TAMPER-PROOF SENSOR FOR A CONTAINER

Abstract

A tamper-proof sensor is adapted to be mounted on or in an opening of a container and to detect a process variable in a container. The sensor has a securing device which is designed to detect or prevent the sensor from being removed from the opening of the container.

Claims

1. A tamper-proof sensor arrangement, comprising: an electronics unit including: a sensor configured to be mounted on or in an opening of a container, the sensor being configured to detect a process variable in the container and a housing configured to house the sensor; and a securing device configured to detect or prevent the sensor from being removed from the opening of the container.

2. The sensor arrangement of claim 1, wherein the electronics unit further includes: a power supply unit providing electrical power supply to the electronics unit; a communication unit; and an antenna, wherein the power supply unit, the communication unit, and the antenna are housed in the housing.

3. The sensor arrangement according to claim 1, further comprising: a container lid having a downward angled lateral edge with a first inner thread configured to screw the container lid onto the container.

4. The sensor arrangement of claim 3, wherein the securing device is an eyelet on the lateral edge of the container lid, the eyelet being configured to permit a seal of the container to be passed therethough or attached thereto.

5. The sensor arrangement of claim 3, wherein the container lid includes a fastening arrangement on an underside thereof, the fastening arrangement configured to secure the housing thereto.

6. The sensor arrangement of claim 5, wherein the housing is attached to the fastening arrangement via a screw, a second inner thread, a bayonet lock, a snap-in device, or a further fastening arrangement.

7. The sensor arrangement of claim 5, wherein the container lid has an orifice extending from the underside to a surface thereof having a radius configured to insert a portion of the housing therein, the housing being configured to receive a tool to screw the housing through the orifice.

8. The sensor arrangement of claim 7, wherein the housing includes a bulge extending radially outward therefrom, the bugle positioned to prevent screwing of the housing into the orifice so that an upper side of the housing aligns with the surface of the container lid.

9. The sensor arrangement of claim 7, wherein the housing includes a structure extending radially outward from an upper side of the housing, the structure being configured to receive the tool to screw the housing through the orifice of the container lid into the fastening arrangement.

10. The sensor arrangement of claim 9, wherein the fastening arrangement includes a second inner thread.

11. The sensor arrangement of claim 5, wherein the securing device includes an arrangement on the fastening arrangement configured to receive the housing, the arrangement being adapted to prevent unscrewing of the housing or to break visibly when the housing is unscrewed.

12. The sensor arrangement of claim 7, wherein the securing device is a safety cover cap attached to an upper side of the housing above the orifice of the container lid and configured to break visibly when removed.

13. The sensor arrangement of claim 5, wherein the securing device includes at least one barb, the at least one barb configured to extend radially outward from the housing at a predetermined angle when the housing is completely screwed into the fastening arrangement.

14. The sensor arrangement of claim 3, wherein the container lid includes a sealing arrangement attaching the container lid to the opening of the container

15. The sensor arrangement of claim 3, wherein the housing is closed and integrally connected to the container lid.

16. The sensor arrangement of claim 1, wherein the sensor is a level sensor.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0026] In the following, examples of the disclosure are described in detail with reference to the enclosed figures. Neither the description nor the figures shall be interpreted as restricting the disclosure.

[0027] FIG. 1 shows a first example with one sensor with the top of the container lid closed,

[0028] FIG. 2 shows a second example with a sensor with a closed housing that is integrally connected to the container lid,

[0029] FIG. 3 shows a third example of a sensor with an open top of the container lid for screwing in the sensor from below,

[0030] FIG. 4 shows a fourth example of a sensor with an open top of the container lid for screwing in the sensor from above,

[0031] FIG. 5 shows a fifth example of a sensor with a cover cap,

[0032] FIGS. 6a and 6b show a sixth example of a sensor with a barb.

[0033] The drawings are only schematic and not to scale. In principle, identical or similar parts are marked with the same reference marks.

DETAILED DESCRIPTION

[0034] FIG. 1 shows in a first example of a sensor 100, for example a level sensor, which for example has a container lid 111 and an electronics unit comprising a radar sensor 121, a power supply unit 123, a communication unit 122 and an antenna 125. The electronics unit is surrounded by a housing 150. The housing 150 can be screwed from the inside by means of a structure, e.g. a thread 110, into a container lid 111, which can be secured with a seal through the eye 120. The sensor 100 with container lid 111 can be screwed onto the container together with the screwed-in electronics unit by means of a first thread 105, which is the container lid inner thread 105. The sealing of the lid 111 is achieved by the sealing arrangement 145, e.g. a sealing ring, which runs in a channel as shown in FIG. 1 and is pressed all the way round to the edge of the container when the lid 111 is screwed in. Since the lid 111 has no opening in the screw-in area of the housing 150, no additional seal is required there. After the lid 111 with screwed-in housing 150 has been screwed to the container and sealed, the sensor 100 and the housing 150 with the electronics unit cannot be removed from the container without breaking the seal. An opening of the container and thus a possible contamination of the container or the medium is also visible by breaking the seal.

[0035] FIG. 2 shows another example of a sensor 200, in which a sealable container lid 211 and the housing 150 with the electronics unit form a single unit. The housing 150 of the electronics unit 201 and the lid 211, for example, are made in one piece from high-density polyethylene (HDPE) by injection molding in conjunction with a joining process such as welding. In this example, the electronics unit 201 cannot be removed separately, but only together with the lid. However, opening the lid 111 including the electronics unit 201 can be detected by the seal.

[0036] FIG. 3 shows a sensor 300 in a further example, which can be screwed into an opening 315 of a sealable lid 311 from the inside of the lid in the direction 330 shown. In the area of the outer diameter 313, the sensor 300 has a geometrical housing shape for this purpose to accommodate a tool (e.g. an outer hexagon) to facilitate screwing into the container lid 311. Due to a bulge 312 with an enlarged outer diameter 312 at the end of the thread, it is not possible to unscrew the sensor in direction to the outside of the container 330. The sealing ring 320 along the bulge 312 is pressed against the thread structure 310 when screwed in, so that the container can be closed tightly.

[0037] FIG. 4 shows a sensor 400 in a further example, in which the sensor top has a structure 430 for holding a tool. The tamper-proof sensor 400 can be screwed into a container opening 415 from the outside of the container 440 using a tool and secured against unscrewing by means of a locking device 410 on the inside of the container/lid. This can be a lock nut, for example, which can have an additional securing device such as a grub screw as clamping screw 420. This means that it is not possible to unscrew the sensor 400 from the outside of the container with a suitable tool, such as a 2-inch bunghole wrench, despite the correspondingly shaped housing with the structure 430.

[0038] FIG. 5 shows a sensor 500 according to a further example, which has a correspondingly shaped housing with a structure 430 to accommodate a tool. A snap-on cover cap 520 or hood effectively prevents the attachment of a tool. Removing the cover cap will destroy it, so that it cannot be put back on. The cover cap 520 may, for example, have hooks that tear off when opening or removing the cover cap 520, or may be released via a predetermined breaking point. This means that any manipulation can be seen afterwards, so that appropriate measures can be taken.

[0039] Due to the presented sensor arrangement, it can be detected by the securing device according to the embodiment whether the container with the sensor has been unscrewed or whether the sensor has been screwed out of the container lid. In other embodiments, unscrewing the sensor from above or from the outside is prevented or access is completely prevented.

[0040] Due to the fact that the sensor can be screwed completely or almost completely into the container lid due to its shape, or does not or only slightly protrude at the top, or is even completely integrated into the container lid, it is possible that several containers can be stacked on top of each other, for example.

[0041] FIGS. 6a and 6b show a sensor 600 according to another example. While screwing into the thread 310 (FIG. 6a), one or more barbs 610, which are distributed along the circumference, are pressed against the outer housing wall 615 of the sensor. As soon as the sensor is completely screwed into the thread (FIG. 6b), the barbs, which are under mechanical tension, fold out of 620 and prevent them from being unscrewed again, similar to the spring folding mechanism of a cavity dowel.

[0042] This provides a tamper-proof sensor for detecting process variables in a container and a container lid, which are designed in such a way that manipulation is prevented or at least can be detected.