WO2019002552A1

WO2019002552A1 - Portable alarm device and system

Info

Publication number: WO2019002552A1
Application number: PCT/EP2018/067586
Authority: WO
Inventors: Morten Revill
Original assignee: Ejector As
Priority date: 2017-06-29
Filing date: 2018-06-29
Publication date: 2019-01-03

Abstract

The invention relates to a portable alarm device (100) and a related system configured to monitor at least one physical parameter of an object or in an environment. The portable alarm device comprises a disposable or chargeable electric energy storage unit (6); at least one sensor (2) configured to monitor said at least one parameter; at least one alarm (4); a microcontroller (3) configured to activate said at least one alarm if the at least one sensor detects a value of said at least one parameter that exceeds a preset parameter threshold value; a casing (1) enclosing the at least one sensor, the at least one alarm and the microcontroller; and a fastener (9) for non-permanently attaching the casing to or positioning the casing in an environment in which said at least one parameter is to be monitored.

Description

PORTABLE ALARM DEVICE AND SYSTEM

Field of the invention

The present invention relates to a portable alarm device for monitoring a physical parameter, e.g. temperature and/or acceleration, and for activating an alarm if the physical parameter exceeds a predefined threshold value.

The present invention also relates to an alarm system comprising such a portable alarm device.

In particular, the present invention relates to a system that may be used together with electric devices, in particular chargeable and portable devices, such as cellular telephones and computer tablets, to monitor such devices with respect to a physical entity, e.g. temperature and/or acceleration. The system may also be used to monitor an environment, e.g. the interior of an automobile, for triggering an alarm related to said physical entity.

Background For a long time, it has been known that chargeable electric devices, such as cellular telephones and computer tablets, may overheat, melt, catch fire or even explode. Similar problems are associated with electric chargers for such devices, where it lately has been shown that up to a quarter of the all cellular telephone chargers may be defective and likely to overheat. One of the problems in this respect is that the danger associated with overheating is unpredictable in that fire and explosion in such devices due to overheating may affect anyone at any time. Fire or explosion may arise both during charging and use of such devices, and may threaten human lives or cause damages to goods and property. Another factor in this respect is that many of these devices, e.g. cellular telephones, are used or charged in or next to the bed during night-time. Such usage is a problem, and statistics show that domestic fires, material damages and, in some instances, loss of human lives, are due to mobile devices or its chargers overheating in or beside the bed during night-time.

Other situations that are demanding to monitor are dogs and children in automobiles, or babies in baby carriages, that become warn during summertime.

Application software or apps, i.e. computer programs designed to run on a mobile device such as a cellular telephone or tablet, that can monitor parameters associated with the battery of the mobile device, including its temperature, are previously known. Also, different types of fire, smoke and/or heat detectors are generally known and are commonly mounted in buildings, including in domestic homes. Such devices must usually be mounted by trained personnel, e.g. by an electrician or a trained installer, e.g. employed by a security company, and must usually be mounted in predefined locations in a building.

However, neither of these systems are particularly flexible.

Consequently, there is a need for a portable alarm device that can be set-up easily and used to monitor a parameter, in particular temperature, in an object, e.g. a cellular telephone, or in an environment, in particular inside an automobile or in a baby carriage.

The present invention seeks to improve on this situation and is directed to a portable alarm device and a system comprising such a portable alarm device that may solve or at least reduce this problem.

An object of the present invention is to bring forth a portable alarm device configured to monitor at least one parameter which may be used to monitor temperature in objects, such as cellular telephones, or in automobiles and baby carriages.

Another object of the present invention is to provide a system comprising such a portable alarm device.

Summary of the invention

A first aspect of the present invention relates to a portable alarm device configured to monitor at least one physical parameter of an object or in an environment, said portable alarm device comprising: - a disposable or chargeable electrical energy storage unit;

at least one sensor configured to monitor said at least one parameter; at least one alarm; a microcontroller configured to activate said at least one alarm if the at least one sensor detects a value of said at least one parameter that exceeds a preset or predefined parameter threshold value;

a casing enclosing the at least one sensor, the at least one alarm and the microcontroller; and a fastener for non-permanently attaching the casing to or positioning the casing in an environment in which said at least one parameter is to be monitored. Said at least one parameter may comprise temperature, in which case the at least one sensor may comprise a temperature sensor. The at least one parameter may also, or in addition, comprise acceleration, in which case the at least sensor may comprise an accelerometer. The fastener may comprise at least one of a magnet, an adhesive tape or glue and a hook-and-loop fastener, i.e. Velcro-type fastener. If said at least one parameter comprises temperature, the fastener may advantageously be thermally conductive, thus allowing the temperature of an object to which the portable alarm device is attached to be efficiently transferred from the object to the portable alarm device.

Said at least one alarm may comprise a visible alarm, a tactile alarm and/or an audible alarm. The tactile alarm and/or the audible alarm may comprise a piezoelectric sounder, which is also known in the art as a piezoelectric buzzer or beeper. If the tactile alarm and/or the audible alarm comprises a piezoelectric sounder, the piezoelectric sounder may advantageously be positioned adjacent but at a distance from the inside wall of the casing so that a resonance cavity is formed between the piezoelectric sounder and the casing.

Said disposable or chargeable electrical storage unit may comprise a disposable button battery. If the energy storage unit is chargeable, a solar cell film may be arranged on the outside surface of the casing to charge the storage unit. If the portable alarm device is chargeable by external means, e.g. using an electric charger, the portable alarm device may comprise a charging port for receiving a charging connector, e.g. in the form of a micro Universal Serial Bus (USB) connector. However, the energy storage unit, if chargeable, may alternatively be charged using wireless conductive charging means.

The portable alarm device may be configured to be non-permanently attached to a physical object for monitoring said at least one parameter of that object. For example, the portable alarm device may be configured to be attached to a mobile device comprising a rechargeable battery, e.g. a cellular telephone, for monitoring the temperature of the mobile device, or to an electric charger for monitoring the temperature of the electric charger.

The temperature sensor may comprise a heat sensing plate or an area comprising a thermic sensor capable of monitoring heat. The temperature sensor may be positioned close to or at the inside wall of the casing, e.g. at a bottom of the casing, thus allowing the temperature of a physical object to be monitored to be efficiently transferred to the temperature sensor when the portable alarm device is attached to the object.

In addition, or alternatively, the portable alarm device may be arranged to monitor said at least one physical parameter in a predefined environment or setting, e.g. the temperature inside an automobile or the temperature inside and/or the acceleration of a baby carriage. For example, the portable alarm device may comprise a temperature sensor configured to monitor ambient air temperature, i.e. the temperature of the air surrounding the portable alarm device.

The casing may display at least one through-opening allowing ambient air access into the casing. The portable alarm device may be configured to detect different threshold values of the at least one parameter. For example, the portable alarm device may be configured to detect when the temperature exceeds a first preset or predefined temperature threshold value, and also to detect when the temperature exceeds a second preset or predefined temperature threshold value. The portable alarm device is arranged to activate the alarm when said preset or predefined threshold value or values of said at least one physical parameter is/are exceeded. Activating the alarm or alarms may comprise activating a visual, an audible and/or a tactile alarm in the portable alarm device. For example, the portable alarm device may be configured to activate a first alarm when a temperature sensor of the portable alarm device detects that the temperature exceeds a first preset or predefined temperature threshold value, and to activate a second alarm when the temperature sensor detects that the temperature exceeds a second preset or predefined temperature threshold value.

The portable alarm device may comprise a communication module configured to transmit a wireless alarm activation signal when the at least one sensor detects a value of said at least one parameter that exceeds a preset or predefined parameter threshold value, and a second aspect of the present invention relates to a system comprising a first portable alarm device being of the above-described type and at least one second portable alarm device being configured to receive the wireless alarm activation signal transmitted from the first portable alarm device and, in response to the received wireless alarm activation signal, activate a visible, tactile and/or audible alarm in the second portable alarm device, thus allowing an alarm to be triggered at a distance from the first portable alarm device.

For example, if the first portable alarm device is positioned inside an automobile in which the temperature starts to rise, e.g. due to solar radiation, the alarm may not necessarily be triggered only in the portable alarm device, but may alternatively, or in addition, be triggered in a second portable alarm device carried by the owner of the automobile, which second portable alarm device is in communication with but physically separated from the first portable alarm device in the automobile, thus alerting the owner of the automobile that the temperature in the automobile has risen above the preset or predefined threshold value.

Such a combination of a first and a second portable alarm devices may be used, for example, to alert an owner visiting a shopping centre that the temperature inside his automobile parked outside the shopping centre has risen above a predefined temperature, thus preventing a parked automobile in which there is a child or a dog becoming a death trap.

Communication between the first portable alarm device and the second portable alarm device may advantageously be wireless, e.g. realised using any communication system or communication standard known in the art, e.g. Wi-fi, Bluetooth, Bluetooth Low Energy (BLE), ZigBee, radio signals, or the mobile phone network. It may be preferred, however, that the wireless alarm activation signal is transmitted from the first portable alarm device to the second portable alarm device via a sub 1 GHz radio signal, thus allowing the wireless alarm activation signal to be received by a second portable alarm device or devices at a distance of up to 1 km from the first portable alarm device.

If the second portable alarm device is a mobile device such as a cellular telephone, computer tablet or smart-watch, communication between the first portable alarm device and the mobile device may be controlled by means of a mobile application software, also known as a mobile app, running on the mobile device. As is known in the art, a mobile application or mobile app is a computer program designed to run on a mobile device such as a cellular telephone, a computer tablet or a smart-watch.

If the second portable device is a mobile device having such a mobile application software installed, the alarm raised in the mobile device may comprise the mobile application software announcing the alarm vocally, and/or the mobile application software presenting the alarm as a pop-up massage on a graphical display of the mobile device.

Also, such a mobile application software may be used by an operator to control the first portable device, e.g. to turn the first portable device on or off, or to set the parameter threshold value or values.

Communication between the first portable alarm device and the second portable alarm device or devices, as the case may be, may be cloud-based, allowing the first and second portable alarm devices to communicate and exchange information via a central storage and information node, e.g. utilising the Internet Protocol (IP) communications protocol.

A barcode, e.g. a Universal Product Code (UPC) barcode or a Quick Response Code (QR) two-dimensional barcode, may be printed on the outside of the casing of the first portable alarm device. This will allow a third party to get into contact with the owner of the first portable alarm device by scanning the QR code or in addition, or alternatively, receive information on mobile devices connected to the first portable alarm device. This may be useful, for example, when the first portable alarm device is positioned inside an automobile to monitor temperature in the same. If the first portable alarm device is positioned visibly on the inside of a window of the automobile, and if an alarm is triggered in the first portable alarm device, third parties can quickly scan the QR code, contact the owner and inform him that the alarm has been triggered.

The barcode may in addition, or alternatively, contain information on activates or actions a third party may take if the alarm is triggered, e.g. to contact the owner, to contact emergency services or other appropriate actions. The barcode may for example contain a hypertext link to a web page where such activities or actions are stated. According to a third aspect of the invention, a device having the same functionality as the above-described portable alarm device may be installed permanently inside an apparatus, e.g. inside an electric charger, so that the device can monitor a physical parameter related to the operation of the apparatus, e.g. the inside temperature of the apparatus, and take appropriate action if a predefined threshold value of the parameter is exceeded, e.g. trigger an alarm in the device or cause a connected device to trigger an alarm, as previously described.

Above-discussed preferred and/or optional features of each aspect of the invention may be used, alone or in appropriate combination, in the other aspects of the invention. Description of the drawings

Following drawings are appended to facilitate the understanding of the invention:

Fig. 1 shows a portable alarm device according to one embodiment of the invention.

Figs. 2A to 2C show a portable alarm device according to another embodiment of the invention. Fig. 3 shows an alarm system according to one embodiment of the invention.

Fig. 4 shows a portable alarm device according to yet another embodiment of the invention.

It should be understood, however, that the drawings are not intended to limit the invention to the subject-matter depicted in the drawings. Detailed description of the invention

In the following, one or more specific embodiments of the invention will be described in more detail with reference to the drawings. However, it is specifically intended that the invention is not limited to the embodiments and illustrations contained herein, but includes modified forms of the embodiments including portions of the embodiments and combinations of elements of different embodiments as come within the scope of the following claims. It should be appreciated that in the development of any such actual implementation, as in any engineering or design project, numerous implementation-specific decisions must be made to achieve the developer's specific goals, such as compliance with system and/or business related constraints, which may vary from one implementation of the invention to another. Moreover, it should be appreciated that such a development effort might be complex and time consuming, but would nevertheless be a routine undertaking of design, fabrication and manufacture for the skilled person having the benefit of this disclosure.

It is appreciated that certain features of the invention, which, for clarity, have been described above in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the invention, which, for brevity, have been described in the context of a single embodiment, may also be provided separately or in any suitable sub-combination.

In particular, it will be appreciated that features described in relation to one particular embodiment may be interchangeable with features described in relation to the other embodiments.

Fig. 1 shows an embodiment of a portable alarm device 100 according to the invention.

The portable alarm device 100 comprises a casing or encapsulation 1 displaying a top surface la and a bottom surface lb. The portable alarm device further comprises a temperature sensor 2, a printed circuit board (PCB) on which is mounted a microcontroller 3, an audible alarm 4, one or a plurality of light diodes 5, one or a plurality of electric energy storage units 6, e.g. a button battery, a communication unit 7, and a fastener 9 allowing the portable alarm device to be attached to different surfaces, such as the back-side of a cellular telephone or a portable computer (pc), a window in an automobile or in a baby carriage, in an automobile, etc. The fastener 9 may comprise a heat resistant or thermally conductive double-sided tape or glue, a hook-and-loop fastener, and magnets.

When in use, the portable alarm device 100 is non-permanent ly fastened to the object whose temperature it is to monitor. Via the communication unit 7, the portable alarm device is in communication with a cellular telephone 10. When the temperature sensor 2 detects a temperature value the exceeds a preset or predefined temperature threshold value, the microcontroller 3 activates the audible alarm 4 and also instructs the communication unit 7 to transmit a wireless alarm activation signal to the cellular telephone 10. In response to receiving the wireless alarm activation signal, the cellular telephone activates a visual, tactile and/or audible alarm informing that the temperature of the monitored object has exceeded the preset or predefined temperature threshold value.

Said one or a plurality of energy storage units 6 may comprise one or a plurality of button batteries, e.g. lithium-ion batteries. The one or a plurality of energy storage units 6 may be chargeable energy storage units. For charging the energy storage unit or units 6, a solar cell film (not disclosed) may be arranged on the outside surface of the casing 1 , e.g. on the top surface la of the casing 1. If the portable alarm device is chargeable by external means, e.g. using an electric charger (not disclosed), the portable alarm device may comprise a charging port (not disclosed) for receiving a charging connector, e.g. in the form of a micro Universal Serial Bus (USB) connector. However, the energy storage unit or units 6, if chargeable, may alternatively be charged using wireless conductive charging means. Such conductive charging means are known in the art and will not be discussed further here.

The communication unit 7 may be a Bluetooth or Bluetooth Low Energy (BLE) unit. The audible alarm 4 may be a piezoelectric sounder. A piezoelectric sounder may provide sensible vibrations and may therefore also function as a tactile alarm in the portable alarm device.

A barcode 8, e.g. a Universal Product Code (UPC) barcode or a Quick Response Code (QR) two-dimensional barcode, may be printed on the outside of the casing 1 to provide information to third parties, as previously discussed.

Figs. 2A, 2B and 2C show a second embodiment of a portable alarm device 102 according to the invention. The portable alarm device 102 comprises a printed circuit board (PCB) 104 (see Fig. 2A), a microcontroller 106, a temperature sensor 108, an accelerometer 1 10, a light-emitting diode (LED) 1 12, an energy storage unit 1 16 and a tactile and audible alarm 1 18. The energy storage unit 1 16 and the tactile and audible alarm 1 18 are positioned on one side of the PCB 104 and the components making up the microcontroller 106, the temperature sensor 108, the accelerometer 1 10, the light-emitting diode (LED) 1 12 and the wireless communication module 1 14 are positioned on the other side of the PCB 104. The portable alarm device 102 may also comprise a wireless communication module 1 14 for communicating wirelessly with other devices in a way which will be discussed in more detail below with reference to Fig. 3.

The tactile and audible alarm 1 18 may be a piezoelectric sounder which, when activated, is configured to provide sensible vibrations and an audible sound. The energy storage unit 1 16 may be a disposable battery, e.g. a bottom type battery, e.g. a CR2032 battery. Alternatively, the energy storage unit may be a rechargeable battery of a type known in the art. The microcontroller 106 may be an ARM Cortex-M0 microcontroller.

The PCB 104 and the components mounted thereon are enclosed in a casing 120 displaying a top surface 120a and a bottom surface 120b.

On the top surface 120a, the portable alarm device displays an opening or a transparent section 122 in the casing allowing the LED 1 12 to be visible from outside of the casing 120. On the top surface 120a, there is an operable button 124 allowing an operator to control the portable alarm device 102, e.g. switching the portable alarm device 102 on and off, checking energy level in the energy storage unit 1 16 etc. The LED 1 12 may be configured to indicate the status of the device 102, e.g. to operate in heartbeat mode to indicate whether it is switched on or not.

On the bottom surface 120b, a fastener comprising magnets 126 are recessed in the casing 120 allowing the device 102 to be attached to a surface of an object it is to monitor, e.g. a cellular telephone, a lap-top computer or an electric charger. It is understood, however, that the fastener may be of any type suitable to non- permanently attach the device 102 to an object to be monitored, or to non- permanently position the device 102 in an environment to be monitored. For example, the fastener may comprise any one of a magnet, an adhesive tape or glue and a hook-and-loop fastener, i.e. Velcro-type fastener, or a combination thereof. The fastener may in addition, or alternatively, comprise a loop 130, e.g. as is disclosed in Fig. 4, allowing the portable alarm device to be suspended or positioned in place inside an automobile, a baby carriage or other confined location to monitor said at least one parameter, e.g. temperature, in that location.

The casing 120 may display at least one through-opening 128 allowing ambient air access into the casing 120. Advantageously, the tactile and audible alarm 1 18, if being a piezoelectric sounder, is positioned adjacent but at a distance, e.g. 1 to 4 mm, from the inside wall of the casing 120 so that a resonance cavity is formed between the piezoelectric sounder and the casing 120.

The physical dimensions of the portable alarm device 102 is approximately 50 mm by, 30 mm by 10 mm. Consequently, the dimensions of the device 102 makes it highly portable and allows it to be easily attached to different objects or positioned in different environments it is to monitor.

In operation, the device 102 is attached to an object or positioned in an environment it is to monitor. Using the temperature sensor 108 and/or the accelerometer 1 10, the microcontroller 106 monitors the temperature and/or the motion of the monitored object or environment. If the temperature and/or the motion exceeds a preset or predefined threshold value, e.g. a preset or predefined temperature and/or a preset or predefined acceleration, the microcontroller 106 triggers a tactile and audible alarm by activating the tactile and audible alarm 1 18. Also, or alternatively, the microcontroller 106 may trigger a visible alarm by activating the LED 1 12, e.g. by bringing the LED to blink with a frequency indicating an alarm situation. Activation of the visible, tactile and/or audible alarm will alert persons in the vicinity of the portable alarm device 102 that the preset or predefined temperature and/or preset or predefined acceleration of the monitored object or environment.

In addition to activating the visible, tactile and/or audible alarm in the device 102, the microcontroller 106 may be configured to transmit an alarm activation signal to one or a plurality of second portable alarm devices. This is illustrated in Fig. 3, which shows an alarm system 200 according to one embodiment of the invention.

The system 200 comprises a first portable alarm device 202 configured to monitor at least one physical parameter of an object or in an environment. The first portable alarm device 202 may be configured to activate a visible, tactile and/or audible alarm in the device 202 when the at least one physical parameter exceeds a preset or predefined threshold value. The first portable alarm device 202 may for example comprise the same components and operate in the same way as any one of the previously discussed portable alarm devices 100 and 102, and the at least one physical parameter may be temperature and/or acceleration. The first portable alarm device 202 may for example be positioned in an automobile to monitor the temperature inside the automobile, or in a baby carriage to monitor the temperature inside the carriage and/or movement of the carriage.

The system further comprises one or a plurality of second portable alarm devices 204, 204'. The second portable alarm devices may be similar to the first portable alarm device 202, but need not have means for monitoring a physical parameter. For example, the second portable alarm device 204 may have the same components as the previously discussed device 102, except for the temperature sensor 108 and the accelerometer 1 10. The second portable alarm device 204 should, however, have at least one of a visible, tactile and audible alarm. When the first device 202 detects that the monitored parameter or parameters exceed their respective preset or predefined threshold value, the first device 202 may, in addition or as an alternative to activating a visible, tactile and/or audible alarm in the device 202 itself, transmit a wireless alarm activation signal 206 to one or a plurality of the second portable alarm devices 204, 204', in response to which signal 206 the second portable alarm devices 204, 204' activates a visible, tactile and/or audible alarm.

The wireless alarm activation signal 206 may be realised using any communication system or communication standard known in the art, e.g. Wi-fi, Bluetooth, Bluetooth Low Energy (BLE), radio signals, or the mobile phone network. However, it may be advantageous if the signal 206 is a sub 1 GHz signal, thus allowing the wireless alarm activation signal 206 to be received by second portable alarm devices 204, 204' at a distance of up to 1 km from the first portable alarm device 202.

According to one embodiment of the system 200, the second portable alarm device is a cellular telephone 204'. In this embodiment, the received alarm activation signal 206 may cause a mobile application software installed in the cellular telephone 204' to announce the alarm vocally, and/or to present the alarm as a pop-up massage on a graphical display of the cellular telephone 204'.

According to one embodiment of the system 200, the alarm activation signal 206 may be relayed between the second portable alarm devices 204. For example, as is disclosed in Fig. 4, a cellular telephone acting as a second portable alarm device 204' may receive a relayed alarm activation signal 206' from one of the other second alarm devices 204 in the system 200. In such a configuration, the relayed alarm activation signal 206' may advantageously utilise the Bluetooth communication standard, or another short-range communication standard.

According to one embodiment of the system 200, the second portable alarm devices 204, 204' may be configured to transmit wireless signals to the first portable alarm device 202, either directly, as is indicated by signals 208 in Fig. 4 or relayed via other second portable alarm devices 204 in the system, as is indicated by signal 208'. Such signals may be used by an operator to control the first portable alarm device, e.g. to start or shut down the device 202, or to set the preset or predefined threshold value or values of the monitored parameters.

In the preceding description, various aspects of the apparatus according to the invention have been described with reference to the illustrative embodiments. For purposes of explanation, specific numbers, systems and configurations were set forth in order to provide a thorough understanding of the apparatus and its workings. However, this description is not intended to be construed in a limiting sense. Various modifications and variations of the illustrative embodiment, as well as other embodiments of the apparatus, which are apparent to person skilled in the art to which the disclosed subject-matter pertains, are deemed to lie within the scope of the present invention as defined by the following claims.

Claims

1. A portable alarm device (100, 102, 202) configured to monitor at least one physical parameter of an object or in an environment, characterised in that the portable alarm device (100, 102, 202) comprises:

- a disposable or chargeable electric energy storage unit (1 16);

- at least one sensor (106, 108) configured to monitor said at least one parameter;

- at least one alarm (1 12, 1 18);

- a microcontroller (106) configured to activate said at least one alarm (1 12, 1 18) if the at least one sensor (106, 108) detects a value of said at least one parameter that exceeds a preset parameter threshold value;

- a casing (120) enclosing the at least one sensor (106, 108), the at least one alarm (1 12, 1 18) and the microcontroller (106); and

- a fastener (126) for non-permanently attaching the casing (120) to or positioning the casing (120) in an environment in which said at least one parameter is to be monitored.

2. The portable alarm device (100, 102, 202) according to claim 1 , wherein the at least one parameter comprises temperature and wherein said at least one sensor comprises a temperature sensor.

3. The portable alarm device (100, 102, 202) according to any one of the preceding claims, wherein the fastener (126) comprises at least one of a magnet, an adhesive tape or glue and a hook-and-loop fastener.

4. The portable alarm device (100, 102, 202) according to any one of the preceding claims, wherein said at least one sensor comprises a temperature sensor (108), and wherein the fastener (126) is thermally conductive.

5. The portable device according to any one of the preceding claims, wherein the casing (120) displays at least one through-opening (128) allowing ambient air access into the casing (120).

6. The portable device according to any one of the preceding claims, wherein said alarm is at least one of a visible alarm (1 12), a tactile alarm (1 18) and an audible alarm (1 18).

7. The portable device according to claim 6, wherein said tactile alarm (1 18) and/or said audible alarm (1 18) is a piezoelectric sounder.

8. The portable device according to any one of the preceding claims, wherein the portable device comprises:

- a communication module (1 14) configured to transmit a wireless alarm signal (206) when the at least one sensor (106, 108) detects a value of said at least one parameter that exceeds a preset parameter threshold value.

9. An alarm system (200) comprising a first portable alarm device (202) according to claim 8 and a second portable alarm device (204, 204') configured to receive the wireless alarm activation signal (206) from the first portable alarm device (202) and, in response to the received wireless alarm activation signal (206), activate a visible, tactile and/or audible alarm in the second portable alarm device (204, 204').

10. The system (200) according to claim 9, wherein the wireless alarm activation signal (206) is transmitted from the first portable alarm device (202) to the second portable alarm device (204) via a sub 1 GHz radio signal.

1 1. The system (200) according to claim 9 or 10, wherein the system (200) comprises a plurality of second portable alarm devices (204, 204'), and wherein the wireless alarm activation signal (206) is transmitted from the first portable alarm device (202) to one of said plurality of second portable alarm devices (204') via a another of said plurality of second portable alarm devices (204).

12. The system (200) according to any one of claims 9-1 1 , wherein said second portable alarm device or devices comprise(s) a cellular telephone (204').