METHOD AND DEVICE FOR MEASURING AND COLLECTING ENVIRONMENT DATA IN A CLOSED VOLUME

TECHNICAL FIELD

The present invention relates to a device for measuring and storing certain physical quantities relating to atmospheric parameters, among which the concentration of certain gases, and for remote transmission of stored data.

The present invention relates also to a method for detecting and storing certain physical quantities inside physically isolated volumes, for example, hermetically sealed containers, and for transmitting the stored data outside without disrupting the isolation of said volumes.

STATE OF THE ART

There are known apparatuses in meteorology, commonly called "weather stations", for detecting atmospheric parameters, such as temperature, humidity, dew point, speed and direction of the wind, quantity of daily precipitations, etc. Such apparatuses allow to remotely transmit the data detected in real time via a cable connections or wireless or they allow to store the data in data storing means (data logger) included in the detection station; in the second case, the stored data are transferred to the above mentioned data storing means by a permanent or temporary cable connection, usually a serial type one. The weather stations of the above outlined type are suitable for detecting data related to the atmospheric environment, however, they are not suitable for being used to monitor the same parameters within physically isolated volumes, since they are bulky and need to be constantly powered by connecting them to an electrical line.

There are also known other apparatuses for measuring environment physical quantities, such as portable and fixed single-gas e multi-gas detectors, as well as detection units aimed at monitoring working environments; these apparatuses generally signal that particular abnormal or dangerous environmental conditions have been overcome and, should it be required to download the detected and collected data, this can be done via a cable connection between the instruments and the receiving and storing apparatuses, normally consisting of personal computers. The need for physical connection of the above mentioned devices both for their powering and for the download of the data stored therein, limits considerably their application fields.

For example, the US 2007/212792 Al discloses a method and apparatus for measuring the concentration of oxygen in a closed volume, which can be, for instance, a container for food. The device, preferably an handheld type, includes at least an oxygen sensor and temperature sensor, memory means, radio transmission means, and control electronics, situated in a box. In order to make the device work, a luminescent element must be provided inside the closed volume, whose concentration of oxygen is to be measured. The measuring is carried out by placing the device, from the outside of the closed volume, close to the luminescent element, which is excited and its light emission is measured by the sensor included in the device. With the above mentioned device and method, the measurement occurs only when the device is placed sufficiently close to the wall of the closed volume, which moreover, must be transparent so as to allow the light to pass therethrough.

SUMMARY OF THE INVENTION

The object of the present invention is to propose a device for measuring and storing over time some physical quantities related to environmental parameters, which has limited dimensions and weight and allows to read the detected data via radio, in real time or later.

Another object of the present invention is to propose a device for measuring and storing environmental parameters, such as concentration of oxygen, relative humidity and temperature, which has a limited cost and pocket size, is portable and self-powered.

Another object of the present invention is to propose a device for measuring and storing environmental parameters, which can be used for monitoring given physical quantities inside physically isolated volumes, such as hermetically sealed containers, packages, wrappings and the like, and which allows the measured values to be read without breaking the physical isolation of the above mentioned volumes, that is without opening the above mentioned containers, packages, wrappings and the like.

A further object of the present invention is to propose a method for measuring and storing physical quantities inside physically isolated volumes, such as hermetically sealed containers, packages, wrappings or the like, and for transmitting the stored data outside of the above mentioned volumes without breaking the physical isolation of the volumes.

According to an aspect of the present invention, the above objects are achieved by a device for measuring and storing physical quantities, obtained in accordance with claim 1 and including a box, which houses:

at least a sensor for measuring the concentration of a gas, electric storage batteries, non-volatile memory means,

at least a circuit for storing data detected by the sensors in the above mentioned memory means, and

radio receiving-transmitting means;

and in which the above mentioned at least one sensor is housed in the box so that it is able to detect data from the environment surrounding said box.

The above outlined device allows to monitor over time the environment concentrations of at least one gas and is able to transmit the taken measures to external units, without need of any kind of physical connection, neither for powering the device nor for data transmission. This allows using the device in various kinds of applications.

Further characteristics or versions of a device according to the present invention are set forth in the dependent claims.

In particular, the sensor for gas, which can be oxygen, carbon dioxide, carbon monoxide or a nitrogen oxide, is of the electrochemical type.

Advantageously, also a humidity and temperature sensor is provided.

Still advantageously, the radio receiving-transmitting means are of the digital type and work at frequencies above 2 GHz. The digital radio modules integrated on the printed electronic cards have very limited sizes. Moreover, the very high frequencies allow very reduced antennas to be used, likewise integrated on the same electronic printed circuit. Also the transmission powers are very low. The fact that the above mentioned components have very reduced dimensions and extremely low power consumption allows to drastically reduce the device overall dimensions without penalizing its endurance. Advantageously, the circuit for writing the data detected by said sensors in said memory means is suitable also for understanding and managing commands received by said radio receiving-transmitting means for setting and operating the device. According to another aspect of the present invention, the above mentioned objects are reached by a method for measuring and storing physical quantities according to claim 7.

The method of the invention includes introducing a device for collecting environmental data according to the present invention into a given volume, for example, a container, package, wrapping or the like; closing the container in such a way that the device cannot be physically reached without opening the container; measuring and storing, by the device, the environmental parameters related to the inner volume of the container; sending signals to said device, with a request to transmit the data stored therein, by using an external unit, such as a PC, palmtop, smartphone or another unit provided with radio receiving-transmitting means; radio-transmitting the data stored in said device to said external unit, the data transmission request and the data transmission being performed without breaking the isolation of said volume.

Advantageously, the transmission of said radio signals occurs according to certain encodings so that an external unit can receive data from a plurality of devices.

The above outlined method allows use of a device with reduced dimensions, such as the one of the invention, to monitor environmental parameters, in particular the concentration of specific gases, inside the isolated volumes, such as closed packages, wrappings or containers. The method can be advantageously used in various fields, such as packaging, in particular for measuring permeability, and in the logistics. For example, the device can be introduced in the package of a product which is subsequently sent and the recipient can download, without opening the package and before accepting it, the historical report of the registrations made by the device and check whether the transport conditions have been respected (for example, keeping within certain temperature and humidity ranges) and, consequently, accept or not the shipment. In the packaging field, thanks to the device and method of the invention, it is possible to value many characteristics of the container in a non destructive way. For example, by introducing the device in a container for food or beverages, which is subsequently hermetically sealed, it is possible to evaluate over time the state of oxidizing phenomena, absorption or loss of the container with respect to the environment surrounding it.

BRIEF DESCRIPTION OF DRAWINGS

These and other characteristics of the invention will become more easily comprehensible from the following description of a preferred embodiment of the invention, given as a not limiting example, with reference to the enclosed figures, in which:

Figure 1 shows a perspective view of a device according to the invention;

Figure 2 shows a schematic plan view of a main portion of the device of Figure 1 ;

Figure 3 shows a functional block diagram of a device according to the invention associated to an external control unit;

Figure 4 shows a flow chart of an embodiment of the method according to the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

With reference to Figures 1 and 2, an embodiment of a device for measuring and storing environmental parameters 10, according to the present invention, is shown. A box 11, made of plastic material and having very reduced dimensions, houses the components of the device. A printed electronic circuit board 13, on which there are mounted a sensor for gas 14, in particular oxygen, and a relative temperature and humidity sensor 15, is associated to a base body 12 of the box. A covering portion 16 of the box 11 contains housings and apertures for the above mentioned sensors and a housing for electric storage batteries 18, which, conventionally, includes an aperture for the replacement of the electric storage batteries 18, provided with a small access cover 19, comprising also electric contact means for the above mentioned electric storage batteries 18. The base body 12 and covering portion 16 of the box are advantageously snap fit coupled and simply provided with mutual reference means 20. The device 10 of the embodiment shown in Figures 1 and 2 has a box 11, made of plastic material, whose sides are 1 to 5 cm long and, thanks to its solid and shockproof structure, it is particularly indicated to be introduced into containers, or into packages and wrappings, that can be stacked up onto pallets.

With reference to Figures 3 and 4, the electronic components of the device 10 as well as its functions will be now described in a more detailed way, which allow carrying out the method for detecting and storing certain physical quantities, among which at least the concentration of a gas inside physically isolated volumes.

The printed electronic circuit board 13 includes a circuit aimed at storing the data in a non-volatile memory 21. The above mentioned circuits can have more or less advanced functions for processing data detected by the sensors 14 and 15 and for processing data received or to be sent to a radio receiving-transmitting module 22. In particular, the device is provided with a firmware electronic control program, which allows the device functions to be programmed. The radio receiving-transmitting module is of the digital type and preferably works in free frequencies assigned to communications according to the IEEE 802,1 lb or Bluetooth standards, that is frequencies included between 2.4 and 2.5 GHz. The use of these transmission standards limits the transmission radius to about 100 meters in open space (free field), but it allows various advantages. First of all, an antenna module 23, associated to the radio receiving-transmitting means 22 and integrated directly in the printed electronic circuit board 13 can have extremely reduced dimensions. In addition, the transmission of data in digital packets at the above mentioned frequencies involves an extremely limited energy consumption. The oxygen sensor 14 mounted in the device is advantageously of the electrochemical and analogical type and thus the printed electronic circuit board 13 includes an amplification and analogical to digital conversion module 24, such as to allow the processor circuit 21 to read and manage the data coming from the sensor 14. The sensors of the electrochemical type have a practically zero energy consumption, since they produce an electric voltage, whose value depends on the concentration of the gas to be measured. The above mentioned tricks relating to the choice of certain sensors and radio receiving-transmitting means, allow a considerable limitation of the overall dimensions of the device 10. Actually, besides the very reduced dimensions of all other components, thanks to their low energy consumption, it is possible to use electric storage batteries 18, likewise very small and cheap, such as the common lithium batteries, without affecting in any way the device operation endurance, which is in the average of about two years.

Such endurance can be achieved also due the peculiar electronic control program present in the device electronic circuit. In fact, due to this feature, as it will be described in a more detailed way later on, the components of the device are kept deactivated, in stand-by mode, for more than 99% of the device overall operation time. A relative temperature and humidity sensor 15 is advantageously associated to at least one gas sensor 14 since, for many kinds of applications it is necessary to set the device in particular based on the temperature and humidity conditions and their trend over time, in order to obtain reliable and useful measurements by the gas concentration sensor. Also the used temperature and relative humidity sensor 15 has extremely reduced dimensions and energy consumption.

Furthermore, in an alternative and preferred embodiment, the device includes also a pressure sensor and in particular, advantageously, a barometric transducer with operating range from less than 20 to more than 1200 mmbar. Like the temperature sensor, also the pressure sensor has the double function of increasing the number of detectable environmental parameters and allowing a correct detecting of the concentration by the gas sensor. Actually, the gas sensor of the electrochemical type, like any other gas sensor, detects the gas partial pressure, which can be converted in a concentration measure only if the environmental pressure is known. Consequently, the presence of the pressure sensor allows a correct measurement of the gas concentration even if the pressure of the measured environment is not known a priori or varies over time. More particularly, the use of a sensor with the above specified operating range allows, among others, a correct measurement of the concentration of a given gas in a receptacle in which a food vacuum has been created (from 30 to 900 mmbar).

A device 10, as described above, can be used together with an external unit 30, provided with at least a radio receiving-transmitting module 31 and a related antenna 32, having very different purposes, among which the one of carrying out the method according to the present invention. According to an embodiment of the above mentioned method, a device 10 according to what has been previously described, which can be associated to an external unit 30 provided with radio communication means able to communicate with those of the device 10, is housed inside a container or a package C (step 1 10), which is later closed (step 120), with the device remaining included inside the isolated volume of the container C. The container G is aimed at being sent (step 130) and the device 10 has the task to verify that, during the whole sending procedure and possibly also during the initial, final and intermediate storing operations, the product is preserved in the way as agreed. The device, if not in operation before the introduction into the container C, is activated (step 140) by remote control means via radio, which can be the external unit 30 itself or other control means. Once in operation, the device begins to read the values detected by the sensors 14 and 15 and to store them in the non- volatile memory means 21 (step 150). Advantageously, the sampling frequency of the data coming from the sensors 14 and 15 can be adjusted and set by the external unit 30 interacting via radio with the processing circuit 21 of the device. The device, powered by the electric storage batteries 18, keeps on measuring and storing data in its memory means 21. When the container C is received by the recipients (step 160), he can ask via radio by means of the external unit 30 which can be associated to the device, to transmit the data stored in the device (step 170) and the device, according to the request, transmits via radio the stored data to the external unit 30 (step 180). Because of the radio receiving- transmitting function 22 of the device, the transmission of the data to the external unit 30 can occur without opening the container C, that is without breaking the isolation of the volume inside which the device 10 is situated. The data can be transferred from the device 10 to the external unit 30 not only without opening the container C, wrapping or ^' delivery package, but also before accepting the delivery, and in case the downloaded data indicate that anomalous or undesired environmental conditions have occurred inside the container C during the delivery, it is possible to reject the delivery (step 190). The above mentioned check can be performed in few seconds, for example, with the provision of a simple checking program in the external unit 30. The program checks automatically if the data coming from the device satisfy certain requirements, for example, if they remain within the pre-fixed ranges of concentration values of oxygen, humidity and temperature. As it is easy to guess, the above described method is particularly useful and advantageous in the logistics field and especially associated to the packaging of perishable goods or other goods sensible to the environmental conditions.

Although the device has extremely reduced dimensions, so that it can be housed inside single packages of food products, it has an extremely high endurance, of at least two years, during which it continues to work storing the environmental data and transmitting them when requested, without the necessity to open the closed volume, inside which it is housed, so as to keep its space monitored.

This is possible not only due to the choice of the extremely energy efficient components, but also due to a peculiar manner of managing them, implemented by an electronic control program stored in the circuits 21 of the device and reprogrammable by the external unit 30.

The above mentioned electronic program manages the detection and storing of values from the sensors 14, 15 present in the device and radio receiving-transmitting means 22.

In particular, the radio transmission means 22, which is by far the most energy consuming component, is activated at regular time intervals and for a short activation time (few milliseconds), during which it sends a radio signal and stays awaiting for response radio signals from the external unit 30. During the rest of the operating time of the device 10, the radio receiving-transmitting means 22 is deactivated and thus it cannot receive signals coming from the external unit 30. In this way, in practice, the activation time of the radio receiving-transmitting means 22 is less than 1% of the total operation time of the device.

The device 10 is wholly managed by the external unit 30, which is able to communicate with it by its radio receiving-transmitting means 31. The external unit 30 in the device circuit sets a series of programming parameters, among which: interval between two acquisitions of each sensor (how often the sensor must be read and its data stored), sensor activation and deactivation (in order to define which of the present sensors must be acquired), radio transmission power and interval between two activations of the radio receiving- transmitting means 22.

On average, the interval between two activations of the radio receiving-transmitting means 22 varies from 1 to 10 seconds, with an activation time of few (2 - 5) milliseconds, so that, as it has already been stated, the activation time of the radio receiving-transmitting means is less than 1% of the total operation time of the device. As it has already been mentioned, when the radio receiving-transmitting means 22 is activated, it sends a radio signal, which allows the external unit 30 to locate the device, identify it and send it requests for transmission of data and/or programming parameters. If during the activation time, the receiving-transmitting means 22 receives instructions from the central unit 30, it remains active until the received orders are completed, otherwise, if it does not receive instructions, it becomes inactive again after a programmed and predetermined activation time. On the other hand, the interval between two acquisitions can be programmed to last from a minimum of few minutes to a maximum of days, depending on the type of information to collect and also on the total operation time duration, which can be even of some years, as it has already been mentioned. The reading and storing of the data of the sensors 14, 15 is activated periodically with the rate defined by the set interval and consequently, it is brought back to the stand-by state until the subsequent reading.

The memory means 21 has such a capacity as to contain both the programming data and the data detected by the sensors, since the device is activated until the work is finished.

A device according to the invention can be advantageously applied also in the packaging field for performing non destructive controls of the permeability characteristics of certain materials. For example, some plastic materials for food must guarantee a reduced permeability to specific gases, so as to prevent contamination and to preserve the products contained therein in the best possible way. From this point of view, a device according to the invention can include sensors of carbon dioxide, carbon monoxide, nitrogen oxides or still other gases and allows measures, in a not destructive way, of the permeability to the above mentioned gases of containers made of specific materials, with given thickness, surface treatment characteristics or other, and whose inner space condition has been suitably modified, for example, by creating a certain degree of vacuum or by filling it with given pressured gases.

According to the method of the invention, the device can be used to control the permeability of specific materials to given gases not only when they have the shape of containers, which can be hermetically closed, but also when the object whose permeability is to be measured, is in sheets or has other forms. Actually, a device ' according to the invention can be housed inside a test chamber, whose walls are substantially impermeable or have known permeability, and in which such a chamber has an aperture, which can be closed by tightly applying thereon the object, whose tightness is to be measured. Consequently, the test chamber and the sheet of material to be tested applied thereto form a closed volume. Knowing the volume of the test chamber, by monitoring the concentration of the gas in the chamber by means of the device, it is possible to measure the object permeability.

Obviously, other versions can be applied to the device and method of the invention, so as to make it suitable for other specific applications, yet maintaining valid the advantages pointed out until now.

For example, a device having functions similar to those of the above described device 10 could be studied to have still more reduced dimensions or could be studied so that chemically aggressive liquids or substances cannot reach electronic components of the device.

An alternative version of the device box includes a box body made of ABS by a rapid prototyping process, which box body presents in its inside a housing space for a battery and another space for housing the sensors and control electronics. The above mentioned box body is provided with a substantially flat plug, which can be snap fitted and which has a series of slots in correspondence to the housing of the sensors. Thus, the removal of the above mentioned plug allows to reach both the battery compartment and the sensor compartment.

The data can be received-transmitted between the device 10 and the external unit 30 in an encoded form both to prevent unauthorized accesses to the data contained in the device and to allow multiple devices 10 to be associated to a single external unit 30. Moreover, the ^' data transmission from the device 10 to the external unit 30 can also occur in real time during their detection by the sensors.

The external unit 30 can be a dedicated electronic device, or, more advantageously, it can be a palmtop, tablet or another handheld electronic device, provided with radio receiving-transmitting means 31 connected, possibly by an USB interface 33, to processing means, comprising one or more programs aimed at communicating with the device 10.

These and other versions or modifications can be applied to a device and method according to the present invention without departing from the protective scope defined by the following claims.