Sealing label for sealing measuring devices to protect against tampering, and measuring device protected against tampering by means of sealing

Abstract

The invention relates to a sealing label comprising: a cover layer (1) and an adhesive layer (2), the cover layer (1) and the adhesive layer (2) forming a substantially planar sealing body (3); wherein the sealing body (3) is designed to adhere, by means of the adhesive layer (2), to an object to be secured; wherein the sealing body (3) has at least one hole (4); wherein the at least one hole (4) has an area that is one tenth to one quarter of the area of the sealing body (3); wherein the at least one hole (4) is positioned in the sealing body (3) in such a way that at least one subarea (5), in particular a predetermined breaking point, is formed which, at its narrowest point, is no wider than 2 mm, preferably no wider than 0.5 mm.

Description

[0001] Sealing label for sealing measuring instruments to protect against tampering, measuring instrument protected against tampering by sealing

[0002] The invention relates to a seal label that is applied to a measuring device in industrial measurement and automation technology suitable for use in legal metrology to protect against tampering. Furthermore, the invention relates to a measuring device in industrial measurement and automation technology that is protected against tampering and suitable for use in legal metrology.

[0003] In process and automation technology, water and

[0004] In the wastewater industry, and among other things in chemical or process engineering processes, measuring instruments are used which are subject to calibration in order to ensure compliance with legal calibration regulations, in particular the calibration error limits according to the Measurement and Calibration Act, and which must be calibrated at regular intervals.

[0005] Such measuring devices can be actuator field devices, for example electronic engine or valve controls, or also sensor field devices, namely measuring devices such as Coriolis mass flow meters, vibronic density meters, magnetic-inductive flow meters, vortex flow meters, ultrasonic flow meters, thermal mass flow meters, pressure measuring devices, level measuring devices, vibronic level limit switches, temperature measuring devices, pH value measuring devices, etc., which are each used to determine measured values ​​representing a physical and / or chemical measured variable that varies over time within a predetermined measuring range and to generate at least one digital or analogue measured value signal that transmits the same measured values ​​externally to the respective measuring device.

[0006] In a measuring device subject to legal metrology, the measured variable to be recorded can be, for example, a mass flow, a density, a viscosity, a fill or limit level, a pressure, a pH value, an electrical conductivity, or a temperature of a liquid, powder, vapor, or gaseous medium that is conveyed or stored in a corresponding container, such as a pipeline or tank. Such electronic measuring devices designed as measuring devices, known to those skilled in the art, are offered commercially by the applicant itself, for example, under the names t-trend ATT12, Promag W / P 300 / 400 / 500 / 800, Promass F / O / X / Q 300 / 500, and Prosonic E 100.

[0007] Measuring instruments subject to custody transfer, for example, which are part of a custody transfer system, must be checked before commissioning to ensure that the required measurement accuracy or that stated in the specification is reliably achieved. Such checks of measuring instruments subject to custody transfer also take place after commissioning and at regular intervals, for example, at the request of the user operating the device and / or at the request of an authority supervising the measuring point established using the electronic device.

[0008] Modifications to legally required measuring instruments intended to achieve the required measurement accuracy are generally not permitted or even impossible while they are operating in normal measuring mode. Instead, the measuring instrument is transferred to a legal metrology facility under the supervision of a certified or officially appointed inspector. The inputs required for modifying the measuring instrument can be made, for example, via a corresponding control element.

[0009] Tampering with a measuring instrument subject to legal metrology is defined as unauthorized modification by unauthorized personnel. To prevent tampering or detect it as early as possible, protective measures against unauthorized access are provided. Such protective measures often consist of a switch that can only be activated after opening a housing, which can optionally put the measuring instrument into legal metrology mode. In this case, the housing is usually protected against undetected access by a label or seal.

[0010] It is less common to attach sealing labels to the switch inside the housing of the measuring device.

[0011] The document DE102013109096A1 teaches a measuring device subject to calibration that is protected against unauthorized or undetected tampering. For example, an adhesive seal label attached to the switch and / or the housing initially prevents the housing from being opened or the switch from being activated. For some devices, it is important that the housing is directly accessible, for example, in battery-operated devices for replacing the batteries. This requires more sophisticated protective measures that allow the device's batteries to be replaced, so that, for example, the housing seal can be broken and, if necessary, restored without compromising the seal label protecting the switch.

[0012] The document KR20200050038A teaches a conventional seal label, which in this case conceals a DIP switch mounted on a circuit board and can set electronics to either an access authorization or a sealing mode. The seal label in question makes unauthorized access to the circuit board detectable by leaving behind recognizable residue when removed.

[0013] Seal labels can indicate tampering by being visibly destroyed when removed.

[0014] Visible destruction can occur automatically when the seal label is removed from the object to be secured if the force required to remove the seal label is greater than the force required to tear the seal label or parts of it.

[0015] A known problem is that a conventional sealing label does not adhere well to the housing of a field device according to the state of the art and therefore cannot indicate that tampering has occurred.

[0016] The invention is based on the object of providing a sealing label that can be reliably adhered to a switch within a housing and that cannot be removed without destruction.

[0017] The invention solves the problem by a sealing label according to independent claim 1.

[0018] The sealing label according to the invention comprises a cover layer and an adhesive layer; wherein the cover layer and the adhesive layer form a substantially planar sealing body; wherein the sealing body is designed to adhere to an object to be secured by means of the adhesive layer; wherein the sealing body has at least one hole; wherein the at least one hole comprises an area that is one-tenth to one-quarter of the area of ​​the sealing body; wherein the at least one hole is arranged in the sealing body in such a way that at least one partial area, which in particular comprises a predetermined breaking point, is created, which at the narrowest point is not wider than 2 mm, preferably not wider than 0.5 mm.

[0019] In one embodiment of the invention, the sealing body has at least one partial surface which tears when the sealing body is tensioned with a force of more than 1 N according to FINAT test method FTM 1 (300 mm / min) in a direction which is parallel to the surface of the sealing body.

[0020] In one embodiment of the invention, the sealing label comprises a mounting tab connected to the sealing body; a perforation extending between the sealing body and the mounting tab; wherein the mounting tab is suitable for positioning the sealing body; wherein the perforation is configured to separate the mounting tab from the sealing body without damaging the sealing body; wherein, after the separation of the mounting tab, it is clearly visible from the perforation where the mounting tab was separated.

[0021] One embodiment of the invention comprises several, in particular four, uniform, rectangular holes.

[0022] In one embodiment of the invention, the sealing body has a rectangular, in particular square, base area; the base area has side lengths that are between 5 and 15 mm long.

[0023] In one embodiment of the invention, the cover layer and the adhesive layer are part of an adhesive film; wherein the adhesive film is suitable for cutting with a laser; wherein the adhesive film is not thicker than 0.3 mm overall, preferably not thicker than 0.1 mm; wherein the adhesive film tears if one of its lengths is increased by stretching by 2% to 10%; wherein the adhesive film changes its adhesive strength by no more than 20% and its tear strength by no more than 20% at temperatures between -40 degrees Celsius and 80 degrees Celsius.

[0024] In one embodiment of the invention, the adhesive layer comprises acrylate adhesive; wherein the adhesive layer is between 0.01 and 0.2 mm thick; wherein the adhesive layer has an adhesive force according to FINAT test method FTM 1 (300 mm / min) of between 7 and 35 N, at room temperature and on steel (stainless), polycarbonate and polypropylene.

[0025] A calibrated measuring device according to the invention, configured to detect a process measurement variable, comprises: a switch having at least one switching element, with a base body defining a smooth reference surface; at least one unevenness on the base body, the contours of which deviate from the smooth reference surface; a sealing label according to the invention, which is glued to the base body; wherein the sealing body covers the at least one switching element; wherein the sealing body has at least one - preferably rectangular - hole for each of the at least one unevenness of the base body; wherein the sealing body has one or more holes, each surrounding at least one of the unevenness.

[0026] In one embodiment of the calibrated measuring device, the unevennesses are projections or depressions; wherein the sealing body has one or more holes through which at least one of the projections of the sealing body protrudes, or which each surround at least one of the depressions.

[0027] The invention has the advantage that the adhesive surface of the sealing label according to the invention is adapted to the adhesive surface of an object to be sealed, for example a switch within a housing, in such a way that, on the one hand, the proportion of the adhesive surface of the sealing label is maximized, and, on the other hand, the force required to tear parts of the sealing label is minimized. Another advantage is that the sealing label can be produced quickly and cost-effectively on commercially available films, for example 3M films, including by laser cutting. Another advantage is that commercially available films can meet the necessary material requirements, which are given, for example, by the large temperature fluctuations and / or vibrations within a housing of a field device. Another advantage is that the sealing label can be positioned particularly well on a switch thanks to the mounting tab.Another advantage is that the seal label can be attached to common DIP switches.

[0028] The invention is explained with reference to the following figures.

[0029] It shows:

[0030] Fig. 1 : a plan view of an embodiment of the sealing body 3 with holes 4 and mounting tab 6.

[0031] Fig. 2: a plan view of a switch 8 sealed by an adhesively bonded configuration of the sealing body 3.

[0032] Fig. 3: a plan view of a design of a switch 8 which can put a measuring instrument subject to calibration into calibration and measuring mode.

[0033] The design of the sealing label shown in Fig. 1 shows the sealing body 3 with four rectangular holes, with the narrow partial areas 5 that can be torn with little effort. The mounting tab 6 together with the sealing body 3 forms the sealing label, the perforation 7 forms a dividing line between the mounting tab 6 and the sealing body 3 and enables their separation.

[0034] Fig. 2 shows an embodiment of a switch 8 sealed with the sealing label according to the invention, having four projections 11, labeled "1," "2," and "ON," which protrude beyond the sealing body 3 due to the four holes 4. The sealing body 3 adheres to the base body 10 of the switch 8 (and covers the switching element 9, not visible here).

[0035] Fig. 3 shows a configuration of a switch 8 configured to put a measuring device subject to calibration into calibration and measurement mode. The switch 8 consists of a base body 10 with four protruding projections 11 and two switching elements 9 that are movable relative to the base body 10. List of reference symbols

[0036] 1 top layer

[0037] 2 adhesive layer

[0038] 3 Seal body 4 Hole in the seal body

[0039] 5 partial surfaces of the seal body

[0040] 6 mounting tab

[0041] 7 Perforation

[0042] 8 Switch 9 Switching element

[0043] 10 basic bodies

[0044] 11 bumps

Claims

Patent claims 1. A seal label comprising: • a covering layer (1 ); • an adhesive layer (2); • wherein the cover layer (1) and the adhesive layer (2) form a substantially planar sealing body (3); • wherein the sealing body (3) is designed to adhere to an object to be secured by means of the adhesive layer (2); • wherein the sealing body (3) has at least one hole (4); • wherein the at least one hole (4) comprises an area which is one tenth to one quarter of the area of ​​the sealing body (3); • wherein the at least one hole (4) is arranged in the sealing body (3) in such a way that at least one partial area (5), in particular a predetermined breaking point, is created which is not wider than 2 mm, preferably not wider than 0.5 mm, at the narrowest point.

2. A seal label according to claim 1, • wherein the sealing body (3) has at least one partial surface (5) which tears when the sealing body (3) is tensioned with a force of more than 1 N according to FINAT test method FTM 1 (300 mm / min) in a direction which is parallel to the surface of the sealing body (3).

3. Sealing label according to one of claims 1 or 2, further comprising: • a mounting tab (6) connected to the sealing body (3); • a perforation (7) running between the sealing body (3) and the mounting tab (6); • wherein the mounting tab (6) is suitable for positioning the sealing body (3); • wherein the perforation (7) is designed to separate the mounting tab (6) from the sealing body (3) without damaging the sealing body (6); • after the mounting tab (6) has been separated, it is clearly visible from the perforation (7) where the mounting tab (6) has been separated.

4. Sealing label according to one of claims 1 to 3, further comprising: • several, in particular four, uniform, rectangular holes (4).

5. Sealing label according to one of claims 1 to 4, further comprising: • a rectangular, in particular square, base area; • where the base area has sides that are between 5 and 15 mm long.

6. Sealing label according to one of claims 1 to 5, • wherein the cover layer (1) and the adhesive layer (2) are part of an adhesive film; • wherein the adhesive film is suitable for cutting with a laser; • the adhesive film is not thicker than 0.3 mm in total, preferably not thicker than 0.1 mm; • the adhesive film tears when one of its lengths is increased by stretching by 2% to 10%; • the adhesive film does not change its adhesive strength by more than 20% and its tear strength by more than 20% at temperatures between -40 degrees Celsius and 80 degrees Celsius.

7. Sealing label according to one of claims 1 to 6, • wherein the adhesive layer comprises acrylate adhesive; • the adhesive layer being between 0.01 and 0.2 mm thick; • the adhesive layer has an adhesive force according to FINAT test method FTM 1 (300 mm / min) of between 7 and 35 N, at room temperature and on steel (stainless), polycarbonate and polypropylene.

8. Calibrated measuring instrument, designed to record a process measurement, comprising: • a switch (8) with at least one switching element (9), with a base body (10) defining a smooth reference surface; • At least one unevenness (11) on the base body (10) whose contours deviate from the smooth reference surface; • a sealing label according to one of claims 1 to 7, which is glued to the base body (10); • wherein the sealing body (3) covers the at least one switching element (9); • wherein the sealing body (3) has at least one -preferably rectangular- hole (4) for each of the at least one unevenness (11) of the base body (10); • wherein the sealing body (3) has one or more holes (4) which each surround at least one of the unevennesses (11).

9. Calibrated measuring device according to claim 8, • wherein the unevennesses (11) are projections or depressions; • wherein the sealing body (3) has one or more holes (4) through which at least one of the projections of the sealing body (3) protrudes, or which surround at least one of the depressions.

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