Detection device

Abstract

The invention refers to a detection device (200) for gaseous media (18), in particular a gaseous medium (18) for tempering sensitive, in particular perishable goods (16), said detection device (200) comprising at least one sensor head (210a, 210b, 210c) provided with an electronic circuit (250) comprising at least one sensing element (280) detecting content or parameters of said gaseous medium, such as temperature, humidity, oxygen or carbon dioxide content, the detection device (200) has the at least one sensor head (210a, 210b, 210c) releasably held in position by a sensor hub unit (202), and the electronic circuit (250) of the at least one sensor head (210a, 210b, 210c) is provided with at least one first wireless communication unit (254) for wireless communication with at least one second wireless communication unit (264) arranged in the hub unit (202) for transmitting electric power from said hub unit (202) to said sensor head (210a, 210b, 210c) and / or transmitting data generated by said electronic circuit (250) from said sensor head (210a, 210b, 210c) to said hub unit (202).

Description

[0001] Detection Device

[0002] The invention refers to a detection device for gaseous media, in particular a gaseous medium for tempering sensitive, in particular perishable goods, said detection device comprising at least one sensor head provided with an electronic circuit comprising at least one sensing element detecting content or parameters of said gaseous medium.

[0003] Such detection devices are usually using the sensor heads under harsh conditions, such as for example temperature and humidity cycles, mechanical vibrations and corrosive conditions which have a significant impact on the sensor reliability.

[0004] Therefore, it is the object of the present invention to improve the reliability of the sensors of such a detection device.

[0005] This object is solved by a detection device having the at least one sensor head releasably held in position by a sensor hub unit, that the electronic circuit of the at least one sensor head is provided with at least one first wireless communication unit for wireless communication with at least one second wireless communication unit arranged in the hub unit for transmitting electric power from said hub unit to said sensor head and / or transmitting data generated by said electronic circuit from said sensor head to said hub unit.

[0006] The fact that said sensor head is held by said hub unit enables easy positioning of said sensor head by avoiding the necessity of fixing the sensor head itself due to the fact that only the hub unit needs to be fixed and the releasable fixing of said sensor head by said hub unit enables easy exchange of said sensor head and further the wireless communication between the sensor head and the hub unit provides a reliable powering of said sensor head and data transfer which can hardly be affected by the aforementioned harsh conditions under which the sensor head has to be used. It is of particular advantage if the sensor head comprises a sensor housing enclosing the electronic circuit and admitting access of said gaseous medium to said sensing element.

[0007] Such a sensor housing has the advantage that it enables enclosing the electronic circuit together with the sensing element and protects the electronic circuit and the sensor element and further by admitting access of said gaseous medium to said sensor element enables proper detection of the content and the parameters of said gaseous medium without the need of full exposure of said sensing element to the surrounding.

[0008] In particular the electronic circuit in said sensor head is protected against any medium entering the sensor housing by a protection layer.

[0009] In particular the sensor housing is merely admitting access of gaseous medium to said sensing element and for example not of any particles or water or any other media transported by said gaseous medium.

[0010] Access for said gaseous medium can be easily obtained if the sensor housing comprises at least one access opening for said gaseous medium, whereas said access opening is kept small enough in order to avoid entry of any other solid matter transported by said gaseous medium.

[0011] In particular it is of advantage if the at least one access opening is covered by a membrane because such a membrane can be used to prevent any condensed medium to enter said sensor housing, so that said sensor housing is tight against any condensed medium.

[0012] In particular said membrane can be made of PTFE so that only gaseous components of said gaseous medium and in particular no water or other condensed media can penetrate the membrane and enter the housing for access to the sensing element. For easy assembly of the sensing element, it is of advantage if the electronic circuit is arranged on a circuit board arranged in the interior space of the sensor housing.

[0013] In this case the circuit board enables to arrange all components of the electronic circuit thereon, e.g., the first wireless communication unit and the at least one sensing element thereon for proper positioning within said sensor housing.

[0014] In order to further protect the sensing element, it is of advantage if a sensing area of said sensing element is covered by a membrane.

[0015] This additional membrane can be for example the same kind of membrane as the one covering the access opening of the sensor housing, in particular PTFE.

[0016] Such additional membrane provides further protection of said sensing area of said sensing element against undesired in particular condensed matter.

[0017] With respect to the various detecting capabilities of the sensing element it is of advantage if said electronic circuit of said at least one sensor head comprises a sensing element detecting humidity.

[0018] Another advantageous solution provides that said electronic circuit of said at least one sensor head comprises a sensing element detecting temperature.

[0019] Another advantageous solution provides that said at least one sensor head comprises a sensing element detecting CO2.

[0020] Another advantageous solution provides that said at least one sensor head comprises a sensing element detecting oxygen.

[0021] Since these sensing elements can be influenced by other components of the electronic circuit arranged on the circuit board it is of advantage, if said at least one sensing element is arranged on a portion of the circuit board significantly thermally decoupled from the other elements of the electronic circuit.

[0022] With such a solution the thermal influence of the components of the electronic circuit except the electronics on the sensing element can be avoided.

[0023] One solution of particular advantage provides that in the CO2 sensor head said CO2 sensing element, said humidity sensing element and said temperature sensing element are together arranged on a portion of the circuit board significantly thermally decoupled from the rest of the circuit board.

[0024] According to this solution the CO2 sensing, the humidity sensing and the temperature sensing are thermally decoupled from the rest of the electronic circuit and on the other hand detect the same parameters and conditions of the content of that gaseous medium at the same location and at the same time.

[0025] Another solution of particular advantage provides that in the oxygen sensor head said oxygen sensing element is arranged on a portion of the circuit board significantly thermally decoupled from the rest of the circuit board.

[0026] In order to enable the electronic circuit to generate data concerning the content and / or parameters of the gaseous medium detected by said sensing elements, said electronic circuit comprises an evaluation circuit which generates sensor data from signals of the respective sensing element.

[0027] A particular advantageous solution provides that the evaluation circuit is detecting the signals of the CO2 sensing element, the humidity sensing element and the temperature sensing element and generates CO2 data compensated by the detected humidity and detected temperature.

[0028] This solution has the advantage that the signals of the CO2 sensing element can be immediately compensated by the detected humidity and temperature of the same gaseous medium the CO2 of which is sensed.

[0029] For example, in one embodiment of the invention one first wireless communication unit together with one second communication unit is provided for the transfer of energy whereas another first communication unit together with another second communication unit is provided for the transfer of data.

[0030] It is of particular advantage if one first communication unit and one second communication unit are provided for both, the transfer of energy and the transfer of data.

[0031] In order to enable to control the sensor head via the hub unit it is of advantage that the communication units are able to transmit data from said hub unit to said sensor head.

[0032] In particular the wireless communication units are provided with antenna elements having a design, for example a flat design, so that they can be arranged in close vicinity for optimized communication.

[0033] Additionally, and / or alternatively to the various features of the present invention explained before a further version of the present invention provides that said hub unit comprises a mounting receptacle for releasably receiving the at least one sensor head.

[0034] Advantageously it is provided that the mounting receptacle receives a mounting section of the sensor housing of the respective sensor head which mounting section can be adapted to the mounting receptacle.

[0035] In particular the mounting section of the sensor housing of the sensor head received by the mounting receptacle is arranged opposite to the sensor section of the sensor housing receiving the sensing element. This design has the advantage that the sensor section with the sensing element received therein can be easily exposed to the gaseous medium without any influence by the hub unit, in particular the mounting receptacle of the hub unit.

[0036] In particular the sensing section of the sensor head extends beyond the hub unit and is fully exposed to the gaseous medium independent from the hub unit.

[0037] For an optimized communication between the sensor head and the hub unit it is provided that within the mounting section of the sensor housing the at least one first wireless communication unit of the electronic circuit is arranged.

[0038] Further it is of advantage if the at least one second wireless communication unit is arranged in the hub unit close to the mounting receptacle for the respective sensor head in order to obtain an optimized exchange of signals.

[0039] In order to be able to properly fix the mounting section of the sensor head the mounting receptacle of the hub unit is provided with a receiving shape for holding the mounting section of the sensor head in place.

[0040] In particular the receiving shape is designed to enable placing of the sensor housing of the sensor head in the mounting receptacle by only moving the sensor housing of the sensor head with its mounting section in an insertion direction.

[0041] In general, the receiving shape could be designed so that any sensor head with its housing can be received by one and the same mounting receptacle.

[0042] In order to allow only one specific sensor head to be inserted into one specific mounting section the mounting receptacle is provided with a specified receiving shape accepting only one specific type of sensor head the mounting section of which is provided with the shape corresponding to the specified receiving shape.

[0043] This enables safe exchange of the sensor heads for service personal and avoids potential mal-functions.

[0044] Further a preferred solution provides that the receiving shape of the mounting receptacle is defined by the shape of a cross section of said mounting receptacle extending transverse to said insertion direction and the cross section of the mounting section is corresponding thereto.

[0045] In particular the cross section of the receiving shape is defined by a surface structure extending parallel to an insertion direction for said sensor housing of the respective sensor head.

[0046] The surface structure can be realized by various means.

[0047] One solution preferred with respect to its simplicity of design is that the surface structure comprises projections and / or grooves.

[0048] Further a locking system is provided which fixes the sensor housing of the respective sensor head when inserted into the respective mounting receptacle, so that a releasable fixture of the sensor head in the mounting receptacle can be ascertained.

[0049] A preferred solution of the detection device provides that the at least one sensor head with a sensor section of the sensor housing is arranged in a flow path of the gaseous medium for tempering sensitive goods or cargo.

[0050] The advantage of the detection device according to the present invention is that the hub unit is provided with a plurality of sensor heads which in particular are provided with sensing elements sensing different media and there is only one connection, for example a wireless or wired connection, necessary between the hub and the controller. Further the sensor heads due to their wireless connection to the hub can be easily exchanged and designed to protect the electronic circuit and the sensors arranged therein against the environments within said insulating housing, container, or reefer with high humidity and temperature cycles in particular with the presence of marine salt particles.

[0051] The inventive solution does not only refer to a detection device but also to an insulated housing, container or reefer enclosing a storage volume within which temperature sensitive goods or cargo is received and surrounded by gaseous medium wherein according to the present invention a detection device according to one or more of the aforementioned features is arranged in said storage volume.

[0052] In general, the detection device can be placed anywhere within the insulating housing, container or reefer.

[0053] However, a plurality of detection devices can be arranged in the insulating housing, container or reefer.

[0054] A preferred solution however provides that a tempering unit is associated with said storage volume, said tempering unit generating a flow of the gaseous medium circulating through that volume.

[0055] Preferably, said detection device is arranged in said flow of gaseous medium generated by said tempering unit.

[0056] This means that the detection device can be arranged anywhere in said storage volume as long as it is within said flow of gaseous medium.

[0057] One particular preferred solution provides that said detection device is arranged within said tempering unit, preferably in a flow of gaseous medium provided by a blower of said tempering unit, because when leaving said blower the gaseous medium will show an equalized content and equalized parameters.

[0058] In particular, advantageous embodiments of the invention comprise the combination of features as defined by the following consecutively numbered embodiments.

[0059] 1. Detection device for gaseous media, in particular a gaseous medium (18) for tempering sensitive, in particular perishable, goods, said detection device (200) comprising at least one sensor head (210) provided with an electronic circuit (250) comprising at least one sensing element (280) detecting content or parameters of said gaseous medium (18) characterized in that the at least one sensor head (210) is releasably held in position by a sensor hub unit (202), in that the electronic circuit (250) of said at least one sensor head (210) is provided with at least one first wireless communication unit (254) for wireless communication with at least one second wireless communication unit (264) arranged in the hub unit (202) for transmitting electric power from said hub unit (202) to said sensor head (210) and / or transmitting data generated by said electronic circuit (250) from said sensor head (210) to said hub unit (202).

[0060] 2. Detection device according to embodiment 1, wherein the sensor head (210) comprises a sensor housing (220) enclosing the electronic circuit (250) and admitting access of said gaseous medium (18) to said sensing element (280).

[0061] 3. Detection device according to embodiment 2, wherein said sensor housing (220) comprises at least one access opening (290) for said gaseous medium (18).

[0062] 4. Detection device according to embodiment 3, wherein the at least one access opening (290) is covered by a membrane (290). 5. Detection device according to one of the preceding embodiments, wherein the electronic circuit (250) is arranged on a circuit board (248) arranged in an interior space (246) of the sensor housing (220).

[0063] 6. Detection device according to one of the preceding embodiments, wherein a sensing area (284) of said sensing element (280) is covered by a membrane.

[0064] 7. Detection device according to one of the preceding embodiments, wherein said electronic circuit (250) of said at least one sensor head (210) comprises a sensing element (280) detecting humidity.

[0065] 8. Detection device according to one of the preceding embodiments, wherein said electronic circuit (250) of said at least one sensor head (210) comprises a sensing element (280) detecting temperature.

[0066] 9. Detection device according to one of the preceding embodiments, wherein said at least one sensor head (210) comprises a sensing element (280a) detecting CO2.

[0067] 10. Detection device according to one of the preceding embodiments, wherein said at least one sensor head (210) comprises a sensing element (280) detecting oxygen.

[0068] 11. Detection device according to one of the preceding embodiments, wherein said at least one sensing element (280) is arranged on a portion (270) of the circuit board (248) significantly thermally decoupled from the other elements of the electronic circuit (250).

[0069] 12. Detection device according to at least one of embodiments, 7 to 11, wherein said CO2 sensing element, said humidity sensing element (280) and said temperature sensing element are together arranged on a portion (270) of the circuit board (248) significantly thermally decoupled from the other elements of the electronic circuit (250).

[0070] 13. Detection device according to one of the preceding embodiments, wherein said electronic circuit (250) comprises an evaluation circuit (282) which generates sensor data from signals of the respective sensing element (280).

[0071] 14. Detection device according to embodiment 13, wherein said evaluation circuit (282) is detecting the signals of the CO2 sensing element (280a) the humidity sensing element (280b) and the temperature sensing element (280b) and generates CO2 data compensated by the detected humidity and the detected temperature.

[0072] 15. Detection device according to one of the preceding embodiments, wherein the first communication unit (254) and the second communication unit (256) are provided for both, the transfer of energy and the transfer of data.

[0073] 16. Detection device according to one of the preceding embodiments, wherein the communication units (254, 256) are provided for transmitting data in both directions between said hub unit (202) and sensor head (210).

[0074] 17. Detection device according to the preamble of embodiment 1 or to one of the preceding embodiments, wherein said hub unit (202) comprises a mounting receptacle (222) for releasably receiving the at least one sensor head (210).

[0075] 18. Detection device according to embodiment 17, wherein the mounting receptacle (222) receives a mounting section (218) of the sensor housing (220) of the respective sensor head (210).

[0076] 19. Detection device according to embodiment 17 or 18, wherein the mounting section (218) of the sensor housing (220) of the sensor head (210) received by the mounting receptacle (222) is arranged opposite to the sensor section (216) of the sensor housing (220) receiving the sensing element (280).

[0077] 20. Detection device according to one of embodiments 17 to 19, wherein within the mounting section (218) of the sensor housing (220) the at least one first wireless communication unit (254) of the electronic circuit (250) is arranged.

[0078] 21. Detection device according to one of embodiment 17 to 20, wherein the at least second wireless communication (264) unit is arranged in the hub unit (202) close to the mounting receptacle (222) for the respective sensor head (210).

[0079] 22. Detection device according to one of embodiments 17 to 21, wherein the mounting receptacle (222) of the hub unit (202) is provided with a receiving shape (230) for holding the mounting section (218) of the sensor head (210) in place.

[0080] 23. Detection device according to embodiment 22, wherein the receiving shape enables placing of the sensor housing (220) of the sensor head (210) in the mounting receptacle (222) by only moving the sensor housing (220) of the sensor head (210) with its mounting section (218) in an insertion direction (228).

[0081] 24. Detection device according to one of embodiments 22 or 23, wherein a mounting section (218) of the sensor housing (220) comprises an outer shape adapted for insertion into the receiving shape.

[0082] 25. Detection device according to one of embodiments 22 to 24, wherein the mounting receptacle (222) is provided with a specified receiving shape (240) accepting only one specific type of sensor head (210) the mounting section (218) of which is provided with an outer shape (230) corresponding to the specified receiving shape (240). 26. Detection device according to one of embodiments 22 to 25, wherein the receiving shape of the mounting receptacle (222) is defined by the shape of a cross section (240) of said mounting receptacle (222) extending transverse to said insertion direction (228) and a cross section (230) of the shape of the mounting section (218) is corresponding thereto.

[0083] 27. Detection device according to embodiments 25 or 26, wherein the cross section (240) of the receiving shape (240) is defined by a surface structure (224, 242) extending parallel to an insertion direction (228) for said sensor housing (220) of the respective sensor head (210).

[0084] 28. Detection device according to embodiment 27, wherein the surface structure comprises projections and / or grooves (224, 226242, 244).

[0085] 29. Detection device according to one of the embodiments 17 to 28, wherein a locking system fixes the sensor housing (220) of the respective sensor head (210) when inserted in the respective mounting receptacle (222).

[0086] 30. Detection device according to one of the preceding embodiments, wherein the at least one sensor head (210) with the sensor section (216) of the sensor housing (220) is arranged in a flow path of gaseous medium for tempering sensitive goods or cargo (16).

[0087] 31. Insulated housing, container or reefer (12), enclosing a storage volume (14) within which temperature sensitive goods or cargo (16) is received and surrounded by gaseous medium (18) characterized in that a detection device (200) according to one of embodiments 1 to 30 is arranged in said storage volume (14).

[0088] 32. Insulated housing, container or reefer (12), according to embodiment 31, wherein a tempering unit (24) is associated with said storage volume (14), said tempering unit (24) generating a flow (22) of the gaseous medium (18) circulating through said volume (14).

[0089] 33. Insulated housing according to embodiment 32, wherein said detection device (200) is arranged in said flow (22) of gaseous medium (18) generated by said tempering unit (24).

[0090] 34. Insulated housing according to embodiment 31 or 32, wherein said detection device (200) is arranged within said tempering unit (24).

[0091] 35. Sensor head for use in a detection device (200), in particular according to at least one of embodiments 1 to 31, said sensor head (210) comprising an electronic circuit (280) detecting content parameters of a gaseous medium, and at least one first wireless communication unit (254) for communication with at least one second wireless communication unit (264) arranged in a hub unit (202) for transmitting electric power from said hub unit (202) to said sensor head (210) and / or transmitting data generated by said electronic circuit (250) from said sensor head (210) to said hub unit (202).

[0092] Further features and advantages of the present invention are disclosed in the following detailed specification.

[0093] In the figures:

[0094] Fig. 1 shows a longitudinal sectional view through a storage unit according to the present invention provided with a refrigerant circuit for cooling;

[0095] Fig. 2 a side view of one example of an inventive storage unit;

[0096] Fig. 3 a front view of the example according to Fig. 2 ofthe inventive storage unit; Fig. 4 a front view according to fig. 3 of the inventive storage unit provided with the refrigerant circuit and a control with a front cover removed;

[0097] Fig. 5 a perspective view of a detection unit with a hub unit and the sensor head mounted;

[0098] Fig. 6 the perspective view according to Fig. 5 with the sensor head on the left-hand side in a position before insertion into the hub unit and the sensor head in the middle in an unlocked position;

[0099] Fig. 7 a view in direction A in Fig. 5 on the hub unit with all sensor heads removed;

[0100] Fig. 8 a sectional view along 8-8 in Fig. 5;

[0101] Fig. 9 a longitudinal sectional view along lines 9-9 in Fig. 5;

[0102] Fig. 10 a top view on a circuit board arranged in the sensor head with a first version of the electronic circuit;

[0103] Fig. 11 a top view according to Fig. 10 shown a second version of the electronic circuit;

[0104] Fig. 12 a view on the hub unit in direction B in Fig. 5 with the sensor heads mounted but showing the interior of the sensor heads with part of an electronic circuit on a circuit board.

[0105] The invention is explained for example in connection with a storage unit 10 comprising an insulated housing 12 enclosing a storage volume 14 within which temperature sensitive in particular perishable goods or cargo 16 is received and surrounded by a gaseous medium 18, in particular air, which is kept at a defined temperature level for maintaining said goods or cargo 16 in a defined temperature range (Fig. 1).

[0106] However, the inventive concept can be used in connection with any other environment, for example a stationary insulated storage room.

[0107] Said storage unit 10 can be for example a storage unit 10 in a supermarket or any other warehouse.

[0108] Said storage unit 10 can also be a transportable storage unit 10, for example of a truck or a trailer (Fig. 2, 3) or a ship or a railway carriage transporting goods or cargo 16 or a conventional container or reefer for example a reefer for shipping goods or cargo 16 by truck, railway or ship.

[0109] In order to maintain a defined or set temperature range of cargo 16 a flow 22 of said gaseous medium 18 is circulating through volume 14 by starting from a tempering unit 24 as a supply gas flow 26 and entering tempering unit 24 as a return gas flow 28.

[0110] The circulating flow 22 of gaseous medium is for example generated by a blower arrangement 32 preferably arranged within tempering unit 24 and tempered by a heat exchange unit 34 arranged within tempering unit 24 (Fig. 1).

[0111] Preferably supply gas flow 26 exits from tempering unit 24 in an area close to a lower wall 38 of insulated housing 12 and preferably returns to tempering unit 24 close to an upper wall 36 of insulated housing 12 forming said return gas flow 28.

[0112] According to a preferred embodiment heat exchange unit 34 comprises a heat absorbing heat exchanger 42 arranged in a refrigerant circuit 40 as shown in Fig. 4 and in particular further comprises heaters 46 (Fig. 1) which are for example electric heaters, used for example for defrosting heat absorbing heat exchangers 42.

[0113] Tempering unit 24 is for example arranged between lower wall 38 and upper wall 36 of isolated housing 12, in particular on a front wall 48 or a rear wall thereof.

[0114] However, tempering unit 24 can also be arranged on upper wall 36 or lower wall 38.

[0115] Tempering unit 24 is associated with peripheric unit 52 arranged on an outer side of housing 12 which comprises a heat releasing heat exchanger 62 and a blower arrangement 64 for generating a flow of ambient air 66 through heat releasing heat exchanger 62.

[0116] In case of a transportable storage unit 10 peripheric unit 52 further comprises a compressor arrangement 54 and a power source 58 represented by a battery provided and for example integrated in peripheric unit 52, which is supplying electric power over a certain period of time for operating refrigerant circuit independent of a mains power supply network and which is rechargeable by any power supply from time to time.

[0117] In an alternative embodiment the compressor arrangement 54 can be driven by a prime mover directly or via a generator.

[0118] In case of a stationary unit 10 compressor arrangement 54 can be powered by a mains power supply network for example by use of a battery charger for the battery 58.

[0119] Refrigerant circuit 40, as shown in Fig. 4 and 5, comprises a low pressure section 72, in which heat absorbing heat exchanger 42 is arranged and a high pressure section 74, in which a heat releasing heat exchanger 62 is arranged, and the compressor arrangement 54 connected with a suction connection 82 to low pressure section 72 of refrigerant circuit 40, in particular to an outlet 84 of heat absorbing heat exchanger 42, and with a discharge connection 86 is connected to high pressure section 74 of refrigerant circuit 40 which is connected an inlet 88 of heat releasing heat exchanger 62, so that compressor arrangement 54 generates and thereby compresses a flow of refrigerant from low pressure section 72 to high pressure section 74.

[0120] Further cooling circuit 40 comprises an expansion device 94 being connected directly or indirectly to an outlet 104 of heat releasing heat exchanger 62, for example via an expansion device 102 and a flash gas tank 90 for liquid refrigerant, and expansion device 94 is connected with its outlet 106 to an inlet 108 of heat absorbing heat exchanger 42.

[0121] Gaseous refrigerant collected above a bath of liquid refrigerant in receiver 90 is expanded via expansion device 92 to an intermediate pressure and guided to intermediate pressure connection 96 of two stage compressor arrangement 54. Electric drive 132, for example an electric motor, of compressor arrangement 54 is cooled by refrigerant from heat absorbing heat exchanger 42 before being compressed to high pressure at discharge connection 86.

[0122] However, as an alternative electric drive 132 can also be cooled by refrigerant supplied via intermediate pressure connection 96 or compressed refrigerant at high pressure before heaving through discharge connection 86.

[0123] A controller 120 associated with cooling circuit 40 is for example connected to a pressure sensor 122 associated with low pressure section 72 and / or a temperature sensor 124 associated with low pressure section 72 and also connected to a pressure sensor 126 associated with high pressure section 74 and / or a temperature sensor 128 associated with high pressure section 74.

[0124] Further controller 120 is for example connected to a variable frequency converter 130 powering variable frequency electric drive 132, being for example a motor, representing a first actuator for driving compressor arrangement 54 and to a drive 134 for adjusting expansion device 94.

[0125] Drive 134 is an electric drive representing another possible actuator for adjusting expansion device 94 which is for example an expansion valve.

[0126] Further adjusting drive 136 is representing another possible actuator for adjusting expansion device 92.

[0127] Said cooling circuit 40 is in particular operated by said controller 120 in a heat transfer mode in which compressor arrangement 54 is driven speed controlled by means of variable frequency converter 130 for powering electric drive 132 and said expansion device 94 is controlled in accordance with the amount of heat to be transferred from said heat absorbing heat exchanger 42 extracting heat from said return gas flow 28 in order to obtain a cooled supply gas flow 26 blown into storage volume 14 to heat releasing heat exchanger 62 releasing heat into the flow of ambient air 66 depending on the temperature of the flow of ambient air 66.

[0128] In order to maintain a defined circulating flow of ambient air, heat releasing heat exchanger 62 is associated with a blower arrangement 152 driven for example by an electric motor, which is controlled by controller 120.

[0129] The operation of heat releasing heat exchanger 62 is monitored by a temperature sensor 156 detecting the temperature of ambient air and for example in addition a temperature sensor 158 detecting the temperature of exiting air.

[0130] In order to maintain a defined flow 22 of gaseous medium 18 heat exchanger unit 34 is associated with blower arrangement 32 driven by an electric drive, for example by a frequency controlled electric drive 144, in particular an electric motor, representing a third actuator which is controlled by controller 120.

[0131] In addition, an improved monitoring of the operation of heat exchanger unit 34, in particular heat absorbing exchanger 42, is possible by controller 120 if temperature sensor 146 is provided detecting the temperature of return gas flow 28 and temperature sensor 148 is provided detecting the temperature of supply gas flow 26.

[0132] In order to obtain information of the temperature of the cargo 16 itself a cargo space sensor 172 (Fig. 1, 5) within storage volume 14 is provided, for example in maximum distance from tempering unit 24 and / or at least one cargo temperature sensor 174 is attached to the cargo 16 itself, in communication, in particular wireless communication, with controller 120.

[0133] Controller 120 in particular comprises a processor 176 associated with a memory 178 (Fig. 4).

[0134] Controller 120 is provided with a user panel 180 enabling operational control and for example access the data in particular also input of the data stored in memory 178.

[0135] In order to analyze the gaseous medium 18 circulating through volume 14 a detection device 200, connected to the controller 120, is provided which for analyzing said gaseous medium 18 is preferably arranged in said flow 22, in particular arranged within tempering unit 24 and within tempering unit 24 between blower arrangement 32 and heat exchange unit 34 in order to enable detection of the components and parameters of said gaseous medium, in particular detection of the composition of the gaseous medium and physical parameters, in the flow 22 of gaseous medium coming from the blower 32 and therefore being mixed accelerated and equalized therein for optimized analysis by detection device 200. As shown for example in Fig. 5 the detection device 200 comprises a hub unit 202 is provided with a mounting portion 204 on which one or more sensor heads 210a, 210b and 210c can be mounted.

[0136] Each sensor head 210 is provided with a sensor housing 220 having a sensor section 216 and a mounting section 218.

[0137] The mounting portion 204 is provided with foot elements 206a, 206b which enable arrangement of said mounting portion 204 at a certain distance from a wall 208 of tempering unit 24 in order to expose sensor heads 210a, 210b and 210c to allow an optimized exposure of sensor heads 210 in particular with their sensor sections 216 to gaseous medium 18, in particular the flow 22 of gaseous medium 18 between wall 208 and a side 212 of mounting portion 204 directed towards wall 208 as well as the flow 22 of gaseous medium along side 214 of mounting portion 204 opposite to side 212 and directed away from wall 208.

[0138] As for example shown in Fig. 6 mounting portion 204 of hub unit 202 comprises a mounting receptacle 222 for each sensor head 210 which can be releasably mounted with the mounting section 218 of the sensor housing 220 in its corresponding mounting receptacle 222.

[0139] In particular each mounting receptacle 222 comprises guide elements 224 which cooperate with corresponding guide elements 226 arranged on the mounting section 218 of the sensor housing 220 of the respective sensor head 210 in order to enable insertion of the respective sensor head 210 with its mounting section 218 into the respective mounting receptacle 222 by movement along an insertion / removal direction 228.

[0140] Guide elements 224 and the corresponding guide elements 226 can be for example groves and bars corresponding to said groves. As for example shown in Fig. 6 and 7 each mounting receptacle 222 is provided with a mechanical identifier element 242 which cooperates with the corresponding mechanical identifier element 244 arranged in the corresponding sensor head 210 in order to unequivocally associate with each mounting receptacle 222 only use of the corresponding sensor head 210 and avoid insertion of a non-corresponding sensor head 210 into one of the mounting receptacles 222 due to misfit between the mechanical identifier elements 242 and 244 for example such mechanical identifier element 242 and the corresponding mechanical identifier element 244 can be protrusions and / or ribs extending parallel to insertion / removal direction 228 which will consequently prevent insertion of an non-allowed sensor head 210 with the respective mounting receptacle 222 when moved in insertion / removal direction 228.

[0141] The combination of guide elements 224 and 226 as well as mechanical identifier elements 242 and 244 provides on one hand a guiding function for guiding in insertion / removal direction 228 and in addition a mechanical identifier function enabling only insertion of an allowed sensor head 210 into the corresponding mounting receptacle 222.

[0142] The mechanical identifier function enables to associate different sensor heads 210 each provided for detection of a specified medium with a specified mounting receptacle 222.

[0143] This combination of guide elements 226 and identifier elements 244 defines a cross section 230 of the mounting section 218, transverse to insertion / removal direction 228 and the combination of guide elements 224 and identifier elements 242 of the mounting receptacle 222 defines a cross section 240 of the mounting receptacle 222, in particular its cross section transverse to insertion / removal direction 228 in order to enable proper guidance and proper mechanical identification of the respective mounting section 218 with respect to the corresponding mounting receptacle 222 in order to achieve the purpose of proper guidance in insertion / removal direction 228 as well as proper mechanical identification of the respective mounting section 228 and the mounting receptacle 222.

[0144] In order to fix the inserted sensor heads 210 within said mounting receptacles 222 the sensor heads 210 are provided with locking elements 232 which cooperate with locking elements 234 arranged on said mounting receptacle 222 which can be realized for example by an elastic locking finger which can snap into a locking recess for fixing said respective sensor head 210 within said mounting receptacle 222.

[0145] For removal of said respective sensor head 210 the movable lock element, for example locking element 232, can be manually actuated in order to release the form locking between form locking element 232 and 234 and to remove sensor head 210 from the respective mounting receptacle 222.

[0146] Therefore, locking elements 232 enable a tool-free mounting or unmounting by enabling proper fixation of the locking element 232 in hub unit 202.

[0147] As shown for example in Fig. 9 in an interior space 246 within each housing 220 of the respective sensor head 210 there is arranged a circuit board 248 extending within sensor section 216 and mounting section 218 being provided with an electronic circuit 250. Within mounting section 218 electronic circuit 250 is provided with an antenna element 252 which is part of a first wireless communication unit 254 with a at least one communication circuit 256 comprised by electronic circuit 250 and connected to antenna element 252.

[0148] The first wireless communication unit 254 is communicating with a second wireless communication unit 264 which is part of an electronic circuit 260 arranged within mounting portion 204 of hub unit 202 on a circuit board 268 which electronic circuit 260 comprises a second antenna element 262 of the second wireless communication unit 264 which antenna element 262 is arranged adjacent to mounting portion 204 so that it will be arranged opposite and close to antenna element 252 in case the respective sensor head 210 is inserted into mounting receptacle 222 with mounting sections 218 of sensor housing 220.

[0149] The second antenna element 262 is connected to communication circuit 266 also arranged on circuit board 268 and coupled to second antenna element 262.

[0150] Further circuit board 248 is provided with a sensor carrier area 270 arranged at maximum distance from first wireless communication unit 254 and being part of electronic circuit 250 but separate from other areas of circuit board 248 by cutouts 272 enabling decoupling of at least one sensing element 280 from a remaining portion 274 of the circuit board 248 carrying electronic circuit 250 with the first wireless communication unit 254 with antenna element 252 and communication circuit 256 as well as carrying an evaluation circuit 282 for evaluating the signals of at least one sensing elements 280.

[0151] The cutouts 272 enable separation of the at least one sensing element 280 with respect to remaining portion 274 of circuit board 250 with respect to any thermal influence which could have negative impact on the signals generated by the at least one sensing element 280.

[0152] Further the sensor section 216 of housing 220 in the area facing the at least one sensing element 280 is provided with access openings 290 enabling access of gaseous medium 18 to the interior space 246 of sensor housing 220.

[0153] In order to avoid any unwanted particles or condensed media to enter interior space 248 access openings 290 of sensor housing 220 are covered by membrane 292 allowing only entry of gas without any undesired particles or condensed media into interior space 248 of housing 220.

[0154] For example, membrane 292 is made of PTFE. The sensing element 280 can be a sensing element for temperature and / or humidity.

[0155] The sensing element 280 can be a sensing element for oxygen.

[0156] In the special case where the sensing element 280a is a sensing element for CO2 gas being a component of the gaseous medium 18 there is provided on the same sensor area 270 another sensor 280b which is able to detect relative humidity as well as temperature.

[0157] This arrangement is due to the fact that the sensing of CO2 gas is rather sensitive to other parameters of the gaseous medium 18 and can be in particular influenced by the relative humidity and the temperature and for this reason the same sensor area 270 which carries sensing element 280a is also carrying sensing element 280b just aside of sensing element 280a in order to enable direct detection of relative humidity and the temperature and enabling evaluation circuit 282 to compensate in time without any time delay for the direct influence of relative humidity and temperature on the detected signal related to the CO2 gas content.

[0158] In addition to membrane 292 covering access openings 290 of housing 220 sensing element 280b itself is also provided with a membrane 294 covering a sensing area 284 thereof and only allowing access of gaseous medium 18 to the sensing area 284.

[0159] For all kinds of sensing elements 280 the signals generated therein are evaluated in evaluation circuit 282 associated therewith and sensor data indicating the respective parameter or content of the gaseous medium 18 are generated.

[0160] These data generated by evaluation circuit 282 are transferred to communication circuit 256 for communicating these data via first wireless communication unit 254 to second wireless communication unit 264 the communication circuit 266 of which is transferring these data to transmitter 300 for being transmitted to controller 120 in order to be stored therein for any control process or for use on panel 180 for being displayed.

[0161] In addition, data for instance concerning the measurement of data or updates for the evaluation circuit 282 can be transferred from the second wireless communication unit 264 to the first wireless communication unit 254.

[0162] In addition, circuit board 268 is provided with a power supply unit 302 providing second wireless communication unit 264 with electric power for operating second wireless communication unit 264 and for in addition transferring electric energy to first wireless communication unit 254 for operating evaluation circuit 282 and sensing elements 280.

[0163] In order to fully protect first wireless communication unit 254 as well as evaluation circuit 282 against any influence of the gaseous medium entering interior space 248 of sensor housing 220 the circuit board 248 together with electronic circuit 250 comprising at least the components of first wireless communication unit 254, in particular antenna element 252 and communication circuit 256 as well as evaluation circuit 282, are covered by a protection layer 310 so that gaseous medium 18 entering interior space 248 cannot affect operation of the electronic circuit 250, so that the only electronic component being in contact with the gaseous medium 18 within interior space 246 is the respective sensing element 280.

[0164] A preferred version of the detection unit 200 comprises, as shown in Fig. 5 to 8 and 12, three sensor heads 210a, 210b, 210c, whereas for example sensor head 210a with its sensing element 280a detects CO2 and with its sensing element 280b in addition temperature and humidity, sensor head 210b with its sensing element 280 detects oxygen, and sensor head 210c with its sensing element 280 detects temperature and humidity. Due to the different gas content and parameters detected by the respective sensor head 210a, 210b, 210c each mounting receptacle 222a, 222b and 222c due to its respective cross section 240 and the corresponding cross section 230 of the mounting sections 218 only allow insertion of the sensor head 210a into mounting receptacle 222a, sensor head 210b only into a mounting receptacle 222b and sensor head 210c only into mounting receptacle 222c.

[0165] Consequently, in case one of the sensor heads 210a, 210b or 210c is defect any misplacement of one of the other sensor heads 210a, 210b or 210c in the mounting receptacle 222a or 222b or 222c of the defect sensor 210 is avoided.

Claims

CLAIMS1. Detection device for gaseous media, in particular a gaseous medium (18) for tempering sensitive, in particular perishable, goods, said detection device (200) comprising at least one sensor head (210) provided with an electronic circuit (250) comprising at least one sensing element (280) detecting content or parameters of said gaseous medium (18) characterized in that the at least one sensor head (210) is releasably held in position by a sensor hub unit (202), in that the electronic circuit (250) of said at least one sensor head (210) is provided with at least one first wireless communication unit (254) for wireless communication with at least one second wireless communication unit (264) arranged in the hub unit (202) for transmitting electric power from said hub unit (202) to said sensor head (210) and / or transmitting data generated by said electronic circuit (250) from said sensor head (210) to said hub unit (202).

2. Detection device according to claim 1 wherein the sensor head (210) comprises a sensor housing (220) enclosing the electronic circuit (250) and admitting access of said gaseous medium (18) to said sensing element (280).

3. Detection device according to claim 2 wherein said sensor housing (220) comprises at least one access opening (290) for said gaseous medium (18).

4. Detection device according to claim 3, wherein the at least one access opening (290) is covered by a membrane (290).

5. Detection device according to one of the preceding claims wherein the electronic circuit (250) is arranged on a circuit board (248) arranged in an interior space (246) of the sensor housing (220).

6. Detection device according to one of the preceding claims wherein a sensing area (284) of said sensing element (280) is covered by a membrane.

7. Detection device according to one of the preceding claims, wherein said electronic circuit (250) of said at least one sensor head (210) comprises a sensing element (280) detecting humidity.

8. Detection device according to one of the preceding claims, wherein said electronic circuit (250) of said at least one sensor head (210) comprises a sensing element (280) detecting temperature.

9. Detection device according to one of the preceding claims, wherein said at least one sensor head (210) comprises a sensing element (280a) detecting CO2.

10. Detection device according to one of the preceding claims, wherein said at least one sensor head (210) comprises a sensing element (280) detecting oxygen.

11. Detection device according to one of the preceding claims, wherein said at least one sensing element (280) is arranged on a portion (270) of the circuit board (248) significantly thermally decoupled from the other elements of the electronic circuit (250).

12. Detection device according to at least one of claims, 7 to 11, wherein said CO2 sensing element, said humidity sensing element (280) and said temperature sensing element are together arranged on a portion (270) of the circuit board (248) significantly thermally decoupled from the other elements of the electronic circuit (250).

13. Detection device according to one of the preceding claims, wherein said electronic circuit (250) comprises an evaluation circuit (282) which generates sensor data from signals of the respective sensing element (280).

14. Detection device according to claim 13, wherein said evaluation circuit (282) is detecting the signals of the CO2 sensing element (280a) the humidity sensing element (280b) and the temperature sensing element (280b) and generates CO2 data compensated by the detected humidity and the detected temperature.

15. Detection device according to one of the preceding claims, wherein the first communication unit (254) and the second communication unit (256) are provided for both, the transfer of energy and the transfer of data.

16. Detection device according to one of the preceding claims, wherein the communication units (254, 256) are provided for transmitting data in both directions between said hub unit (202) and sensor head (210).

17. Detection device according to the preamble of claim 1 or to one of the preceding claims, wherein said hub unit (202) comprises a mounting receptacle (222) for releasably receiving the at least one sensor head (210).

18. Detection device according to claim 17, wherein the mounting receptacle (222) receives a mounting section (218) of the sensor housing (220) of the respective sensor head (210).

19. Detection device according to claim 17 or 18, wherein the mounting section (218) of the sensor housing (220) of the sensor head (210) received by the mounting receptacle (222) is arranged opposite to thesensor section (216) of the sensor housing (220) receiving the sensing element (280).

20. Detection device according to one of claim 17 to 19, wherein within the mounting section (218) of the sensor housing (220) the at least one first wireless communication unit (254) of the electronic circuit (250) is arranged.

21. Detection device according to one of claim 17 to 20, wherein the at least second wireless communication (264) unit is arranged in the hub unit (202) close to the mounting receptacle (222) for the respective sensor head (210).

22. Detection device according to one of claims 17 to 21, wherein the mounting receptacle (222) of the hub unit (202) is provided with a receiving shape (230) for holding the mounting section (218) of the sensor head (210) in place.

23. Detection device according to claim 22, wherein the receiving shape enables placing of the sensor housing (220) of the sensor head (210) in the mounting receptacle (222) by only moving the sensor housing (220) of the sensor head (210) with its mounting section (218) in an insertion direction (228).

24. Detection device according to one of claims 22 or 23, wherein a mounting section (218) of the sensor housing (220) comprises an outer shape adapted for insertion into the receiving shape.

25. Detection device according to one of claims 22 to 24, wherein the mounting receptacle (222) is provided with a specified receiving shape (240) accepting only one specific type of sensor head (210) the mounting section (218) of which is provided with an outer shape (230) corresponding to the specified receiving shape (240).

26. Detection device according to one of claims 22 to 25, wherein the receiving shape of the mounting receptacle (222) is defined by the shape of a cross section (240) of said mounting receptacle (222) extending transverse to said insertion direction (228) and a cross section (230) of the shape of the mounting section (218) is corresponding thereto.

27. Detection device according to claims 25 or 26, wherein the cross section (240) of the receiving shape (240) is defined by a surface structure (224, 242) extending parallel to an insertion direction (228) for said sensor housing (220) of the respective sensor head (210).

28. Detection device according to claim 27, wherein the surface structure comprises projections and / or grooves (224, 226242, 244).

29. Detection device according to one of the claims 17 to 28, wherein a locking system fixes the sensor housing (220) of the respective sensor head (210) when inserted in the respective mounting receptacle (222).

30. Detection device according to one of the preceding claims, wherein the at least one sensor head (210) with the sensor section (216) of the sensor housing (220) is arranged in a flow path of gaseous medium for tempering sensitive goods or cargo (16).

31. Insulated housing, container or reefer (12), enclosing a storage volume (14) within which temperature sensitive goods or cargo (16) is received and surrounded by gaseous medium (18) characterized in that a detection device (200) according to one of claims 1 to 30 is arranged in said storage volume (14).

32. Insulated housing, container or reefer (12), according to claim 31, wherein a tempering unit (24) is associated with said storage volume(14), said tempering unit (24) generating a flow (22) of the gaseous medium (18) circulating through said volume (14).

33. Insulated housing according to claim 32, wherein said detection device (200) is arranged in said flow (22) of gaseous medium (18) generated by said tempering unit (24).

34. Insulated housing according to claim 31 or 32, wherein said detection device (200) is arranged within said tempering unit (24).

35. Sensor head for use in a detection device (200), in particular according to at least one of claims 1 to 31, said sensor head (210) comprising an electronic circuit (280) detecting content parameters of a gaseous medium, and at least one first wireless communication unit (254) for communication with at least one second wireless communication unit (264) arranged in a hub unit (202) for transmitting electric power from said hub unit (202) to said sensor head (210) and / or transmitting data generated by said electronic circuit (250) from said sensor head (210) to said hub unit (202).

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