Liquid exposure sensing device and controller

Abstract

One example discloses a liquid exposure sensing device, comprising: a first sensor configured to be coupled to a reference material; wherein the first sensor is configured to generate a first signal in response to a liquid phase and / or a vapor phase of a substance passing through the reference material; a second sensor configured to be coupled to an exposed material; wherein the second sensor is configured to generate a second signal in response to the liquid phase and / or the vapor phase of the substance passing through the exposed material; and a controller coupled to the first and second sensors and configured to generate a liquid detection signal in response to a time delay between the first signal and the second signal exceeding a threshold time delay.

Description

Technical Field

[0001] The present specification relates to systems, methods, devices, apparatus, articles of manufacture, and instructions for detecting liquid exposure. Background Art

[0002] Moisture detection in cardboard packaging materials and detection of wetting by liquid water; and the ability to detect high humidity conditions are important parameters (second only to temperature) for monitoring logistics operations; however, current moisture meters and relative humidity measurement systems focus on measuring moisture, not finding the cause of moisture changes.

[0003] In many logistics, warehousing and delivery applications, changes in package moisture due to relative humidity are allowed, but changes due to wetting are not allowed. It should be noted that direct contact with water, for example, is different from 100% humidity and condensation, which can occur without direct wetting. For example, moving a package from a cold storage to a hot, high humidity environment will result in condensation but not in direct wetting as defined herein. However, splashing liquids, rain, spills, etc. are forms of direct wetting.

[0004] Whether a package has experienced high humidity or wetting can be very important in the shipping and storage of various pharmaceuticals, parcel mail items, and other important packaging. Customers often pay extra money to verify that the customer's package has not been wet during transportation, or to identify if the package has indeed been wet. This type of information can have an impact on package integrity, quality control, and insurance claims. Summary of the invention

[0005] According to an example embodiment, a liquid exposure sensing device includes: a first sensor configured to be coupled to a reference material; wherein the first sensor is configured to generate a first signal in response to a liquid phase and / or a vapor phase of a substance passing through the reference material; a second sensor configured to be coupled to an exposed material; wherein the second sensor is configured to generate a second signal in response to a liquid phase and / or a vapor phase of a substance passing through the exposed material; and a controller coupled to the first sensor and the second sensor and configured to generate a liquid detection signal in response to a time delay between the first signal and the second signal that exceeds a threshold time delay.

[0006] In another example embodiment, the first sensor and the second sensor are impedance sensors and the first signal and the second signal are impedance signals.

[0007] In another example embodiment, the first sensor and the second sensor are capacitive sensors and the first signal and the second signal are capacitive signals.

[0008] In another example embodiment, the amplitude of the capacitance signal increases in response to the vapor phase of the substance increasing.

[0009] In another example embodiment, the first sensor and the second sensor are conductive sensors and the first signal and the second signal are conductive signals.

[0010] In another example embodiment, the amplitude of the conductive signal increases in response to the liquid phase of the substance increasing.

[0011] In another example embodiment, the first sensor is configured to be in galvanic contact with the reference material and the second sensor is configured to be in galvanic contact with the exposed material.

[0012] In another example embodiment, the exposed material and the reference material are the same type of material.

[0013] In another example embodiment, the exposed material and the reference material are different types of materials.

[0014] In another example embodiment, the exposed material and the reference material have the same material thickness.

[0015] In another example embodiment, the exposed material and the reference material have different material thicknesses.

[0016] In another example embodiment, the exposure material is configured to be in direct contact with the liquid phase of the substance before the reference material is in direct contact with the liquid phase of the substance.

[0017] In another example embodiment, the first sensor and the second sensor are configured to measure both capacitance and conductance; and the controller is configured to generate a liquid detection signal in response to the first signal and the second signal exceeding a threshold capacitance time delay and the third signal and the fourth signal from the first sensor and the second sensor exceeding a threshold conductance time delay.

[0018] In another example embodiment, the controller is configured to generate the liquid condensation signal in response to the first signal or the second signal exceeding an amplitude threshold signal level.

[0019] In another example embodiment, the controller includes a memory element that records when and / or whether the liquid and / or vapor phase of the substance passes through the exposure material and / or the reference material during one or more legs of the physical transport trip.

[0020] In another example embodiment, further included is a coating that separates the first sensor and the reference material from the surrounding environment; wherein the coating is permeable to the vapor phase but impermeable to the liquid phase.

[0021] In another example embodiment, both the first sensor and the second sensor are responsive to the vapor phase of the substance.

[0022] In another example embodiment, the exposed material and / or the reference material is at least one of: paper, cardboard, cloth, mesh, or fabric.

[0023] In another example embodiment, further included is a package having a cavity; wherein an interior surface of the cavity is lined with the exposed material; and wherein the reference material is outside of the cavity.

[0024] In another example embodiment, further included is a package having a cavity; wherein an outer surface of the cavity is lined with the exposed material; and wherein the reference material is inside the cavity.

[0025] In another example embodiment, a substrate is further included; wherein the first sensor is on one side of the substrate and the second sensor is on an opposite side of the substrate.

[0026] According to an example embodiment, a liquid exposure controller circuit includes: a controller circuit configured to be coupled to a first sensor and a second sensor; wherein the first sensor is configured to be coupled to a reference material and is configured to generate a first signal in response to a liquid phase and / or a vapor phase of a substance passing through the reference material; wherein the second sensor is configured to be coupled to an exposed material and is configured to generate a second signal in response to a liquid phase and / or a vapor phase of a substance passing through the exposed material; and wherein the controller circuit is configured to generate a liquid detection signal in response to a reception time delay between the first signal and the second signal that exceeds a threshold time delay.

[0027] The above discussion is not intended to present every example embodiment or every implementation that is within the scope of the current or future claim sets.The figures and the following detailed description also illustrate various example embodiments.

[0028] Various example embodiments may be more fully understood by considering the following detailed description in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 is an example of a liquid exposure sensing device.

[0030] Figure 2 is an example of a portion of the liquid exposed sensing device before folding.

[0031] Figure 3 is an example of a liquid exposed sensing device after coating.

[0032] Figure 4A and Figure 4B A first set of examples of a first signal from a first sensor and a second signal from a second sensor.

[0033] Figure 5A and Figure 5BA second set of examples of a first signal from a first sensor and a second signal from a second sensor.

[0034] Fig. 6A and Figure 6B A third set of examples of a first signal from a first sensor and a second signal from a second sensor.

[0035] Fig. 7A and Figure 7B A fourth set of examples of a first signal from a first sensor and a second signal from a second sensor.

[0036] Fig. 8A and Figure 8B A fifth set of examples of a first signal from a first sensor and a second signal from a second sensor.

[0037] Although the present disclosure allows various modifications and alternative forms, the details of the present disclosure have been shown in the drawings by way of example and will be described in detail. However, it should be understood that in addition to the specific embodiments described, other embodiments are also possible. All modifications, equivalents and alternative embodiments that fall within the spirit and scope of the appended claims are also covered. DETAILED DESCRIPTION

[0038] Discussed herein are example embodiments of a liquid exposure sensing apparatus which, if applied to a package, medical device, or other object to be monitored, would distinguish between whether the package, medical device, or other object to be monitored has been exposed to and / or dropped in water or another liquid, or whether the package has merely experienced a high humidity ambient environment resulting in possible condensation during one or more legs of the package's transport journey.

[0039] In some example embodiments, the liquid exposure sensing device includes two materials (i.e., an exposure material, a material under test, etc., and a reference material) wherein the two materials are separated such that the two materials do not experience any wetting at the same time, and / or the moisture content of both is allowed to change due to changes in relative humidity rather than due to wetting (e.g., protecting the "reference material from getting wet"). This type of protection from getting wet is different from normal encapsulation that not only protects the reference material from getting wet, but also from exposure to relative humidity.

[0040] Figure 1 1 is an example of a liquid exposure sensing device 100. The liquid exposure sensing device 100 includes a substrate support 102, a sensor substrate 104, a first sensor 106 coupled to a reference material 116, a second sensor 110 coupled to the exposed material 114, a first ground plate 108 for shielding the first sensor 106 from the exposed material 114, and a second ground plate 112 for shielding the second sensor 110 from the reference material 116.

[0041] An exposed material 114 (eg, a material under test) is exposed to an ambient environment to be monitored. As such, the ambient environment may be a vapor phase 120 or a liquid phase 122 of a substance 118. In one example embodiment, the exposed material 114 is an outwardly facing surface of a package.

[0042] It should be noted that in some examples, vapor phase 120 of substance 118 is governed by pore forces in materials 114 , 116 , and liquid phase 122 of substance 118 is governed by capillary forces in materials 114 , 116 .

[0043] The reference material 116 is semi-protected from the surrounding environment to be monitored (e.g., can be exposed to the vapor phase 120 of the substance 118 but not to the liquid phase 122 of the substance 118). In one example embodiment, the reference material 116 is somewhere inside the package. For example, if the package has a cavity, the outer surface of the cavity can be lined with the exposed material 114, and the reference material 116 is on the inside of the cavity. Alternatively, the inner surface of the cavity can be lined with the exposed material 114, and the reference material 116 is on the outside of the cavity.

[0044] In various embodiments, the package and any of the materials 114 , 116 may be made of paper, cardboard, cloth, mesh, and / or fiber.

[0045] In some example embodiments, substrate 104 is a flexible material (e.g., 50um thin PET foil) and also houses other circuit components (e.g., battery, controller, integrated circuits, etc.). Support 102 may be a 1 mm thick foam spacer on which substrate 104 is folded. In alternative example embodiments, support 102 and substrate 104 may be printed circuit boards.

[0046] In some example embodiments, either or both of the support 102 and the substrate 104 repel a particular substance 118 (e.g., water), depending on which substance 118 the liquid exposure sensing device 100 is designed to monitor. In some examples, the first sensor 106 is on one side of the substrate 104, and the second sensor 110 is on the opposite side of the substrate 104.

[0047] In some example embodiments, the liquid exposure sensing device 100 is permanently attached to the package (eg, via glue or adhesive) and is disposable.

[0048] In the liquid exposure sensing device 100, the first sensor 106 is configured to generate a first signal in response to the liquid phase and / or vapor phase of a substance passing through (i.e., liquid and / or gas diffusion) a reference material 116. The second sensor 110 is configured to generate a second signal in response to the liquid phase and / or vapor phase of a substance passing through the exposure material 114.

[0049] Controller (see Figure 2 ) is coupled to the first sensor 106 and the second sensor 110 and is configured to generate a liquid detection signal in response to a time delay between the first signal and the second signal exceeding a threshold time delay (see, for example, Figure 4-Figure 8 ). With two sensors 106, 110, liquid exposure can be detected using either only two capacitance measurements, only two conductance measurements, or two sets of capacitance and conductance measurements.

[0050] The first sensor 106 and the second sensor 110 may be impedance sensors, capacitive sensors, and / or conductive sensors.

[0051] Note that in some example embodiments, an increase in capacitance measurement is associated with an increase in vapor concentration level (e.g., humidity if the substance is water) because the dielectric strength of the vapor phase 120 of the substance 118 changes with the vapor concentration level. Similarly, an increase in conductance measurement is associated with an increase in condensation of the liquid phase 122 because the condensation acts as a short circuit and shortens the path length between the electrodes, thereby increasing conductance.

[0052] Thus if the first sensor 106 and the second sensor 110 are capacitive sensors and the first signal and the second signal are capacitive signals, the amplitude of the capacitive signals increases in response to the vapor phase of the substance increasing. In some example embodiments, the sensors 106, 110 are configured to measure capacitance at 1 MHz.

[0053] Furthermore, if the first sensor 106 and the second sensor 110 are conductivity sensors and the first signal and the second signal are conductivity signals, the amplitude of the conductivity signal increases in response to the increase of the liquid phase of the substance. In some example embodiments, the sensors 106, 110 are configured to measure conductivity under direct current.

[0054] In some example embodiments, the first sensor 106 is configured in galvanic contact with the reference material 116 , and the second sensor 110 is configured in galvanic contact with the exposed material 114 .

[0055] In some example embodiments, the first sensor 106 and the second sensor 110 are configured to measure both capacitance and conductance; and the controller 206 is configured to generate a liquid detection signal in response to the first signal and the second signal exceeding a threshold capacitance time delay and the third signal and the fourth signal from the first sensor 106 and the second sensor 110 exceeding a threshold conductance time delay.

[0056] The controller 206 includes a memory element that records when and / or whether the liquid and / or vapor phase of a substance passes through the exposure material 114 and / or the reference material 116 during one or more legs of the physical transport journey.

[0057] In some example embodiments, the exposed material 114 and the reference material 116 have the same thickness. In other examples, the materials 114, 116 have different thicknesses. Furthermore, in some example embodiments, the exposed material 114 and the reference material 116 are the same type of material. In other examples, the materials 114, 116 are different. In still other example embodiments, the liquid exposure sensing device 100 uses a matched exposed material 114 and a reference material 116 that are both of the same thickness and made of the same type of material.

[0058] When different types and / or thicknesses of materials 114, 116 are used, adjustments to the circuitry, logic, instructions, etc. of the controller 206 may need to be made in response to the temperature behavior of the materials 114, 116. For example, the dielectric constant may change with temperature, as may the absorption / desorption characteristics. These properties of the materials 114, 116 may also be stored in the memory element.

[0059] Figure 2 2 is an example of a portion 200 of the liquid exposure sensing device 100 before folding. The portion 200 of the liquid exposure sensing device 100 includes a first sensor 106 having a first electrode pair 202, a second sensor 110 having a second electrode pair 204, a controller 206 that may have a memory element (not shown), and a folding region 208.

[0060] The electrode pairs 202 and 204 (eg, "finger capacitors") may be equal sized, made of conductive material, and each having a diameter of about 1 cm. 2 , printed or etched interdigitated electrode pairs with spacing between the finger electrodes similar to the thickness of material 114, material 116 (e.g. etched aluminum, 6 finger electrodes are 0.5mm wide and have 1mm spacing, with 3 finger electrodes connected on each side).

[0061] In various example embodiments, electrodes 202, 204 are not covered by insulating material, thus allowing galvanic contact between electrodes 202, 204 and packaging material. If either of electrode pairs 202, 204 is covered with insulating material, then capacitance measurements can primarily be made from that electrode pair.

[0062] Ground plates 108, 112 may also be printed or etched ground planes of equal size. In some examples, ground plates 108, 112 are larger than the interdigitated electrodes by at least the thickness of support 102 and extend equally on each side (e.g., 12 mm by 12 mm). First ground plate 204 shields exposed material 110 from first electrode pair 202, and second ground plate 208 shields reference material 116 from second electrode pair 206.

[0063] The controller 206 measures the signals from the two sensors 106, 110 at predetermined time intervals to capture any changes in capacitance and / or conductance. In some example embodiments, the controller 206 operates the first sensor 106 and the second sensor 110 at a frequency that best allows detection of wetting caused by one or more liquids to be monitored. For example, frequencies less than 100 kHz can be used to detect liquid water and humidity. The controller 206 can be configured to measure ambient temperature, and simple or complex impedance (i.e., capacitance (μF) and / or conductance (mho)).

[0064] A power source (not shown), such as a printed battery, may also be included on substrate 104 .

[0065] In some example embodiments, the electrode pairs 202, 204 and the ground planes 108, 112 are printed on the flexible substrate 104, which is then folded around the support 102 along the fold line in the fold region 208 and held in place with an adhesive or glue. The reference material 116 is then attached to the first sensor 106, and the second (e.g., exposed material) sensor 110 and the first ground plane 108 are attached to the exposed material 114 (e.g., inside or outside of the package).

[0066] Figure 3 300 is an example of a liquid exposed sensing device 100 after coating. In some examples, a coating 302 is applied that separates the first sensor 106 and the reference material 116 from the surrounding environment. The coating is permeable to the vapor phase 120 of the substance 118, but impermeable to the liquid phase 122. Thus, the coating 302 is vapor permeable, but impermeable to water (e.g., such as a breathable membrane / fabric).

[0067] Figure 4A and Figure 4B 4 is an example first set 400 of first signals from the first sensor 106 and second signals from the second sensor 110. The first set 400 of sensor signals shows regions 402 and 404 of low relative humidity and regions 406 and 408 of increased relative humidity.

[0068] In e.g. Figure 4A In some example embodiments shown in , the capacitance change of the first (e.g., reference material) sensor 106 lags behind the capacitance change of the second (e.g., exposed material) sensor 110 with a time constant based on (e.g., limited by) water vapor diffusion through the outer packaging material.

[0069] If both the inside and outside capacitance and conductance measurements are low (i.e., Figure 4A Area 402 and Figure 4B If the area 404 in the middle is low, then the moisture level is low due to low relative humidity. However, if both the inside and outside capacitances increase compared to the previous measurement cycle, but the conductance remains low (i.e., Figure 4A Area 406 and Figure 4B If the relative humidity increases, the moisture level will increase.

[0070] Figure 5A and Figure 5B An example second set 500 of first signals from the first sensor 106 and second signals from the second sensor 110 is shown. The second set 500 of sensor signals shows a time delay 502, a threshold capacitance time delay 504, a time delay 506, a threshold capacitance time delay 508, and a condensation level 510.

[0071] A change in capacitance of the two sensors 106 , 110 having a time delay 502 less than a threshold capacitance time delay 504 and / or a change in conductance of the two sensors 106 , 110 having a time delay 506 less than a threshold conductance time delay 508 is correlated to a change in relative humidity of the exposed material 114 .

[0072] For example, liquid water vapor may permeate through the exposed material 114 relatively quickly and thereby also change the signals from both sensors relatively quickly.

[0073] If the excessive humidity causes condensation, the conductivity measurement will also have a time delay 506 that is less than the threshold conductivity time delay 508 (ie, both sensors will register a large increase in material conductivity relatively quickly).

[0074] If both the inner and outer capacitances are high and the conductivity increases (see Figure 5A and Figure 5B ), then the increase in relative humidity has led to increased condensation and the capacitance value corresponds to the ambient saturation level.

[0075] Fig. 6A and Figure 6B 6 and 7. The third set 600 of sensor signals is an example of a first signal from the first sensor 106 and a second signal from the second sensor 110. The third set 600 of sensor signals shows a condensation threshold level 602 and a conductance 604. These figures present Figure 5A and Figure 5B The special case where there is a lot of condensation.

[0076] If both inside and outside conductance 604 exceed condensation threshold level 602, then condensation caused by very high humidity will likely cause structural damage to the packaging material. The actual damage threshold 602 depends on the packaging material used (eg, paper packaging may have a lower threshold than cloth packaging).

[0077] In some example embodiments, this situation is associated with a slow rise in temperature (ie, the enclosure is cold and in contact with humid air, and slowly heats up).

[0078] Fig. 7A and Figure 7B 1. An example fourth set 700 of first signals from the first sensor 106 and second signals from the second sensor 110. The fourth set 700 of sensor signals includes a time delay 702 and a threshold capacitance time delay 704.

[0079] The capacitance change with the second (eg exposed material) sensor 110 (see Fig. 7A ), the change in capacitance of the first (ie, reference material) sensor 106 having a time delay 702 greater than a threshold capacitance time delay 704 is associated with the liquid phase 122 of the substance 118 contacting the exposed material 114.

[0080] In this example, the exposed material 114 has been in direct contact with the liquid substance and has become wet as the liquid diffuses through the exposed material 114 (eg, possibly due to, for example, external rain, spillage of internal contents, etc.).

[0081] Because there is substantially no physical contact between the exposed material 114 and the reference material 116, the reference material 116 will not be substantially in contact with the liquid substance and thus the capacitance of the first sensor 106 and the second sensor 110 (see Fig. 7A )There will be a large time delay 702 between responses.

[0082] By comparing time delay 702 to threshold capacitance time delay 704, controller 206 can differentiate between condensation wetting due solely to high humidity and direct liquid wetting which may negatively impact the quality of a device or substance carried and / or surrounded by exposed material 114 (e.g., a package).

[0083] In another example embodiment, if the capacitance of the first sensor 106 is low, the conductance of the first sensor 106 is low, the capacitance of the second sensor 110 is high, and the conductance of the second sensor 110 is low (see Fig. 7A and Figure 7B ), then the exposed material 114 has come into contact with the liquid phase 122 of the substance 118. Either there is a small amount of liquid present here, or this is the early stage of the onset of additional wetting. The time scale is governed by the diffusion of water through the packaging material.

[0084] Thus, by comparing the time delay 702 with the threshold capacitance time delay 704 of the first signal and the second signal, the controller 206 can distinguish between rapid wetting of the exposed material 114 (e.g., via liquid immersion, rain, spillage, etc.) and the exposed material 114 being merely in a wet environment.

[0085] In some example embodiments, wetting causes only the second (eg, on exposed material) sensor 110 to become wet, while the first (eg, reference material) sensor 106 remains dry or at least delayed in becoming wet.

[0086] Fig. 8A and Figure 8B An example fifth set 800 of first signals from the first sensor 106 and second signals from the second sensor 110 is shown. The fifth set 800 of sensor signals includes a time delay 802, a threshold capacitance time delay 804, a time delay 806, and a threshold conductance time delay 808.

[0087] A change in capacitance and / or conductance of first sensor 106 or second sensor 110 having a time delay 802 greater than a threshold capacitance time delay 804 or a time delay 806 greater than a threshold conductance time delay 808 is associated with liquid phase 122 of substance 118 contacting exposed material 114 .

[0088] This example can be understood as a fourth set 700 of sensor signals extended in time (see Fig. 7A and Figure 7B ), thereby generating a fifth set 800 of sensor signals. Here the capacitance signal has reached the ambient saturation level (eg, 100% humidity) (see Fig. 8A ), and now the condensation signal also starts to increase (see Figure 8B ).

[0089] In this example 800, the exposed material 114 has been in direct contact with the liquid substance for a longer period of time than previously. Fig. 7A and Figure 7B The time shown in is long, and as the liquid continues to diffuse through the exposed material 114, the exposed material 114 becomes even more wet.

[0090] These different measurements between the first sensor 106 and the second sensor 110 are associated with the outer packaging material being wetted and not due to an increase in ambient humidity.

[0091] In some example embodiments, the controller 206 makes this determination if the capacitance of the first sensor 106 is low, the conductance of the first sensor 106 is low, the capacitance of the second sensor 110 is high, and the conductance of the second sensor 110 is high (see Fig. 8A and Figure 8B ), then the exposed material 114 experiences both humidity saturation and condensation; while the reference material 116 begins to experience an increase in humidity only due to an increase in local (e.g., inside the package) relative humidity caused by evaporation of the liquid phase 122 of substance 118 from the inner surface of the exposed material 114. Figure 8B It is shown that the first sensor 106 has not measured any condensation because the first sensor 106 has not been wetted.

[0092] It should be noted that in some example embodiments, both condensation and external wetting exposure will result in a small but permanent change in the properties of the exposed material 114 (e.g., value new <> value old). Thus, after a condensation event, both the inside material 114 and the outside material 116 may return to different but still equal measurements (e.g., inside = outside); whereas, in the event of wetting the inside material 114 and the outside material 116 may not return equally to their previous measurements (e.g., inside <> outside). Thus, in such embodiments, even if no measurements by the controller 206 are taken during a wetting event, they may still be detected after a wetting event.

[0093] The above example embodiments can be applied to smart sensors. Packaging (e.g., food, parcels, pharmaceuticals, etc.) manufacturers may also be interested in these example embodiments for measuring various types of moisture. The above example embodiments not only report moisture levels and temperatures, but also distinguish the causes of such moisture (e.g., direct wetting versus ambient humidity).

[0094] Although the above discussion gives an example of a single liquid sensing device applied to a package, other applications are possible. For example, multiple liquid sensing devices can be applied to different locations on the package. In addition, additional and / or redundant liquid exposure sensing devices 100 can be added.

[0095] Although the “wet outside” but “dry inside” embodiments have been generally discussed above, the liquid exposure sensing device 100 may also be applied to “wet inside” but “dry outside” packages for monitoring internal food or drug spillage.

[0096] The liquid exposure sensing device 100 may also be used to monitor an object, food, or device as it passes through various manufacturing steps to ensure quality control.

[0097] The liquid exposure sensing device 100 can also be part of an RFID / NFC tag. An additional antenna would then be needed for communication. This would be similar to the temperature logging NFC tags we have developed in the past few years, but could also monitor moisture. Not considered an essential part of the present invention.

[0098] Unless a specific order is explicitly stated, the various instructions and / or operational steps discussed in the above figures may be performed in any order. In addition, those skilled in the art will recognize that although some example sets of instructions / steps have been discussed, the materials in this specification may also be combined in a variety of ways to produce other examples, and should be understood in the context provided by this detailed description.

[0099] In some example embodiments, these instructions / steps are implemented as functional and software instructions. In other embodiments, the instructions can be implemented using any of logic gates, dedicated chips, firmware, and other hardware forms.

[0100] When the instruction is implemented as an executable instruction set in a non-transient computer-readable or computer-usable medium, the instruction is implemented on a computer or machine programmed with the executable instruction and controlled by the executable instruction. The instruction is loaded for execution on a processor (such as one or more CPUs). The processor includes a microprocessor, a microcontroller, a processor module or a subsystem (including one or more microprocessors or microcontrollers) or other control or computing devices. The processor may refer to a single component or multiple components. The computer-readable or computer-usable storage medium is considered to be a part of an article (or product). An article or product may refer to any manufactured single component or multiple components. As defined herein, non-transient machines or computer-usable media do not include signals, but such media may be able to receive and process information from signals and / or other transient media.

[0101] It will be readily appreciated that the components of the embodiments as generally described herein and illustrated in the accompanying drawings may be arranged and designed in a variety of different configurations. Thus, the more detailed description of the various embodiments as represented in the figures is not intended to limit the scope of the present disclosure, but is merely representative of the various embodiments. Although various aspects of the embodiments are presented in the accompanying drawings, the drawings are not necessarily drawn to scale unless specifically indicated.

[0102] The present invention may be implemented in other specific forms without departing from the spirit or essential characteristics of the present invention. The described embodiments should be considered to be illustrative and non-restrictive in all respects. Therefore, the scope of the present invention is indicated by the appended claims rather than by this detailed description. All changes within the meaning and scope of the equivalents of the claims are included within the scope of the claims.

[0103] References throughout this specification to features, advantages, or similar language do not imply that all features and advantages that can be achieved using the present invention should be or are in any single embodiment of the present invention. Rather, language referring to features and advantages should be understood to mean that a particular feature, advantage, or characteristic described in connection with an embodiment is included in at least one embodiment of the present invention. Thus, discussion of features and advantages and similar language throughout this specification may (but does not necessarily) refer to the same embodiment.

[0104] In addition, the described features, advantages and characteristics of the present invention may be combined in any suitable manner in one or more embodiments. Those skilled in the relevant art will recognize that, in view of the description herein, the present invention may be practiced without one or more of the specific features or advantages of a particular embodiment. In other cases, additional features and advantages may be identified in certain embodiments that may not be present in all embodiments of the present invention.

[0105] Reference throughout this specification to "one embodiment," "an embodiment," or similar language means that a particular feature, structure, or characteristic described in connection with the indicated embodiment is included in at least one embodiment of the present invention. Thus, the phrases "in one embodiment," "in an embodiment," and similar language throughout this specification may, but do not necessarily, all refer to the same embodiment.

Claims

1. A liquid exposure sensing device, characterized in that: include: a first sensor configured to be coupled to a reference material; wherein the first sensor is configured to generate a first signal in response to a liquid phase and / or a vapor phase of a substance passing through the reference material; a second sensor configured to be coupled to the exposed material; wherein the second sensor is configured to generate a second signal in response to the liquid phase and / or vapor phase of the substance passing through the exposed material; and a controller coupled to the first and second sensors and configured to generate a liquid detection signal in response to a time delay between the first signal and the second signal exceeding a threshold time delay; The first sensor and the second sensor are impedance sensors and the first signal and the second signal are impedance signals; or the first sensor and the second sensor are capacitance sensors and the first signal and the second signal are capacitance signals; or the first sensor and the second sensor are conductivity sensors and the first signal and the second signal are conductivity signals.

2. The sensor according to claim 1: It is characterized in that The first sensor is configured to be in galvanic contact with the reference material, and the second sensor is configured to be in galvanic contact with the exposed material.

3. The sensor according to claim 1: It is characterized in that The exposure material is configured to be in direct contact with the liquid phase of the substance before the reference material is in direct contact with the liquid phase of the substance.

4. The sensor according to claim 1: It is characterized in that or the first and second sensors are configured to measure both capacitance and conductance; and The controller is configured to generate the liquid detection signal in response to the first signal and the second signal exceeding a threshold capacitive time delay and the third signal and the fourth signal from the first sensor and the second sensor exceeding a threshold conductance time delay.

5. The sensor according to claim 1: It is characterized in that The controller is configured to generate a liquid condensation signal in response to the first signal or the second signal exceeding an amplitude threshold signal level.

6. The sensor according to claim 1: It is characterized in that The controller includes a memory element that records when and / or whether the liquid and / or vapor phase of the substance passes through the exposure material and / or the reference material during one or more legs of a physical transport journey.

7. The sensor according to claim 1: It is characterized in that further comprising a coating that separates the first sensor and the reference material from a surrounding environment; wherein the coating is permeable to the vapor phase but impermeable to the liquid phase.

8. The sensor according to claim 1: It is characterized in that The first sensor and the second sensor are both responsive to the vapor phase of the substance.

9. The sensor according to claim 1: It is characterized in that further comprising a substrate; Wherein the first sensor is on one side of the substrate and the second sensor is on an opposite side of the substrate.

10. A liquid exposure controller circuit, characterized in that: include: a controller circuit configured to be coupled to the first sensor and the second sensor; wherein the first sensor is configured to be coupled to a reference material and configured to generate a first signal in response to a liquid phase and / or a vapor phase of a substance passing through the reference material; wherein the second sensor is configured to be coupled to an exposed material and configured to generate a second signal in response to the liquid phase and / or vapor phase of the substance passing through the exposed material; and wherein the controller circuit is configured to generate a liquid detection signal in response to a reception time delay between the first signal and the second signal exceeding a threshold time delay; The first sensor and the second sensor are impedance sensors and the first signal and the second signal are impedance signals; or the first sensor and the second sensor are capacitance sensors and the first signal and the second signal are capacitance signals; or the first sensor and the second sensor are conductivity sensors and the first signal and the second signal are conductivity signals.

Images