Abstract: A furnace filter indicator system comprises a pressure differential switch that monitors air pressure near a furnace filter, and a transmitter coupled to the pressure differential switch sends a signal to a receiver within a thermostat. The receiver includes an indicator for indicating the status of the furnace filter. If the pressure differential near the furnace filter triggers the switch, then the indicator will receive a “dirty” signal and will indicate that the furnace filter is dirty and should be replaced. The furnace filter indicator system is able to be installed on a previously installed furnace/thermostat system by utilizing the pre-existing wiring.

Abstract: A device for detecting a hematoma or subcutaneous hemorrhage after a PCI, which includes a bandage provided with fastening elements for its placement at the PCI access site, and the use of a safety bandage for producing the same. In the device, the bandage includes a flexible and, in its longitudinal direction, non-elastic element connected to a strain sensor so arranged that the strain sensor, when the element after the placement of the bandage at the access site is subjected to a change in tension as a result of a hematoma or subcutaneous hemorrhage after the PCI, emits a signal that is indicative of the hematoma or hemorrhage.

Abstract: A method and device for dual-channel transmission of safety-relevant sensor signals. In the method, two sensor signals to be monitored are generated parallel to one another by two sensors and the generated sensor signals are transmitted to a common evaluation unit via two separate, input-side transmission channels. Within the evaluation unit, the permissibility of the transmitted sensor signals is checked using prescribed calculation specifications that correspond to one another and an evaluation unit output signal representing permissibility or impermissibility is generated for each sensor signal. The individual processing steps of the two calculation specifications are decoupled by the evaluation unit for the two sensor signals and performed diversified within the evaluation unit. The generated output signals are output via two separate, output-side transmission channels.

Abstract: A pressure indicator for a motor vehicle (or other) fuel tank, that will indicate when pressure at the cap/container interface or vapor pressure in the tank drops below a predetermined level, which will normally mean that the fuel cap is not tightly secured to the tank's opening. The cap/container interface or vapor pressure will be detected by sensors in a rubber gasket (either in the cap or in the tank's opening that the cap fits over) or in a washer for the fuel cap. When the sensors detect a pressure below the predetermined level, BLUE TOOTH (or other appropriate) technology will be used to send a signal to a receiver (preferably in a key ring attachment) that will cause a red light to flash (or other appropriate visual, audio or tactile notice). The light may also flash when the cap is temporarily removed for refueling.

Abstract: A system for preventing accidents in the operation of a monitored apparatus carried by a user has terminal in direct contact with the body of the user and provided with a circuit for continuously or periodically transmitting an authorizing user data signal through the body of the user. A signal receiver assigned on the monitored apparatus or machine has an interface in contact with the user for receiving the signal, a circuit for continuously or periodically testing the received data signal, another circuit for outputting a clearance signal that allows operation of the monitored machine or apparatus after a successful test of the received authorizing user data signal, and yet another circuit for terminating output of the clearance signal following a successful test of the authorizing user data signal when a subsequent test of the data signal fails.

Abstract: A system and a method for determining positions of structures on a substrate are disclosed. The system includes at least one measurement table (20) movable in the X-coordinate direction and in the Y-coordinate direction, a measurement objective (9) and a camera for determining the positions of the structures (3) on the substrate (2). The position of the measurement objective (9) and/or the measurement table (20) may be determined by at least one interferometer (24). The system is surrounded by a housing representing a climatic chamber (50) provided with an active pressure regulation.

Abstract: A therapeutic mattress is provided having a base layer, a plurality of separate air cell sections, an air source and a valve. The separate air cell sections have a plurality of fluidly interconnected air cell members extending vertically from a bottom wall. The air cell members of the air cell sections are independently moveable in a plurality of directions. The valve is fluidly connected to the plurality of separate air cell sections. The air source is connected to the valve to independently increase the air pressure in the air cell sections to a desired air pressure.

Abstract: Through the use of an electro-acoustic transducer, a pressure wave of at least a predetermined intensity may be detected, such as one that may occur upon the activation of a vehicle's air bag. As the electro-acoustic transducer has a diaphragm that can be displaced under the influence of a pressure wave, the transducer can therefore be monitored for an event occurrence indicative of the pressure wave. This monitoring may involve passively monitoring an electrical connection of the transducer for an electrical signal of a predetermined level, such that the electrical signal is the event indicative of the pressure wave. The monitoring may involve passively monitoring a pressure switch, such that activation of the pressure switch is the event indicative of the pressure wave. Upon detection of the pressure wave event, a trigger signal may be output to an emergency notification device to instigate a communication regarding a possible emergency situation.

Abstract: A high integrity protection system (HIPS) for protection of a gathering line downstream of a number of wellhead flow lines includes: an inlet; an outlet; two sets of two series-connected isolation valves (ZVs) in fluid communication with the inlet and outlet, the two sets being in parallel fluid flow relation to each other, either one or both of the sets of ZVs operable as a path for fluid entering the inlet and passing through the outlet to the downstream pipe; two vent control valves (VCVs), each connected to piping intermediate one set of series-connected ZVs, the VCVs being in fluid communication with a vent line, whereby, upon opening of a VCV, process pressure between the two ZVs is vented; a signal-generating safety logic solver, in accordance with preprogrammed safety and operational protocols; and pressure sensing transmitters attached to piping upstream of the HIPS outlet. The system allows full-stroke, tight shut-off testing of the ZVs without interruption of wellhead production.

Abstract: A visual indicating device for mounting on a hose includes a body having an outer wall and defining a central passage extending axially through the body between a first end and a second end, and a plurality of lights arranged around the annular body so as to be visible from beyond the outer wall. A power source is arranged within the annular body, and a switch selectively energizes the plurality of lights from the power source. The visual indicating device includes groups of differing colored lights. Mounted on a hose, one of the groups indicates the general direction of the nozzle and another of the groups indicates the general direction of an exit. The switch automatically energizes the lights upon pressurization of the hose.

Abstract: Systems and methods for monitoring operation of a pump, including verifying operation or actions of a pump, are disclosed. A baseline profile for one or more parameters of a pump may be established. An operating profile may then be created by recording one or more values for the same set of parameters during subsequent operation of the pump. The values of the baseline profile and the operating profile may then be compared at one or more points or sets of points. If the operating profile differs from the baseline profile by more than a certain tolerance an alarm may be sent or another action taken, for example the pumping system may shut down, etc.

Abstract: An apparatus designed to alert on an abnormal condition inside of a fiber bundle (116). The apparatus includes an air pipe (112) configured inside of the fiber bundle, an air compression element adapted to apply air into the air pipe, at least one sensor (124, 128, 132, 136, 148) configured in combination with the air pipe wherein at least one sensor is coupled to at least one location on the air pipe. An alerting element (172, 308) is configured to notify on an abnormal measurements of at least one sensor.

Abstract: A control system of a patient support surface calculates a surface performance index as a function of pressure and shear. The control system also receives information from an electronic medical record (EMR) corresponding to a person's susceptibility of developing at least one of a pressure ulcer and a superficial lesion and adjusts at least one of a component and a characteristic of the person support surface based on the information.

Abstract: A method and apparatus is disclosed for determining pressure provided by a pump element of a topical negative pressure (TNP) system. The method includes the steps of determining a current pressure provided by a pump element of a TNP system, comparing the determined pressure with a predetermined pressure and selecting a target pressure intermediate the current and predetermined pressure and increasing or decreasing pump speed to respectively increase or decrease pressure until the current pressure matches the target pressure.

Abstract: An apparatus for remote inspection of fire extinguishers at one or a system of fire extinguisher stations includes, e.g., at each fire extinguisher station: a detector for lack of presence of a fire extinguisher in its installed position at the fire extinguisher station; a detector for out-of-range pressure of contents of the fire extinguisher at the fire extinguisher station; a detector for an obstruction to viewing of or access to the fire extinguisher at the fire extinguisher station; and a device for transmission of inspection report information from the fire extinguisher station to a remote central station.

Abstract: A fluid detection system comprises a liquid sensor, an air pump and an atmospheric pressure sensor encased within an air and water permeable casing defining an enclosed air space. The pressure sensor acquires pressure samples within the casing, the air pump expelling additional gas into the casing. In response to determining a flood-status or a non-flood-status state of the fluid detection system and comparing the samples, a failure of the fluid detection system or an immersion of the fluid detection system in fluid is determined. In some embodiments, failure is determined if a second sample is greater than a first sample in a non-flooded state, and in others immersion is determined if a second sample is greater than a first sample value and the determined state is flooded. In some examples, gas is expelled across a liquid detection surface and a third sample value is acquired.

Abstract: This invention is a water consumption monitoring and control system comprised of a base unit, itself comprising a display and a data entry device, a microprocessor, a communication link to water meters, pressure sensors, temperature sensors, flush toilet vibration sensors and shut-off valves. In addition the base unit has access to the Internet and can access a server which holds a database of water conservation information. This database includes watering advisories from the local government, and weather information from the weather office. The server runs an algorithm and generates control data which is sent to the base unit.

Abstract: The present invention relates to detection and alarm systems for predicting and detecting the location of spills, leaks, emissions, and/or pollution sources, i.e., unwanted fluid (liquid/gas) flow/escape, at refineries, e.g., oil and gas refineries, and plants, e.g., petrochemical, chemical, pharmaceutical, and food processing plants, and avoiding said unwanted flow/escape. According to one embodiment, said system comprises at least one detector, at least one battery powered radio frequency transmitter, preferably, according to one embodiment, a 900 megahertz spread spectrum transmitter, and a central processing location which, according to one embodiment, is preferably capable of handling up to 3000 points in a single cell site.

Abstract: A determination of bleed valve activation in a gas turbine engine can be difficult unless the engine is maintained at a steady idle state for comparison between that state and effects of activation of the bleed valve. Furthermore, specific test activation of bleed valves increases wear and tear on those valves. By sensing a flow pressure response signal and then through appropriate averaging and processing through a non-linear filter, it is possible to identify bleed valve activation by a target signal response exceeding a threshold indicative of such bleed valve activation.

Abstract: A pressure sensing device for an electronic device includes a pressure sensing unit, a control unit, and an alarm unit. The pressure sensing unit is installed in the electronic device, and used for detecting fluid pressure to generate a pressure signal. The control unit is coupled to the pressure sensing unit, and used for determining variation in the fluid pressure in the electronic device according to the pressure signal and generating a control signal. The alarm unit is coupled to the control unit, and used for outputting an alarm signal according to the control signal to execute an alarm function.

Abstract: A monitoring system for monitoring an air-conditioner may include a pressure sensor for detecting the pressure of the fluid of the air-conditioner, a power sensor for detecting the presence of supply voltage supplied to the air-conditioner and applied voltage which is applied to the air-conditioner, an activation device to activate an alarm based upon the detection of the pressure from the pressure sensor, the detection of the supply voltage to the air-conditioner and the detection of the applied voltage to the air-conditioner. The activation device may be activated based only on the loss of pressure detected by the pressure sensor, and the activation device may not be activated if the supplied voltage is detected. The activation device may be activated when both the supplied voltage is detected and the applied voltage is not detected, and the activation device may be connected to a disconnect switch to detect the supplied voltage.

Abstract: A comparative pressure monitoring instrument (10) houses a switch (14) having first and second ports (18) and (20), and a high flow impedance 16. The ports (18) and (20) are in fluidal communication with a first pressure source (72) and a second pressure source (82) respectively. The impedance (16) is coupled (i.e. shunted) across the switch ports (18) and (20) and the first and second pressure sources (72, 82). The switch (14) switches between a first state characterised by a pressure differential across the impedance (16) being less than a preset level and a second state characterised by the pressure differential across the impedance (16) being equal to or greater than the preset difference. Any difference in pressure between the sources (72) and (82) will cause an air/gas flow through the impedance (16) and thus a pressure drop across the impedance (16).

Abstract: A syringe for performing a medical procedure includes a pressure sensor, a volume sensor, and a compensation circuit. The volume sensor measures a volume of a flowable material that is dispensed from the syringe, the pressure sensor measures a pressure being applied to the flowable material, and the compensation circuit calculates a delivered volume of the flowable material by accounting for system compliance (expansion) as the pressure is increased. By compensating for system compliance in this manner, a syringe can be used in high pressure procedures while still providing accurately controllable material delivery.

Abstract: An air pressure sensor (2) for a vehicle tire warning system includes a tubular housing (21) defining a chamber (218), an air pressure actuating device seated in the chamber and being moveable back and forth in the chamber in response to air pressure change in the vehicle tire, and a switch device to electrically connect a high air pressure warning circuit or a low air pressure warning circuit under the drive of the air pressure actuating device. The chamber of the tubular housing is communicated to the atmosphere via a connecting pipe (29).

Abstract: A system and method for adjusting insulin infusion volume based on air in an infusion set tube includes inputting at least one location and length of an air bubble along the infusion set tube. An air bubble volume is determined in the infusion set tube. An insulin infusion volume is determined based on a desired insulin infusion. A determination is then made whether the desired insulin infusion would include the air bubble volume based on the inputted location and length of the air bubble. The air bubble volume is added to the insulin infusion volume to make an adjusted insulin infusion volume if the insulin infusion volume includes the air bubble.

Abstract: The invention relates to a method for monitoring the gas tightness of a cooling system for a refrigerated vehicle comprising the following steps: recording of a chronological temperature sequence at least at a first point in the cooling system and the determination of any change in the temperature at the first point within a first time interval and comparison of the change with a first reference value and the triggering of a first warning signal in the event that the change exceeds the first reference value; and/or subjecting a line section of the cooling system to a positive pressure and blocking this line section and recording a chronological pressure sequence at least at a first point in the line section and the determination of any change in the pressure in the second point within a second time interval and comparison of the change with a second reference value and the triggering of a second warning signal in the event that the change exceeds the second reference value.

Abstract: A selectable mode field transmitter is configurable to operate in one of a plurality of operating modes having different combinations of function, performance, and power consumption. The selectable mode field transmitter includes a housing, a sensor located within the housing, and transmitter circuitry for transmitting data provided by the sensor to a receiver external to the housing. The transmitter circuitry includes a controller that electrically configures the transmitter circuitry to one of a plurality of operational modes in response to mode selection data received from a source external to the housing. Therefore, the selectable mode field transmitter can be configured based on the needs or requirements of a particular application.

Abstract: A device for detecting a collision of a vehicle with an obstacle includes an enclosed space positioned behind a front bumper cover. Deformation or displacement of the bumper cover due to a collision is transmitted to the enclosed space. Air pressure in the enclosed space and its temperature are measured by sensors and electrical signals representing the pressure and the temperature are fed to an electronic control unit that determines whether the enclosed space is hermetically closed or not based on the pressure and the temperature of the air in the enclosed space. If the enclosed space becomes non-hermetical due to a collision impact, the air therein leaks and the pressure therein becomes atmospheric pressure irrespective of the temperature of the air in the enclosed space. Therefore, the hermetical condition of the enclosed space is surely detected.

Abstract: A filter monitoring device which detects variances in pressure of fluid flowing through a filter element in a filter assembly includes (1) an indicator for conveying data of changes in the differential pressure of the fluid in the filter assembly and (2) a temperature sensor for transmitting data showing any changes in temperature of the fluid being filtered. A microcontroller converts data received about changes in differential pressure and temperature sensing means to digital format and transmits the data along two differential digital lines to a driver and output connector.

Abstract: A signal representative of a pressure is received from an industrial transmitter. An isolation indicator signal may be obtained by control signals from an isolation valve assembly or by signals from a DCS to indicate that isolation has occurred.

Abstract: An improved flow meter, which has diagnostic capabilities due to the reading of total pressure head loss, calculation of corresponding flow rate and comparison with flow rates calculated from other differential pressures.

Abstract: This invention relates to a water condition indication system for a swimming pool comprising a water condition sensor (110), a memory (130) and a processor (140) and alarm (150). The memory collects and stores the information. The data processor filters the water condition information, corrects for perturbations, and generates an alarm when a body fall into a pool causes a change in the water condition that exceeds a predetermined body entrance criterion. Analysis of the output of one or more filters reduces the occurrence of false alarms while still providing a substantially rapid response time under the prevailing conditions.

Abstract: A sampling system for quantifying the amount of contaminants in a controlled environment within a facility. The system has an air sampling devices each associated with a respective flow switch module, both within the controlled environment, and a first and second controller located outside the controlled environment. The first controller is in flow communication with the air sampling devices. The first controller is also in flow communication with the flow switch modules and controls a vacuum source to draw a predetermined volume of air through the at least one air sampling device via the at least one flow switch module at a desired flow rate. The flow switch module detects when the actual flow rate falls below or above a predetermined value, and generates an alarm.

Abstract: The invention relates to a method and system in connection with a wristop diving computer (1). According to the method, at least the pressure of a gas bottle (2) is measured and the pressure data is transmitted under water using a low first frequency f1 to a wristop computer (1). According to the invention, on the surface of the water a second frequency f2, higher than the first frequency f1, is used for two-way telecommunications between the gas bottle (2) and the wristop computer (1).

Abstract: Diagnostic and response systems and methods for a fluid power system acquire data from pressure and temperature sensors disposed in the fluid power system, analyze the data in a failure algorithm to build a history of cumulative damage to hoses in the fluid power system, communicates an indication of potential imminent hose failure to a central location when a level of the cumulative damage indicates imminent failure of a hose, analyze the information at the central location to determine an appropriate response, and transmit information about the fluid power system, including location, and identification of the hose about to fail to a response unit. The response unit responds to the location and replaces the component prior to failure, or the communication might include information that the hose has failed, such that the response unit replaces the failed hose to return the fluid power system to normal operation.

Abstract: A cost effective method is provided for determining empty and/or near empty medical and other medical emergency oxygen tanks employing a single, simple device for practicing the method, comprised of 5 or 6 readily obtainable components, to issue visual and audible alarms when the oxygen pressure of a medical oxygen tank has decreased to a predetermined pressure, deemed too low to provide the needed and/or prescribed oxygen flow rate to a patient to alert medical personnel and other caregivers that it is time to replace the tank in with a full tank.

Abstract: A measuring device is disclosed for capacitive pressure and/or temperature measurement, particularly for tire pressure control systems, having at least one sensor, which has a capacitive measuring element to detect a state value, which is applied at an output-side measuring node of the measuring element, with at least one A/D converter operating according to the dual-slope method, with a charging/discharging circuit, for mutual charging and discharging of the measuring element and for generating a sawtooth-shaped measuring potential at the measuring node as a measure for the capacitance of the measuring element, with a period counter, which determines the periods of the measuring potential, and with a clock counter, which determines the cycles of a clock signal, which lie within the duration of at least one period of the measuring potential. The invention relates to a measuring method for capacitive pressure and/or temperature measurement.

Abstract: A method, computer program product, and infusion pump assembly for determining a first rate-of-change force reading that corresponds to the delivery of a first dose of an infusible fluid via an infusion pump assembly. At least a second rate-of-change force reading is determined that corresponds to the delivery of at least a second dose of the infusible fluid via the infusion pump assembly. An average rate-of-change force reading is determined based, at least in part upon the first rate-of-change force reading and the at least a second rate-of-change force reading.

Abstract: An apparatus, system and method for monitoring and reporting the tethered/untethered status of a mobile asset are described. An asset tracking device comprises a sensor and circuit that detects whether a physical connection exists between a tractor portion and a trailer portion of a tractor/trailer vehicle. The physical connection is detected through the connection of an air hose coupling (or glad hand) at the trailer front wall. The sensor is continuously monitored by the sensor circuit and when a change is detected, the circuit sends a signal that turns on the power to the rest of the system. This enables the system to run in a very low power mode for extended periods of time. The sensor, which is located on the air hose (glad hand) coupling, senses the presence (or non-presence) of a tractor attached to the trailer and sends a trigger signal to turn on the power to the rest of the system, enabling the system to operate for extended periods of time on battery power.

Abstract: A warning device for a gas cylinder, it is provided on a gas pressure gauge at least with a dial, a needle pointer and a pointer switch; the pressure gauge is connected to an electric power supply and a warning unit; when the amount of the combustion gas is reduced, the needle pointer activates the pointer switch to turn on the warning unit, thus the warning unit emits a warning to remind a user to change the gas cylinder because of exhaustion of combustion gas, thus the bothersome work of inspecting the remaining gas amount by looking at a gas pressure gauge time after time can be saved, and an effect of convenience of using can be provided.

Abstract: A device for identifying the air flow condition within a clothes dryer having a lint filter, an exhaust passage, and a blower is disclosed. The device includes a sensor, an input having a first end connected to the sensor and a free second end, wherein the free second end is adapted to be disposed within the clothes dryer, upstream from a filter, and wherein the sensor detects a differential between an operating pressure at the free second end of input versus a reference pressure to thereby determine whether a sufficient vacuum is present within the clothes dryer, and an output that provides an output characteristic based on the differential, wherein the output characteristic changes from a first characteristic to a second characteristic when the differential surpasses a differential threshold.

Abstract: In a pressure switch, a joint coupling holder is mounted via an opening in a case constituting a housing. A plurality of engagement pawls that make up the joint coupling holder engages with a bottom of the case. Further, by inserting a cap into a recess of the joint coupling holder, the engaged state of the engagement pawls is maintained, whereby the housing, which is made from a resin material, and the joint coupling holder are strongly and rigidly connected together.

Abstract: A SIS-SCS for a fluid transfer facility has a connective interface providing signal connectivity to overfill and ground circuitry in individual fill lanes, to pump and valve control circuitry, and to individual ones of input mechanisms, and executable software routines for monitoring input at the connective interface, and for providing output signals through the connective interface to external devices and equipment including at least the pump and valve control circuitry, the input mechanisms for input of fill parameters, and to the one or both of overfill and ground monitoring circuits.

Abstract: A process pulsation diagnostic system comprises a primary element, a sensor and a processor. The primary element generates a differential pressure along a fluid flow. The sensor samples the differential pressure. The processor generates a pulsation diagnostic based on a standard deviation of the differential pressure, such that the pulsation diagnostic is indicative of a degree of process pulsation in the fluid flow.

Abstract: A rebreather safety monitoring device comprising a carbon dioxide sensor provided with a gas sampler adapted for sampling a gas in a rebreather breathing loop from a location between an inhale one-way valve on a rebreather mouthpiece and a carbon dioxide scrubber and providing the obtained gas sample to the carbon dioxide sensor, and a means to provide alarms or warnings based on the level of the expired carbon dioxide. The present invention detects a wide range of failures of a rebreather by measurement of the expired carbon dioxide level and application of that level to trigger alarms, provide loop shut-off or provide safety warnings.

Abstract: A fasten device for tire pressure alarm transmitter, which comprises a fasten base for fastening a valve core style transmitter, and a strip for binding the fasten base on wheel rim, wherein: the fasten base has a board shaped support portion, and a hole for accepting the strip to drill through is set on the support portion; a securing board is set on the middle portion of the support portion, and a position slot that matches with the valve core of the transmitter is excavated on the securing board; and a buckle that matches with the securing board is set on one end of the support portion to fasten the transmitter corporately. As the fasten base having a support portion, a buckle and a securing board with position slot are provided on the support portion.

Abstract: In one embodiment, a device comprises a container having a dispensing portion, a contents under pressure within the container, and an integrated circuit (IC) sensor device comprising a pressure sensor in communication with the contents under pressure. In various embodiments, the device can further comprise a fire extinguisher, a diving tank, a diving cylinder, a scuba tank, and an oxygen tank. Other embodiments of the invention relate to methods of monitoring, pressure sensing systems, and sensor and sensing modules.

Abstract: A monitoring system for monitoring an air-conditioner may include a pressure sensor for detecting the pressure of the fluid of the air-conditioner, a power sensor for detecting the presence of supply voltage supplied to the air-conditioner and applied voltage which is applied to the air-conditioner, an activation device to activate an alarm based upon the detection of the pressure from the pressure sensor, the detection of the supply voltage to the air-conditioner and the detection of the applied voltage to the air-conditioner. The activation device may be activated based only on the loss of pressure detected by the pressure sensor, and the activation device may not be activated if the supplied voltage is detected. The activation device may be activated when both the supplied voltage is detected and the applied voltage is not detected, and the activation device may be connected to a disconnect switch to detect the supplied voltage.

Abstract: An air cushion control system having an air chamber sensor including an air chamber, a bottom out sensor and an overinflation sensor, an air pump to inflate the air chamber, an air valve to release air from the air chamber, connections for the air cushion control system to an air cushion, and a microprocessor to control the inflation and the release of air from the air chamber. The air cushion control system reduces decubitus ulcers by incorporating both an automatic adjustment system to prevent the seated individual from bottoming-out in the air cushion and measure immersion depth to maximize pressure reduction.

Abstract: A device for detection of and warning against tsunamis. The device is characterized in that it includes a stationary base unit (2) and at least one courier (6) disengagably connected to the base unit (2), elements (3, 4, 5) for detection of the fulfillment of a predetermined condition, and elements (15) for releasing the courier from the base unit when the condition is fulfilled, the courier (6) including elements (10, 11, 12) in order to communicate to an external receiver that it is released from the base unit (2). A method for detection of and warning against tsunamis is also disclosed.