WO2014195943A1

WO2014195943A1 - An infra-red based method and system for determining integrity of a product

Info

Publication number: WO2014195943A1
Application number: PCT/IL2014/050496
Authority: WO
Inventors: Yoav Weinstein; Eran Sinbar
Original assignee: D.I.R. Technologies (Detection Ir) Ltd.
Priority date: 2013-06-04
Filing date: 2014-06-02
Publication date: 2014-12-11

Abstract

The present disclosure provides a method and system for determining integrity of a product (14), comprising: (a) placing the product between at least one radiation emitting body (16) and one infra-red (IR) sensing arrangement (18) comprising at least one IR sensor, the product comprises a housing being essentially transparent to IR radiation; (b) while the product is at a steady state temperature which is different from the temperature of the radiation emitting body, creating a sensing session comprising sensing by the at least one IR sensor, radiation emitted from the radiation emitting body, at least a portion of the emitted radiation being transmitted through the housing of the product, and (c) generating IR data from the sensed radiation, the IR data being indicative of the integrity of said product; wherein the product is spaced apart from at least the radiation emitting body such that no contact exists therebetween.

Description

AN INFRA-RED BASED METHOD AND SYSTEM FOR DETERMINING INTEGRITY OF A PRODUCT

TECHNOLOGICAL FIELD

The present disclosure concerns the use of infrared imaging for determining, inter alia, quality of products. PRIOR ART

References considered to be relevant as background to the presently disclosed subject matter are listed below:

- US patent application publication No. 2006289766A

- US Patent No. 5,978,691

Acknowledgement of the above references herein is not to be inferred as meaning that these are in any way relevant to the patentability of the presently disclosed subject matter.

BACKGROUND

Infrared thermography (IRT) is a technology that detects radiation in the infrared range of the electromagnetic spectrum (roughly 3,000-14,000 nanometers or 3-14 μπι) and produce images of that radiation. Since infrared radiation is emitted by all objects above absolute zero according to the black body radiation law, thermography makes it possible to see one's environment with or without visible illumination. The amount of radiation emitted by an object increases with temperature; therefore, thermography allows one to see variations in temperature.

US patent application publication No. 2006289766A describe a system for IR thermography based visual inspection of substrates coated with paints and polymers to determine environmental and physical damages such as corrosion and cracks, without the need to remove the paint. US Patent No. 5,978,691 describes a device and method for noninvasively quantifying physiological parameters in blood. The device and method utilize changes in molecular behavior induced by thermal energy of change to facilitate the measurement of the physiological parameters in blood. GENERAL DESCRIPTION

The present disclosure provides, in accordance with a first of its aspects, a method for determining quality/integrity of a product, the method comprising:

placing the product between at least one radiation emitting body and an infra-red (IR) sensing arrangement comprising at least one IR sensor, the product comprising a housing essentially transparent to IR;

while said product is at a steady state temperature which is different from the temperature of the radiation emitting body, creating a sensing session comprising sensing by the at least one IR sensor, radiation emitted from the radiation emitting body, at least a portion the emitted radiation being transmitted through said product, and

generating IR data from the sensed radiation, the IR data being indicative of the integrity of said product;

said method being characterized in that the product is spaced apart at least from the radiation emitting body, such that no direct contact (i.e. no physical contact) exists therebetween or no heating of the housing takes place by the radiation emitting body.

The present disclosure also provides, in accordance with a second aspect, a system comprising:

a base for holding thereon a product comprising a housing;

- at least one radiation emitting body being spaced apart from said base such that upon operation of the system and holding of the product on said base, temperature of said product is maintained at a steady state temperature; at least one IR sensing arrangement comprising at least one IR sensor configured to sense radiation emitted from the at least one radiation emitting body thought at least a portion of the product, when the product is located on its base and being spaced apart from at least the radiation emitting body, such that no physical contact exists therebetween, and to generate IR data corresponding to the sensed radiation;

a processing unit for receiving the IR data from the at least one IR sensing arrangement and providing a signal when said IR data is indicative that the product is defaulted;

a control unit for controlling at least temperature of the radiation emitting body.

Yet further, the present disclosure provides, in accordance with a third aspect, a program storage device readable by a control unit, tangibly embodying a program of instructions executable by the control unit to perform a method for determining content of a product, the method comprising:

placing the product between at least one radiation emitting body and an infra-red (IR) sensing arrangement comprising at least an IR sensor, the product comprises a housing that is essentially transparent to IR, the product being spaced apart from at least said radiation emitting body such that no physical contact exists therebetween;

while said product is at a steady state temperature, the temperature being different from the temperature emitted from the radiation emitting body, creating a sensing session comprising sensing, by the at least one IR sensor, radiation emitted from the radiation emitting body, at least a portion of the emitted radiation being transmitted through said product,

generating IR data from the sensed radiation, the IR data being indicative of the integrity of said product.

Finally, and in accordance with a fifth of its aspects, the present disclosure provides a control unit comprising a computer useable medium having computer readable program code embodied therein for determining integrity of a product, the computer program product comprising:

computer readable program code for causing a sensing session comprising sensing, by at least one IR sensor, radiation emitted from a radiation emitting body, at least a portion of the emitted radiation being transmitted through a housing of said product that is essentially transparent to IR, when being placed between the radiation emitting body and an IR sensing arrangement comprising the at least one IR sensor and being spaced apart from at least the radiation emitting body, wherein the product is at a steady state temperature;

computer readable program code for causing a processing unit to receive sensed IR radiation from the at least one IR sensor and to generate IR data from the sensed radiation, the IR data being indicative of the content of said product.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to better understand the subject matter that is disclosed herein and to exemplify how it may be carried out in practice, embodiments will now be described, by way of non-limiting example only, with reference to the accompanying drawings, in which:

Figs. 1A-1B are schematic illustrations of a system in accordance with an embodiment of the present disclosure comprising either a single (Fig. 1A) or a pair (Fig. IB) of radiation emitting bodies and IR sensors;

Fig. 2 is a schematic illustration of a system in accordance with another embodiment of the present disclosure, comprising an IR sensor and an array of reflecting units, reflecting IR from two radiation emitting bodies;

Fig. 3 is another schematic illustration of a system in accordance with an embodiment of the present disclosure, comprising an IR sensor and an array of reflecting units, reflecting IR from a single radiation emitting body;

Fig. 4 is yet another schematic illustration of a system in accordance with another embodiment of the present disclosure, comprising an IR sensor and an array of reflecting units, reflecting IR from a single radiation emitting body, the system also comprises a mechanism for rotating the product.

Fig. 5 is a schematic illustration of a system in accordance with an embodiment of the present disclosure including a single IR sensor, a single radiation emitting body and a mechanism for rotating the product.

Figs. 6A-6H are IR images of products (HDPE bottles) having different contents within the bottle housing, obtained using a system in accordance with one embodiment of the present disclosure; Figs. 7A-7F are IR images of products being HDPE bottles carrrying two desiccant canisters, obtained at different black body temperatures, using a system in accordance with one embodiment of the present disclosure;

Figs. 8A-8B are images received by an IR sensor (Fig. 8A) in accordance with the invention and a CCS camera (Fig. 8B) of a multi-layered products showing the content of said products.

Figs. 9A-9B are images received by an IR sensor in accordance with the invention (Fig. 9A) and a CCS camera (Fig. 9B) of a multi-layered products showing a defect in a layer of the products.

Figs. 10A-10B are images received by an IR sensor in accordance with the invention (Fig. 10A) and CCD camera (Fig. 10B) showing areas of defected welding, marked by an arrow that are not visible in the CCD camera.

DETAILED DESCRIPTION OF NON-LIMITING EMBODIMENTS

There is often a need in manufacturing process and quality control of products to verify content sealed within a container that is invisible in visible light (i.e. the container is non-transparent in visible light) as well as to determine if the housing holding the content is defaulted (container integrity), for example, include defects in the wall of the container/housing, as further discussed below.

In many occasions, particularly in the chemical industry, including, without being limited thereto, pharmaceutical, cosmetics and agriculture industry, the industrial products are contained within a housing (container) that are essentially transparent in IR spectrum (but may not be transparent in the visible field, e.g. opaque or completely sealed), while their content is at least partially non-transparent in the same IR spectrum. To avoid imaging techniques that involve heating of the product that may damage the product (e.g. the matter within the housing), , the inventors have developed a method and system that allows the exploitation of thermograph principles that does not require actively changing the temperature of the product to be imaged. Specifically, the inventors have unexpectedly found that it is sufficient to provide a background temperature that is different (either higher or lower) from the temperature of the product (i.e. the entire package), in order to visualize the content within the housing or defects in the housing per se, all this, without essentially affecting the temperature of the container and/or the temperature of its content. Thus, in accordance with a first of its aspects, the present disclosure provides a method for determining integrity of a product, the method comprising:

placing the product comprising a housing between at least one radiation emitting body and at least one infra-red (IR) sensing arrangement comprising at least one IR sensor, preferably at least one that is operable to sense radiation within the wavelength range of 2.0μπι to 6.0μπι, the product being essentially transparent to IR the radiation emitting body being spaced apart from said product such that no physical contact exists between the product and at least the radiation emitting body (this is a unique feature of the invention, as no heating occurs on the product, i.e. the housing and/or its content);

while said product is at a steady state temperature which is different from the temperature of the radiation emitting body, creating a sensing session comprising sensing, by the at least one IR sensor, radiation emitted from the radiation emitting body, at least a portion the emitted radiation being transmitted through the product's housing,

In accordance with another aspect, the present disclosure provides a system for performing the above disclosed method. The system comprises:

- a base for receiving a product, the integrity of which is to be detected/determined;

at least one radiation emitting body being spaced apart from said base such that upon operation, radiation emitted from the radiation emitting body is essentially inert to the product (i.e. does not affect the temperature of the product per se);

at least one IR sensing arrangement comprising an IR sensor configured to sense radiation emitted from the at least one radiation emitting body through at least a portion of the product, while the product is at a steady state temperature and is located on said base; and to generate IR data corresponding to the sensed radiation;

- a processing unit for receiving the IR data and providing a signal when said IR data is indicative that the product is defaulted; a control unit for controlling at least temperature of the radiation emitting body.

While in the following description reference is occasionally made only to the method of the present disclosure, it is to be understood as also encompassing and referring to the system of the present disclosure.

In the context of the present disclosure when referring to a "product" or to a "content of a product", or to a "housing of a product" it is to be understood as any product, particularly industrial product, that includes a housing that holds therein content, i.e. the packaging per se, that is made of a material essentially transparent in the IR wavelength or portion thereof, and a void carrying at least one matter/content that is at least partially non-transparent in the same IR spectrum. When the housing holds content, e.g. a chemical or pharmaceutical material, the method is also to be used for determining the integrity/wholeness of the content of the container. Thus, the term "product" is to be understood as encompassing at least one of the packaging/housing, the content within the packaging, and the whole housing with the content therein.

In the context of the present disclosure, when referring to a "product integrity " , and/or "product integrity " and/or "product content integrity " it is to be understood as referring to the packaging/container and/or content completeness, or lack of defects in any one of same. One that lacks integrity or completeness would be considered unusable and thus discarded. The integrity may be in terms of missing or overloading of an element, defected element, defected sealing of the housing, etc.

When referring to an essentially IR transparent container it is to be understood as one allowing the imaging of material through the housing's walls. It does not necessarily mean that the housing is also transparent in the VIS wavelength and in fact, may include material that is viewed as white or opaque or any other semi- or non- transparent material in the visible wavelength range, but using an IR imager, provides a image of the inner space (void) of the housing, its content or of its wall structure.

In the context of the present disclosure a "radiation emitting body" is to be understood to encompass any object that emits thermal radiation. In some embodiments, the radiation emitting body is one that emits electromagnetic radiation. A black body is known as an idealized physical body that absorbs all incident electromagnetic radiation and no electromagnetic radiation passes through it and none is reflected. An example of a black body is one that radiates using a thermal electric cooler (TEC). In some embodiments, the radiation emitting body is an illuminating light, such as a halogen lamp the radiation. In some embodiments, the radiation emitting body is a body that radiates by the expansion of gas at the desired and controlled temperature.

Further in the context of the present disclosure, when referring to "a steady state temperature" , e.g. of the housing, the content of the product or the product as a whole, it is to be understood as being in equilibrium temperature with the surrounding. Thus, when referring to a product in a steady state temperature it is to be understood that the temperature of the product, including at least its content are in equilibrium with room temperature and are essentially not affected by the radiation emitting body (which radiates at a temperature significantly different from that of the product). Further, when referring to a steady state temperature it is to be understood that no active temperature change has been applied onto the product, however, some residual temperature change may exist, e.g. residual heating or cooling from processes that are not related to the radiation emitted from the radiation emitting body. For example, the steady state temperature may encompass some residual temperature change as a result of drying the product, sealing the product (e.g. welding), etc.

Yet further, when referring the container being "spaced apart", it is to be understood to be in a configuration where there is no direct physical contact between at least the radiation emitting body and the product, and that the radiation emitted from the radiation emitting body does not affect or cause a statistically significant change in the temperature of the product. In other words, notwithstanding radiation from the radiation emitting body, the product is maintained in its steady state temperature. The distance between the radiation emitting body and the container will be determined based on the type of the radiation emitting body, the temperature at which it radiates, etc. In some embodiments, the distance between the radiation emitting body and the container is at least 2cm, 5cm, in some other embodiments the distance is at least 10cm, or even at least 15cm, 20cm, 25cm, 30cm and more. In some embodiments, the product is spaced apart from the radiation emitting body and the at least one IR sensor.

Yet further, in the context of the present disclosure, when referring to "IR data" it is to be understood as encompassing one or more IR images, or data processed from one or more IR images or any other IR records that are obtained by the at least one IR sensors. In one embodiment, the IR data comprises one or more IR images of the product and/or its content. In some embodiments, the IR data is retrieved from a single sensing session that is obtained in a time point (image or collection of images taken simultaneously, at essentailly the same time point, to provide IR data in the spatial domain). In some other embodiments, the IR data is retrieved from a combination of separate/distinct sensing sessions. In some other embodiments, the IR data is a collection of IR data obtained from separate sensing sessions, each sensing session comprises obtaining IR data from a different pair of radiation emitting body and IR sensor, each pair providing IR data from a different time point (e.g. when a product is conveyed on a belt such as that illustrated in Figure 4).

The sensing of radiation by the IR sensing arrangement is best achieved when using a wavelength or wavelength band within a predetermined sensing range. A "sensing range" is the wavelength spectrum range at which radiation is sensed by the IR sensing arrangement (i.e. a single or combination of IR detectors). In accordance with a preferred embodiment, the IR sensing arrangement is of a type that senses radiation within at least the spectral range of 2.0-6.0μπι. At times, the IR sensing arrangement is one that is configured to sense radiation within the spectral range of 2.8μπι to 5.4μπι. In some other embodiments, the IR sensing arrangement is one that is configured to sense radiation within the spectral range of 3.0μπι to 5.4μπι. In yet some other embodiments, the IR sensing arrangement is one that is configured to sense radiation within the spectral range of 3.0μπι to 5.0μπι.

Sensing at a particular wavelength range may be achieved either by using a specific sensors or set of sensors, such as a cooled IR detector/s that allows detection within the above preferred ranges, or by using filters to filter out undesired wavelengths or wavelength ranges.

A cooled IR detector, also known as an IR cooled thermal imaging camera has an imaging sensor that is integrated with a cryo-cooler. The cryo-cooler cools down the sensor temperature to cryogenic temperatures. As such, cooled cameras are based on photovoltaic sensors collecting directly the photo-current produced by the scene.

The reduction in sensor temperature provides a reduced thermally-induced noise to a level below that of the signal from the scene being imaged. In this respect, it is noted that an uncooled IR camera is one in which the imaging sensor does not require cryogenic cooling, such as Vanadium oxide (VOx), and Amorphous silicon detectors.

Generally, uncooled IR detectors are based on a microbolometer thermal detector, which consists of an array of pixels, each pixel being a suspended membrane made of a resistive material demonstrating large changes in resistance as a result of minute changes in temperature. In operation, IR radiation with wavelengths between 7.5-14 μπι strikes the detector material, heating it, and thus changing its electrical resistance. This resistance change is measured and processed to create an image. Unlike cooled detectors, microbolometers do not require cooling.

In some embodiments, the cooled IR detectors which may be used in the IR sensing arrangement of the invention are based on array of photodiodes made of semiconductor compounds like Indium Antimonide (InSb) or mercury cadmium telluride (HgCdTe), that need to be cooled down to cryogenic temperatures as operating temperature.

In some embodiments, the IR sensing arrangement comprises a cooled sensor. As shown in the following non-limiting examples, some advantages have been obtained when using cooled IR detectors over the uncooled one.

In some embodiments, the IR detector is characterized by a noise equivalent temperature difference (NETD) of not more than 20mk, at times even not more than lOmK, which is provided by the use of a cooled IR detector with fast integration time (snapshot mode) which is between few microseconds to several milliseconds (this being different from uncooled detectors with long response time).

It is also noted that cooled IR detectors are less sensitive to ambient temperature fluctuations because they work with a cryogenically cooled field stop.

In one embodiment, the IR sensing arrangement comprise at least one cooled InSb detector.

According to some embodiments, IR detector is operable to sense said radiation at ambient temperature.

In it further noted that in the content of the present disclosure, sensing or determine integrity of a container, e.g. detect content of a container or defects in the container's housing etc., cannot be efficiently obtained by using IR sensors configured to sense only in the spectral range of 8-14μηι, or 8-12μηι. In other words, there is a need to at least sense radiation in the mid IR range of 2 to 6μπι, preferably in the ranges of 2.8-5.4μπι so as to achieve best imaging results in accordance with the present invention.

In fact, and as noted above, it has been determined that when imaging a container with an IR sensing arrangement operable to sense radiation at the 2.0-6.0μπι range or the above recited alternative ranges of the sensing range, the visualization of the housing and its content is much better, i.e. the container is much more "transparent" in those range as compared to sensing at the spectral range of 8-14μπι, or of 8-12μπι.

Thermal image may be analyzed by any image processing algorithms known in the art to provide the IR data.

In some embodiments, the product is from the pharmaceutical industry. In some other embodiments, the product is from the cosmetic industry. In yet some other embodiments, the product is from the agricultural industry. In yet some other embodiments, the product is a food product.

The product may comprises, for example, and without being limited thereto, a housing made of polyethylene, in particular, high density polyethylene (HDPE).

In some embodiments, the integrity of the content of the product, i.e. the content within the housing, is to be determined. Such housing would be essentially transparent (or semi-transparent) in the IR wavelength allowing the visualization, in the IR spectrum of its content, which is in turn, at least partially non-transparent to IR.

In some embodiments, the matter/content at least partially non-transparent to IR, is a desiccant unit, such as desiccant canisters. As may be appreciate by those versed in the art of chemical industry, various materials deteriorate or degrade or otherwise are defaulted when exposed to even slight humidity. As such, such materials are packaged with humid scavengers, e.g. one or more desiccant units. In this respect, there is a need in the art to verify that the number, integrity and size as well as other parameters of the desiccant units are according to manufacturing limits. The imaging of the desiccant units in accordance with the present disclosure solves this need as it provides an accurate image of the desiccant unit(s), from which the number of units, size, integrity etc. can be determined.

In some other embodiments, the matter at least partially non-transparent to IR is liquid within the container/housing and the method and system disclosed herein are used to determine level of the liquid in the housing. A level outside the predetermined threshold (e.g. level in the housing/container) will be considered as a defaulted product.

In some embodiments, the integrity of the housing per se is to be determined. This includes, without being limited thereto, determining that the walls of the housing as well as its sealing are intact, without missing elements, cracks, or undesired additional elements.

In some embodiments, the integrity of the housing comprises determining completeness, specifically, existence of defects in the layers forming the walls of a multi-layer bottle. The technology may be used to determine any deviation from an expected pattern, such as deviation from pre-determined transparency through the wall of a bottle, which may be indicative of the absence of a layer. The technology may be used to determine existence of an extra layer, or defect in thickness of a layer. The technology may be used to determine humidity trapped in between layers. The technology may be used to determine any deviation from an expected pattern faulted order of layers etc. The determination may also involve detection of cracks, ruptures or the like in any of the layers.

In operation, initially, the product is placed between at least one radiation emitting body and spaced apart thereof, and an IR sensor. Alternatively, or in addition, the product may be placed between the radiation emitting body and a reflecting unit that forms part of the IR sensing arrangement together with the IR sensor. In this context it is to be understood that the IR sensing arrangement comprises at least one IR sensor, however, it may also include one or more reflecting units and more than one IR sensors. In some embodiments, as will be further discussed below, the product may be placed within architecture of IR sensors and reflecting units, as long as that there is at least one central IR sensor that receives the IR data emitting from the product.

In the context of the present disclosure a "reflecting unit" is a body having reflectance at least in the IR wavelengths spectrum, i.e. capable of reflecting electromagnetic waves. Non-limiting examples of IR reflective materials that may be used to form the reflecting unit include gold coating, aluminum, Plexiglas, hybrid pigmentations (typically a constructions from fibrous clay and dyes) and others. In some embodiments, the reflecting unit is a mirror.

The radiation emitting body acts in the method and system of the present disclosure as a thermal background to the product, being at a temperature difference from the temperature determined for the product. For instance, the radiation emitting body may be heated to a temperature above room temperature so as to provide a hot background or radiate cooled gas to provide a cool background.

In some embodiments, the radiation emitting body is radiates from above the product's opening (before capping the housing) such that the inner volume (void) of the housing is exposed to the radiation. As a result, radiation is transferred from inside the housing outwardly through the walls of the housing.

Once the product is in place (as will be explained further below), a sensing session is actuated. In the context of the present disclosure a "sensing session" denotes the occurrence of at least one IR wavelength sensed by the IR sensor when the radiation emitting body in the background of the product provides radiation at a temperature that is different from the temperature of the product. It is noted that during a sensing session, it is preferable that the temperature of the product is at a steady state temperature. A sensing session includes obtaining IR data with respect to the product. The IR data may include acquiring one or more images of the product, from the same or different angles. The different angles or projections may be obtained e.g. by rotating or tilting the product and/or by rotating one or more components of the system around said product.

In some embodiments, the sensing session takes place at least when the radiation emitting body is at a temperature or radiates at a temperature difference of at least 10°C from the steady state temperature determined for said product. In some embodiments, the temperature of radiation emitting body is not room temperature (i.e. the detection is not under passive thermography conditions where there is no active background radiation of the product).

In some embodiments, during a sensing session the radiation emitting body is at a temperature or radiates at a temperature of at least 40°C or at most 10°C when the temperature determined for the product is about 25°C. The temperature of the product may be determined by any thermal sensor, e.g. a thermometer placed on or in the housing, or by measuring the temperature of the surrounding the product or housing or determining an average room temperature. In some embodiments, the temperature determined for the product is maintained during the sensing session at the same temperature (at most a difference in time of ±2°C).

During a sensing session it is required that the product be between the radiating body and the "field of vision" of the sensor or the reflecting unit. As such, in some embodiments, the product is placed along an imaginary line created between the radiation emitting body and the IR sensor or a reflecting unit.

In some embodiments, more than one reflecting unit and/or IR sensors are used.

To this end, the product is placed between the plurality of reflecting units and sensors. In some embodiments, the plurality of reflecting units is used, and radiation reflected therefrom is sensed by a single IR sensor. The plurality of reflecting units may be arranged juxtaposed along an arc (curved) line counter side to the radiation emitting body, (namely, essentially on the other side of the package). In such configuration, it is essential that the product is positioned such that at least some of the imaginary lines between the reflecting unit or sensor and the radiation emitting body cross the product.

Irrespective of the number of reflecting units used, if at all, the method and system involve at least one IR sensor that is configured to sense the radiation emitted from the emitting body, through the product.

In some embodiments, the method is performed with sensing of radiation by at least two IR sensors, i.e. a system including at least two IR sensors, each forming an imaginary line with a respective radiation emitting body, the imaginary lines intersect with each other. In other words, the method is performed with a pair of a radiation emitting body and reflecting unit or IR sensor (with at least one IR sensor). In such an embodiment, it is preferable that the product is placed at an intersection point between a radiation emitting body and one of an IR sensor and reflecting unit.

In some embodiments employing at least two pairs of radiation emitting bodies and IR sensors (or reflecting units and at least one IR sensor) the at least two imaginary lines formed therebetween are orthogonal to each other. In some embodiments, the method and system comprise a plurality of reflecting units reflecting radiation to a central reflecting unit and at least one IR sensor for sensing radiation emitted from the central reflecting unit.

The method may be performed by applying a single sensing session, e.g., with the radiation emitting body set at a fixed temperature and the product being in a fixed position. However, in some embodiments, several (two or more) sensing sessions may be applied, with each sensing session being different either by the temperature of the radiation emitting body, the positioning of the product or both. For example, the positioning of the product may be changed between each sensing session by one or more of changing the angle (tilting) of the product or shifting the product along its longitudinal axis. The change in the position of the product may be performed by placing it on a carousel.

Similarly, the change in the position of the product with respect to the IR sensor or reflecting unit may be by rotating at least one of the IR sensor, the reflecting unit and radiation emitting body around the product so as to view the product from different perspective projections.

The method and system disclosed herein may use any IR sensor known in the art. This includes IR sensors selected from cooled IR sensors and uncooled IR sensors. The pre-requisite of the IR sensor is that it senses radiation in the IR spectrum (IR wavelength band), including short wave IR (SWIR, 1-3μπι), near IR (NIR, 0.7-1.8μπι), midwave and/or long wave IR, and/or very long IR (Terra Hertz) and any combination of same.

When a cooled IR sensor is used, it may be any one of Indium antimonide (InSb) detectors (e.g. to detect SWIR), indium gallium arsenide (InGaAs) (e.g. to detect NIR) mercury cadmium telluride (HgCdTe, MCT) detectors, quantum well infrared (QWIP) detectors, Type II InAs/GaSb superlattice detectors or any other cooled IR sensors known in the IR detection field.

When an uncooled IR sensor is used, it may be any one of Vanadium oxide (VOx), Amorphous silicon (ASi) or any other uncooled IR sensors known in the IR detection field.

Once a sensing session takes place and the IR sensor senses radiation, processing of the sensed IR is performed by the processing unit. The processing may include also recordation of the sensed IR data, however, it predominantly involves determining, based on a pre-defined condition, if said product is defaulted. For illustration, if a pre-defined condition comprises existence of two and only two desiccant units in a package, a product detected to include any other than two complete desiccant units is determined to be defaulted. According to such embodiment, a defaulted product may also be determined if only two desiccant units exists in the package, albeit, have a size or form (integrity) different from a pre-determined size and form.

In yet another embodiment, a product is regarded to lack integrity if the housing per se is defaulted. To this end, the pre-defined condition may be, any one of the following independent features, each constituting a separate embodiment of the invention: the existence of the correct number of layers forming the housing/container's walls, the thickness of each wall, the existence of a foreign body, such as a metal in the wall, ruptures in one of the layers of the wall, humidity entrapped in the wall and/or in the housing per se, defect in welding sections in the housing. The processing may also involve recordation on a dedicated memory unit of data from a series of sequential product that have been sensed. The recorded data, in turn, may be compared to a predefined process limit or limits and if the recorded data does not fit the process limits, or show a clear trend towards deviation from the pre-defined process limits, a signal is created that may actuate a change in the process line, e.g. to cause calibration of the process or even to create a halt in a manufacturing process. Such data may also be used for statistical applications.

The method and system are also operable by a control unit. In some embodiments, the control unit is operable to at least control the temperature of the radiation emitting body to be at a temperature different from a temperature determined for the product.

In some embodiments, the control unit is operable to actuate a sensing session when the radiation emitting body is controlled to radiate at a temperature difference of at least 10°C from the temperature determined for said package, or at least 40°C or at most 10°C when the temperature determined for the product is about 25°C.

Defaulted product is typically and preferably indicted by an image showing the defect and/or a dedicated signal. The signal may be an audio alert, a recordation of an identification number (serial number) of the defaulted package, a visual alert on a display unit, actuation of a mechanism for removing the product from a process line or any combination of the above.

In some embodiments, the method disclosed herein is performed during a manufacturing process line, at any manufacturing stage. The product may be conveyed on a process conveyer belt and analyzed by the system disclosed herein at any desired process stage. For example, the analysis may be performed before filling a container with material, to determine that the container is suitable for holding the product, after filling the container with the product, to determine that the level or amount of the product is in line with the pre-defined criteria, after placing desiccant units in the container and before sealing; after sealing to determine integrity of the seal or sealing mechanism. Any product determined to be default at the analyzed stage, is removed from the process line before any other process steps are performed thereon. As such, the system for performing the integrity determination may be placed as part of an extended manufacturing process, e.g. in the pharmaceutical industry, the agro-chemical industry, cosmetic industry, food industry and the like.

Also provided by the present disclosure is a control unit comprising a computer useable medium having computer readable program code embodied therein for determining integrity of a product, the computer program product comprising:

computer readable program code for causing a sensing session comprising sensing by at least one IR sensor radiation emitted from a radiation emitting body, at least a portion of the emitted radiation being transmitted through the product, the product being placed between the radiation emitting body and an infra-red (IR) sensing arrangement and spaced apart at least from the radiation emitting body, the IR sensing arrangement comprising at least one IR sensor, wherein the product comprises a housing being transparent or essentially transparent (semi transparent, translucent) to IR;

computer readable program code for causing a processing unit to receive sensed IR radiation from the at least one IR sensor and to generate IR data, such as IR image(s) from the sensed radiation, the IR data being indicative of the integrity of said product. The present disclosure also provides a program storage device readable by a control unit, tangibly embodying a program of instructions executable by the control unit to perform a method for determining content of a product, the method comprising:

placing the product comprising a housing holding said content between at least one radiation emitting body and at least one infra-red (IR) sensing arrangement comprising at least one IR sensor, the housing being essentially transparent to IR, the radiation emitting body being spaced apart from said product such that no physical contact exists therebetween;

while the product is at a steady state temperature which is different from the temperature of the radiation emitting body, creating a sensing session comprising sensing by at least one IR sensor radiation emitted from the radiation emitting body, at least a portion the emitted radiation being transmitted through said product,

generating IR data, preferably one or more IR images of the product, from the sensed radiation, the IR data being indicative of the integrity of said product.

Reference is now made to Figure 1A and IB which are top views of two similar systems in accordance with embodiments of the present disclosure.

Specifically, Figure 1A shows a top view of a system 10 in accordance with an embodiment of the invention comprising comprises a conveyer belt 12 that comprises a base 20 for receiving thereon a product 14; a radiation emitting body 16 being spaced apart (i.e. in distance) from conveyer belt 12 and from base 20 and as such, distant from product 14. The radiation emitting body 16 is paired with a first IR sensor 18, and is placed in counterpose to the radiation emitting body 16, with respect to base 20. Similarly, in this embodiment.

The IR sensor 18 is configured to sense radiation emitted from at least a portion of product 14, when the product 14 is located on its base 20 and to generate IR data corresponding to the sensed radiation.

In this non-limiting embodiment, the radiation emitting body 16 IR sensor 18 form an imaginary orthogonal line, illustrated as arrows 26.

The system 100 also comprises a processing unit 22 embedded within a control unit 24, the processing unit 22 being configured to receive IR data and provide a signal when said IR data is indicative that product 14 is defaulted. The control unit 24 is configured to control the system operation, including, at least temperature of radiation emitting body 16. Other functionalities of the control unit 24 may include operation of the IR sensor 18, such as exposure time, number of IR images captured during a sensing session etc.

Reference is now made to Figure IB which is a top view of a system 100 in accordance with another embodiment of the present disclosure, being similar to embodiment of Figure 1A, albeit with two pairs of radiation emitting bodies and IR sensors.

Specifically, system 100 comprises a conveyer belt 102 that holds a base 120 for receiving thereon a product 104; a first radiation emitting body 106a and a second radiation emitting body 106b (the radiation emitting body collectively referred to by reference numeral 106), both being spaced apart from base 102. The first radiation emitting body 106a is paired with a first IR sensor 108a, and is placed in counterpose to the radiation emitting body 106a, with respect to base 102. Similarly, in this embodiment, the second radiation emitting body 106b is paired with a second IR sensor 108b, and is placed in counterpose to the radiation emitting body 106b, with respect to base 102.

The first IR sensor 108a and the second IR sensor 108b (collectively referred to by reference numeral 108) are each configured to sense radiation emitted from at least a portion of product 104, when the product 104 is located on its base 102 and to generate IR data corresponding to the sensed radiation.

In this non-limiting embodiment, the pairs of first and second radiation emitting bodies 106a, 106b and respectively first and second IR sensors 108a and 108b form imaginary orthogonal lines, illustrated as arrows 111a and 111b, respectively, that intersect at the position of the product 104.

The system 100 also comprises a processing unit 122 embedded within a control unit 124, the processing unit 122 being configured to receive IR data and provide a signal when said IR data is indicative that product 104 is defaulted. The control unit 124 is configured to control the system operation, including, at least temperature of each of radiation emitting body 106a and 106b. Other functionalities of the control unit 124 may include operation of the IR sensors 108a and 108b, such as exposure time, number of IR images captured during a sensing session etc. Figure 2 provides a top view of a system 200 in accordance with a further non-limiting embodiment of the present disclosure. For the sake of simplicity, like reference numerals to those used in Figure 1, shifted by 100 are used in Figure 2 to identify components having a similar function. For example, reference number 206a in Figure 2 is a radiation emitting body having the same function as radiation emitting body 106a in Figure 1.

System 200 includes a single IR sensor 208 that is configured to sense radiation emitting from an array of mirrors (reflecting units) 216a, 216b. The system also includes a semitransparent mirror 218 so as to allow splitting a beam received by the semitransparent mirror into two electromagnetic beams, each being radiated to a different direction (different IR sensor or further reflecting unit). In System 200 only one split from each beam is illustrated.

System 200 also includes two radiation emitting bodies 206a and 206b, with the reflecting units 216a, 216b and 218 and radiation emitting bodies being on opposite sides of conveyer (base) 202 and consequently of product 204. Further, reflecting units 216a, 216b and semitransparent reflecting unit 218 are arranged such that radiation emitted from radiation emitting bodies 206a and 206b passes product 204, and is further reflected from reflecting units 216a, 216b and 218 to reach and be sensed by a single IR sensor 208. IR radiation emitted from radiation emitting bodies 206a and 206b and eventually sensed by the IR sensor 208 is in the direction of arrows 211a and 211b, respectively.

An alternative configuration for a system in accordance with the present disclosure is provided in Figure 3. For the sake of simplicity, like reference numerals to those used in Figure 2, shifted by 100 are used in Figure 3 to identify components having a similar function. For example, reference number 306a in Figure 3 is a radiation emitting body having the same function as radiation emitting body 206a in Figure 2.

Specifically, Figure 3 illustrates a system 300 comprising a single radiation emitting body 308, with an array of four reflecting units (mirrors) 316a, 316b, 316c and 316d, and two semitransparent reflecting units 318a and 318b. As illustrated, reflecting units 316a, 316b, 316c and 316d, and two semitransparent reflecting units 318a and 318b are arranged such that some are on the same side of the conveyer belt (base) 302 as the radiation emitting body 308 and some are on the opposite side of the base 302. The direction of IR radiation that is emitted from radiation emitted body 306 and eventually sensed by IR sensor 308 is illustrated by arrows 311a and 311b.

As noted above, the base holding the product may be configured to change position of the product between two or more sensing sessions, a change in position being one or more of tilting the product or shifting the product along its longitudinal axis. In this connection, reference is made to Figure 4 showing a system 400, similarly, including a conveyer belt 402, two reflecting units (mirrors) 416a, 416b and two semitransparent reflecting units 418a and 418b.

System 400 also includes a mechanism 430 for shifting product 404 along its longitudinal axis X. Mechanism 430 may be a carousel configured to swirl the product 404 by any angle within a 360° range. Preferably, the shifting is by an angle between 10° and 90°. Figure 4 provides an illustration of product 404 at two time points, product 404 at a first time point (to) and the same product 404 at time point (ti), being 4 seconds after to]. In one embodiment, the carousel is configured to shift product 404 by 90° along axis X.

A simplified embodiment to Figure 4 is provided in Figure 5, where a system 500 includes a single radiation emitting body 506, a single IR sensor 508 and a mechanism 530 for shifting product 504 along its longitudinal axis X.

DESCRIPTION OF SOME NON-LIMITING EXAMPLES Example 1: Visualization of content of package

Experimental System Configuration

The system employed in this non-limiting example included:

IR sensor: Two uncooled IR cameras, Bird 384 384x288 pixel, 25 μπι pitch, VOx, un-cooled microbolometer detector, operating at LWIR (8-14μπι) (SCD product);

Radiation emitting body: 7" extended area black boy model SR-800R (CI systems);

Product: HDPE bottle containing two desiccant canisters (Example 1) or inhaler including HDPE housing for the inhalation device (Example 2). The two IR cameras were positioned 90° one with respect to the other and in counter position to the black body with which each camera is paired, as illustrated in Figure 1.

The distance between the black bodies and the product was 17cm and the distance between the IR cameras and the product was 38cm.

Visualization of number of desiccant canisters in package

In this example the number of desiccant canisters in a container (the product) was determined. A product with other than two desiccant canisters was determined to be faulted. To this end, containers with no (0), single (1), two (2) or three (3) desiccant canisters were imaged. The temperature of each of the black bodies was fixed to 50°C.

The results are shown in Figures 6A-6H (number of desiccant canisters in brackets), with Figures 6A (0), 6C (1), 6E (2) and 6G (3) being generated from a first IR camera, and Figures 6B (0), 6D (1), 6F (2) and 6H (3) generated from a second IR camera.

The combination of Figures from two IR cameras provides an accurate determination of the number of canisters in the package. Notably, at times, an image from a single camera may provide a falls indication, such as in Figure 6E or 6G, which images, respectively, a single canister or only two canisters, when in fact the container of Figure 6E includes two canisters, and the container of Figure 6G includes three canisters. Therefore, the additional image from a different angle allows for the correct determination.

In a further experiment, the effect of temperature of the black body on the accuracy of determination was determined. Specifically, a container with two desiccant canisters was images using the experimental system described above, with each image being acquired using a different black body temperature, namely, 10°C, 15°C, 25°C (room temperature), 35°C and 50°C. The results are presented in Figures 7A (10°C), 7B (15°C), 7C (25°C), 7D (35°C), 7E (40°C) and 7F (50°C). As evident, at temperatures that are at least 10°C different from the temperature of the surrounding (room temperature) the content of the packages is clearly visualized. However, at room temperature (passive thermography), it is impossible to detect the content of the package. Visualization of an inhaler content

In a different experiment conducted using the same experimental system described above, an inhaler device was imaged from two different angles using two uncooled IR sensors (orthogonal) and unless stated differently, the radiation emitting unit set to a temperature of 50°C. Images (not shown) generated with or without illumination with an IR lamp (red SYLVANIA, lOOwatt) and a InSb detector was tuned for the NIR region (which may be replaced by an InGaAs detector); or only with a CCD camera revealed that detection in the desired NIR region (using the InSb detector) allowed to image content within the sealed housing of the inhaler. Example 2: Multi Layered Polyethylene Bottles

Experimental System Configuration

The system employed in this non-limiting example included:

IR sensor: cooled IR camera, 512x640 pixel, 15μπι pitch, InSb, operating at MWIR (3-5um) (SCD product);

- Radiation emitting body: 7" extended area black boy model SR-800R (CI systems);

Product: triple layered bottle comprising a thick polyethylene external and inner layers (of about 500μπι) sandwiching a central thinner layer comprising an ethyl vinyl alcohol (EVOH) copolymer (about 50μπι thick). The IR camera was positioned opposite to the radiation emitting body, with the bottle therebetween. The distance between the radiation emitting body and the bottle was 17cm and the distance between the IR camera and the bottle was 38cm.

Visualization of object in a multi- layer bottle's internal void

A finger was inserted into the inner void of the multi layered bottle via the bottles top opening and while at the pre-set distance from the black body (radiation body), the bottle was images with the IR camera or a CCD camera.

Figures 9A and 9B are respectively, the IR image and VIS image of the bottle and finger, showing that IR imaging, at the spectral range of 3-5μπι provided a clear image of the content of the bottle, while regular CCD camera was blind to this content. Notably, imaging at NWIR (l-3μm) or LWIR (8-14μπι) provided results similar to those with CCD camera, i.e. it was not possible to image the content of this particular type of multi-layered bottle which was found to be transparent only at 3-5μπι.

Example 3: Welding quality in polyethylene (PE) bags

Experimental System Configuration

The system employed in this non-limiting example included:

Radiation emitting body: 7" extended area black boy model SR-800R (CI systems);

Product:- plastic bags for sterialized products with sealing by welding;

Visualization of defects in welding

Figure 10A shows glue spilled from the welding zone (see arrow) that is not images by CCD camera of Figure 10B(see arrow).

Claims

CLAIMS:

1. A method for determining integrity of a product, the method comprising

placing the product between at least one radiation emitting body and one infra-red (IR) sensing arrangement comprising at least one IR sensor, the product comprising a housing essentially transparent to IR radiation;

while said product is at a steady state temperature which is different from the temperature of the radiation emitting body, creating a sensing session comprising sensing by the at least one IR sensor, radiation emitted from the radiation emitting body, at least a portion of the emitted radiation being transmitted through the housing of the product, and

wherein the product is spaced apart from at least the radiation emitting body such that no contact exists therebetween.

2. The method of Claim 1, comprising actuating a sensing session when the radiation emitting body radiates at a temperature difference of at least 10°C from the steady state temperature determined for the product.

3. The method of Claim 1 or 2, comprising causing radiation from the radiation emitting body to be at a temperature of at least 40°C or at most 10°C when the temperature determined for the product is about 25°C.

4. The method of Claim 3, wherein said radiation emitting body is a true blackbody having an emissivity of 1.0.

5. The method of any one of Claims 1 to 4, wherein said radiation emitting body thermally radiates by expansion of gas.

6. The method of any one of Claims 1 to 5, wherein said IR sensing arrangement comprises the at least one IR sensor and at least one reflecting unit, the reflecting unit being configured to reflect radiation to the at least one IR sensor.

7. The method of Claim 6, comprising placing the product along an imaginary line formed between the radiation emitting body and the at least one IR sensor or the at least one reflecting unit.

8. The method of any one of Claims 1 to 6, comprising sensing radiation by at least two IR sensors that form imaginary lines when co-aligned with, respectively, at least two radiation emitting bodies, each being spaced apart from said product, the imaginary lines intersect with each other.

9. The method of any one of Claims 1 to 6, comprising placing the product at an intersection point between the radiation emitting body and the at least one IR sensor or a reflecting unit configured to reflect radiation to the at least one IR sensor.

10. The method of Claim 8, wherein the at least two imaginary lines are orthogonal to each other.

11. The method of any one of Claims 1 to 10, comprising a plurality of reflecting units reflecting radiation to a central reflecting unit and the at least one IR sensor for sensing radiation emitted from the central reflecting unit.

12. The method of any one of Claims 1 to 11, comprising two or more sensing sessions, and changing position of the product between each sensing session, a change in position being one or more of tilting the product and shifting the product along its longitudinal axis.

13. The method of Claim 6, wherein at least one of the IR sensor and the reflecting unit are configured to rotate around said product so as to sense radiation from at least to directions respective to said product.

14. The method of any one of Claims 1 to 13, wherein the at least one IR sensor senses radiation at least in the wavelength spectrum of 2.0μπι to 6.0μπι.

15. The method of Claim 14, wherein said at least one IR sensor is a cooled IR sensor.

16. The method of Claim 14, wherein the cooled IR sensor is selected from the group consisting of Indium antimonide (InSb) detectors, mercury cadmium telluride (HgCdTe, MCT) detectors, quantum well infrared (QWIP) detectors, Type II InAs/GaSb superlattice detectors.

17. The method of any one of Claims 1 to 16, comprising processing said IR data of the product and determining based on a pre-defined condition if said product is defaulted.

18. The method of Claim 17, wherein said processing comprises providing a signal when said product is defaulted.

19. The method of Claim 18, for determining integrity of content within the housing of the product.

20. The method of Claim 19, wherein the content comprises desiccant units and said method comprises detecting integrity of the desiccant units in the housing, wherein said processing comprises determining that at least one pre-defined condition is fulfilled if one or more of the number of detected desiccant units, size of detected desiccant units and integrity of said detected desiccant units in the container is equal to, respectively, expected number, size and integrity.

21. The method of any one of Claims 1 to 20, comprising determining integrity of said housing.

22. The method of Claim 21, wherein said housing is a multi-layer container, and said method comprises determining defects in at least one layer of said container.

23. The method of any one of Claims 1 to 22, comprising sensing radiation while the housing is transported along a manufacturing process line.

24. The method of Claim 23, comprising discharging a product from the manufacturing process line when said one or more IR images are indicative that the product is defaulted.

25. A system comprising:

a base for holding thereon a product comprising a housing; at least one radiation emitting body being spaced apart from said base such that upon operation of the system and holding of the product on said base, temperature of said product is maintained at a steady state temperature;

at least one IR sensing arrangement comprising at least one IR sensor configured to sense radiation emitted from the at least one radiation emitting body thought at least a portion of the product, when the product is located on its base and being spaced apart from at least the radiation emitting body, such that no physical contact exists therebetween, and to generate IR data corresponding to the sensed radiation; a processing unit for receiving the IR data from the at least one IR sensing arrangement and providing a signal when said IR data is indicative that a content of the container is defaulted;

26. The system of Claim 25, wherein said radiation emitting body is a true blackbody.

27. The system of Claim 25, wherein said radiation emitting body thermally radiates by expansion of gas.

28. The system of any one of Claims 25 to 27, wherein said IR sensing arrangement comprises the at least one IR sensor and at least one reflecting unit, the reflecting unit being configured to reflect radiation to the at least one IR sensor.

29. The system of Claim 28, wherein the base is located along an imaginary line formed between the radiation emitting body and the IR sensor or between the radiation emitting body and a reflecting unit configured to reflect the radiation to the at least one IR sensor.

30. The system of Claim 29, comprising a plurality of reflecting units, with at least part thereof being co-aligned with at least one IR sensor or with the at least one radiation emitting body.

31. The system of any one of Claims 25 to 30, comprising at least two IR sensors, each being co-aligned with the base and respective radiation emitting bodies to form, respectively, at least two imaginary lines, the imaginary lines intersect with each other.

32. The system of Claim 31 , wherein the at least two imaginary lines are orthogonal to each other.

33. The system of any one of Claims 25 to 32, comprising a plurality of reflecting units configured to reflect radiation to a central reflecting unit, and at least one IR sensor configured to sense radiation emitted from at least the central reflecting unit.

34. The system of any one of Claims 25 to 33, wherein said base is moveable to change, between two or more sensing sessions the position of the container received therein, a change in position being at least one or more of tilting the product and shifting the product along its longitudinal axis.

35. The system of any one of Claims 28 to 34, wherein at least one of the IR sensor and reflecting unit in the IR sensing arrangement is configured to rotate around said product, such that upon operation, radiation is sensed from at least two directions of said product.

36. The system of any one of Claims 25 to 35, wherein the at least one IR sensor senses radiation at least in the wavelength spectrum of 2.0μπι to 6.0μπι.

37. The system of Claim 36, wherein the at least one IR sensor is a cooled IR sensor.

38. The method of Claim 37, wherein the cooled IR sensor is selected from the group consisting of Indium antimonide (InSb) detectors, mercury cadmium telluride (HgCdTe, MCT) detectors, quantum well infrared (QWIP) detectors, Type II InAs/GaSb superlattice detectors, InGaAs.

39. The system of any one of Claims 25 to 38, wherein said processing unit is operable to receive from the IR sensor IR data of at least content within the housing of the product and determining based on a pre-defined condition if the content is defaulted.

40. The system of any one of Claims 25 to 38, wherein said processing unit is operable to receive from the IR sensor IR data of at least the integrity of the product and determining based on a pre-defined condition if the product is defaulted.

41. The system of Claim 39 or 40, wherein said processing unit is operable to provide a signal when the product is defaulted.

42. The system of any one of Claims 25 to 41, wherein said control unit is operable to control the temperature of the radiation emitting body to be at a temperature different from a temperature determined for the product, while the product is at a steady state temperature.

43. The system of Claim 42, wherein said control unit is operable to actuate a sensing session when the radiation emitting body is controlled to radiate at a temperature difference of at least 10°C from the temperature determined for said product.

44. The system of Claim 43, wherein said control unit is operable to control temperature of the radiation emitting body to be at least 40°C or at most 10°C when the temperature determined for the product is about 25°C.

45. A program storage device readable by a control unit, tangibly embodying a program of instructions executable by the control unit to perform a method for determining integrity of a product, the method comprising:

placing the product between at least one radiation emitting body and an infra-red (IR) sensing arrangement comprising at least on an (IR) sensor, the product comprising a housing being essentially transparent to IR, the radiation emitting body being spaced apart from said product such that no physical contact exists therebetween;

while said product is at a steady state temperature which is different from the temperature of the radiation emitting body, creating a sensing session comprising sensing by the at least one IR sensor radiation emitted from the radiation emitting body, at least a portion the emitted radiation being transmitted through said product,

46. A control unit comprising a computer useable medium having computer readable program code embodied therein for determining integrity of a product, the computer program product comprising:

computer readable program code for causing a sensing session comprising sensing by at least one IR sensor radiation emitted from a radiation emitting body, at least a portion the emitted radiation being transmitted through the product being placed between the radiation emitting body and an IR sensing arrangement and spaced apart from at least the radiation emitting body, the product comprising a housing being essentially transparent to IR, and the IR sensing arrangement comprising the at least one IR sensor, wherein the product is at a steady state temperature;