 14, 16 are preferably provided, they are not shown in the figures for the sake of clarity.

(17) A special feature of the module-side thermal interface components 32b of the illustrated embodiment lies in the fact that in comparison to the device-side thermal interface components 32a and to one another, they have different contacting area sizes. All of the module-side thermal interface components 32b are smaller than or at most just as large as the device-side thermal interface components 32a that are identical to one another with respect to size. The specific size of the module-side contacting areas depends on the heat output of the respective functional modules 14, 16. In particular, there can be a proportionality between the heat output and the size of the thermal contact area of the modules.

(18) FIG. 4 shows a preferred embodiment of a control of the balance 12. Shown are the device-side thermal interface components 32a, which are thermally connected to one another and to a cooling apparatus 34, and the device-side identification interface components 30a, which are identified here in each case with the index i. The identification data, obtained through interaction between the device-side and module-side identification interface components 30a, b, are transmitted to a control apparatus 36, and there, in particular, to the identification unit 361. In the embodiment shown in FIGS. 1 and 3, the identification interface i=1 would provide the information about the inserted lighting module 16. The identification interface i=2 would provide the information about the absence of an inserted functional module; and the identification interface i=3 would provide the information about the inserted laser scanner module 14. The identification can be carried out in a manner specific to the type of module or even in a manner specific to the individual module. The identification data are sent from the identification unit 361 to a central unit 362. The latter receives information about the specific heat outputs of the identified functional modules 14, 16 from a memory unit 363. As indicated by the dotted and dashed line, the memory unit 363 can be integrated in the control apparatus 36 or can be made available remote therefrom, for example, in a server, connected through the Internet. However, this information can also be stored in a memory unit of the functional module itself. In particular, it can be provided that after the functional module has been produced, said functional module is run through an individual measurement of its heat output at the factory in the context of the quality control, the result of which measurement is then stored in the memory unit. A type specific storage without individual measurement is also possible. In any case the storage of the information in the module itself combines the advantages of reducing the load on the balance control unit, the independence of external data sources and the possibility of customization.

(19) From the identification data, on the one hand, and the heat output data, on the other hand, the central unit 362 calculates the default values for controlling the cooling apparatus 34; and then said default values are passed on to a cooling control unit 364, connected to the cooling apparatus. In the illustrated embodiment the predetermined cooling capacity P.sub.st corresponds to a static cooling capacity, which is derived from the sum of the individual heat outputs P.sub.mi of the identified functional modules 14, 16, in each case multiplied by a weighting factor c.sub.i:P.sub.st=.sub.i c.sub.t P.sub.mi. In this case the total cooling capacity P is obtained as a sum of a module-independent basic cooling capacity P.sub.0 (not mentioned in FIG. 4) and the module-dependent static cooling capacity P.sub.st:P=P.sub.0+P.sub.st+P.sub.v.

(20) The weighting factor c.sub.i can be used, for example, to take into account the specific position, i.e., the specific module receptacle, in which a functional module 14, 16 is inserted. Such a weighting can also be dispensed with; in other words, the weighting factor corresponds then to 1 and/or is identical in all summands.

(21) This static cooling capacity P.sub.st is uniformly distributed from the cooling apparatus 34 to all of the device-side thermal interface components 32a. The respective, requirement specific distribution to the functional modules 14, 16 takes place as a result of the different sizes of the module-side thermal interface components 32b.

(22) In a further development of this cooling control, the static cooling capacity P.sub.st forms only one of a plurality of terms of the total cooling capacity P:P=P.sub.0+P.sub.st+P.sub.v, where P.sub.v=P.sub.v(T). In this embodiment, in addition to the static cooling capacity P.sub.st, there is also provided a small, regulated cooling capacity contribution, the cooling capacity correction P.sub.v, with which it is possible to compensate for small fluctuations of the temperature T in the weighing chamber 22.

(23) The embodiments, discussed in the specific description and shown in the figures, represent only illustrative exemplary embodiments of the present invention. In light of the disclosure herein, the person skilled in the art is given a broad spectrum of possible variations. In particular, it is possible, as an alternative or in addition to the weighing chamber rear wall 28, to design one or more of the remaining walls of the weighing chamber wall in the manner described as a post/strut structure with recesses, designed as module receptacles. In such cases, in which the module receptacles do not adjoin a chamber to be sealed, in particular, for reasons of calibration, a special sealing wall, as in the embodiment shown here, is not necessary.

LIST OF REFERENCE NUMERALS AND SYMBOLS

(24) 10 Gravimetric measurement system 12 Balance 14 Functional module 15 Panel 16 Functional module 18 Weighing system chamber 181 Weighing system 20 Sample carrier 22 Weighing chamber 23 Weighing chamber cover 24 Weighing chamber base 26 Weighing chamber side wall 28 Weighing chamber rear wall 281 Post 282 Strut 283 Recess/module receptacle 284 End wall 30a/b Device-side/module-side identification interface component 32a/b Device-side/module-side thermal interface component 34 Cooling apparatus 36 Control apparatus 361 Identification unit 362 Central unit 363 Memory unit 364 Cooling control unit P Total cooling capacity P.sub.0 Basic cooling capacity P.sub.v Cooling capacity correction c.sub.i Weighting factor P.sub.mi Module-specific heat output T Temperature (in the weighing chamber) I.sub.n Insulation