Abstract: A system which allows the firefighter to monitor a variety of safety related parameters during firefighting activities through audible and/or visual means. The system of the present invention monitors the pressure in the firefighter's breathing system and also monitors ambient temperature and motion of the firefighter. An audible alarm is activated to indicate a potential emergency situation relating to low remaining air time, impending thermal breakthrough or lack of motion of the firefighter.

Abstract: A SCUBA air diver computer having an analog gauge with an IR switch mounted thereon which is actuated by a mirror attached to the pointer of the gauge to indicate a preselected pressure reading and actuate an aural alarm.

Abstract: A vacuum adsorbing apparatus of a semiconductor fabrication facility is characterized by the incorporation of a digital vacuum sensor into the vacuum line for sensing the mounting state of a wafer or reticle on a mounting plate (adhered to or released by) by way of sensing the pressure existing in the vacuum line. The digital sensor reliably determines the state of the wafer or the reticle relative to the mounting plate. The mounting plate can thus be prevented from being transferred when the vacuum in the mounting plate is insufficient to adhere the wafer or reticle firmly to the plate. The wafer or the reticle can thus be prevented from being damaged or broken during its transfer.

Abstract: The present invention relates to an intelligent personal underwater monitng system which recognizes when a swimmer is in trouble and transmits a warning signal. The system comprises a device worn by the swimmer which senses water pressure and transmits a first signal when a predetermined depth is passed by the swimmer. The system further comprises a device for receiving the signals generated by the device worn by the swimmer and a neural network processor for processing the signals and generating an output signal representative of whether the swimmer is in trouble and an alarm signal generation device.

Abstract: The instant invention consists of an inner cannula of hosing amenable to transport of a liquid coupled with an outer cannula of hosing amenable to transport of a gas. As respects one embodiment, affixed to outer walling of the inner cannula and to inner walling of the outer cannula are rigid struts, typically three or four, at 120.degree. or right angles with respect to one another at various points along the respective lengths of the cannulae that serve to maintain separation of the cannulae from one another at times when the inner cannula is filled with a liquid and the outer cannula is filled with a gas under pressure. A second embodiment is strut free. Each cannula has an ingress end whereat a liquid is introduced into the inner cannula and whereat a gas is introduced into the outer cannula.

Abstract: A warning device configured for removable mounting in combination with a high pressure gas cylinder and a regulator used to regulate the high pressure gas supplied by the cylinder. The device compression mounts between the regulator and tank outlet on conventional portable oxygen and gas supply systems using a specially configured manifold. The device features one or a combination of alarms, from a group including audio, visual, electronic, and remotely transmitted alarms. These alarms are activated by a pressure switch monitoring the remaining supply in the gas cylinder through a conduit the manifold. The alarm signal from the device alerts the user, or a third party monitoring the user, of current tank pressure or will sound an alarm when remaining high pressure gas inside the gas cylinder drops below a predetermined level.

Abstract: An apparatus for monitoring tire pressure on automobiles, having an arrangement (1), intended for installation into a wheel, made up of a pressure sensor, a transmitter, and a circuit for operating the pressure sensor and transmitter, and having a battery (2) which supplies the circuit with power via a power supply line (3), the arrangement (1) and the battery (2) being located in a sealed housing (9). Located in the power supply line (3) is an electronic switch (4) which has a control electrode (5) and is nonconductive when the control electrode (5) is connected to ground.

Abstract: A method for fluid pressure analytical electronic heat and fire detection, and a corresponding heat detector, used for detecting heat and fire, having no moving component, such as a valve, switch, membrane, diaphragm, or similar actuatable device of moving parts, for effecting activation of a warning or alarm signal indicating a condition of excessive heat or fire. The analytical electronic heat detection mechanism is based on electronic circuitry including at least one fluid pressure transducer, logic, and other cooperatively functioning electronic components, for highly accurately and reproducibly, first analyzing a potential condition, and then logically determining, an actual condition of excessive heat or fire. The electronic heat detection mechanism is fully functional, by having at least one fluid chamber closed to any external source of fluid pressure. The invention includes an automatic electronic testing procedure for naturally stimulating the heat detection mechanism for effecting operation.

Abstract: The invention provides a method and device for detecting the state of an air filter in a ventilation system of the passenger compartment of an automobile vehicle. The installation is put into operation in a given mode and a parameter of an air flow emitted into the passenger compartment by an air nozzle of the installation is measured by means of a measurement device filled with a collector. The measured value of the parameter is then compared with a reference value, to determine whether or not the filter needs to be replaced.

Abstract: A dispensing monitor used in a SOG machine to planarize a semiconductor substrate which includes: a container, a gas control valve. a gas release valve, a pressure monitor, and a pressure sensing apparatus. A chemical solution contained in the container is controlled and conveyed through the gas control valve to be sprayed onto the substrate. The pressure monitor and the pressure sensing apparatus and the gas release valve are used for monitoring the internal pressure to keep a constant pressure so that the chemical solution is precisely exported.

Abstract: A pump failure alarm system which is provided in a hydraulic working machine comprising hydraulic pumps driven by a prime mover, delivery lines joining with one another into one common delivery line on the downstream side, check valves provided in the delivery lines upstream of a point where the delivery lines join with one another, a hydraulic cylinder driven by a hydraulic fluid introduced through the common delivery line, and a hydraulic reservoir. The pump failure alarm system comprises pressure sensors for detecting respective delivery pressures of the hydraulic pumps, bypass lines having one ends connected to the delivery lines at points upstream of the check valves and the other ends connected to the hydraulic reservoir, solenoid switching valves for opening and closing the associated bypass lines, an alarm display unit for giving an alarm in correspondence to each of the hydraulic pumps, and a controller.

Abstract: An apparatus for hydraulically operating a rear cover, covering top or the like (1) on a vehicle, with at least one double-acting hydraulic working cylinder (3), which, on the one hand, is connected to the vehicle and, on the other hand, to the covering top, includes working chambers (8, 9) in connection with each one side of a switched pressure source (12) via one check valve (10, 11) each, wherein both of the check valves have an mutually releasing device and each of the working chambers parallel with respect to the check valves is kept via a pre-stress valve (15, 16), which steers into the tank, at a specified pressure level. To realize, in a simple and safe way, a passive wedging protection, in at least one connection line (4, 5) to the working cylinder (3), a line (22) enters the tank (17), in which a proportional pressure valve (23) is inserted which is controlled by the control electronics and is equal to the exact pressure that is necessary for the movement of the covering top (1) or the like.

Abstract: The invention provides an in-line low supply pressure alarm device powered solely by supply flow of pressurized gas from a gas supply for providing an alarm signal when supply gas pressure is below a selected minimum pressure. The alarm device includes a manifold having an input port for communicating with the supply gas supply, an output port for conducting the gas downstream and a manifold chamber disposed therebetween. Gas powered alarms such as an audible reed alarm or a visual pneumatic alarm are connected to the manifold chamber via an alarm supply conduit, and produce an alarm signal when pressurized gas passes to the alarms. An supply gas pressure sensor, in communication with the manifold chamber, produces an actuating flow of pressurized gas by activating a pressure switch, in response to sensing of an supply gas pressure below the selected minimum pressure.

Abstract: A line, especially for delivery of liquefied gas at ambient temperature, has two solenoid valves connected in series with an intermediate section of the line between them. In normal operation when both valves are closed, the isolated intermediate section contains liquid which absorbs heat from the atmosphere and/or from a heater, and the resulting increase in pressure is detected by a pressure sensor. If either valve fails to close fully to shut off flow, the intermediate section is not then isolated, so the absence of a signal from the sensor (the valves being set to close fully) indicates that at least one of them has not properly closed, and an alarm is given.

Abstract: A device worn by a first diver provides a warning of conditions of danger and/or emergency to a second diver positioned at a distance from the first diver. The device includes a device for detecting the pressure in the compressed-air tanks, a device for transducing the detected datum, and a device for indicating the aforesaid datum.

Abstract: A method and system for monitoring integrity of a filter (25) of a smoke or fire detector system. The system has a detector chamber (14) into which light is passed from a light source incorporated into a light source control circuit (10). Scattered light is detected by a light scatter detector (12). Controller circuit (16) receives signal from the detector (12) and makes a cumulative count over time of the number of dust particles detected.

Abstract: A system is disclosed for checking gas pressure and gas leakage in one or more gas cylinders. The system particularly detects the state of gas pressure in a gas cylinder during ion-implantation, monitors for the existence of any gas leaks in the gas cylinders, and informs the manufacture process manager of the results of checking and monitoring using a communications device. This minimizes any loss of time due to equipment stoppage and protecting workers from any poisonous gas leaks.

Abstract: A rate of rise detector assembly (16) for use with explosion suppression equipment (14,18). The detector assembly includes a pressure sensor or transducer (20) and a controller (22). The pressure transducer continuously measures the pressure in a protected area and sends signals representative of the pressure to the controller. The controller samples the transducer every 200 .mu.Sec to obtain a series of successive pressure measurements. The sampled pressure measurements are then stored in a memory table (28) having five positions. Each time the table is filled, the five pressure measurements are averaged to obtain an integrated mean pressure value having a sample time of 1 mSec and then erased from the table so that it can be filled with subsequent measurements. This results in the calculation of a series of mean pressure values each having a sample time of 1 mSec.

Abstract: A method and apparatus for checking the integrity of an autolubrication system for large trucks, busses and the like includes an autolubrication system which includes a pump in communication with a plurality of conduits for forcing lubricants through the conduits under pressure. Preferably the conduits are subdivided into main conduits which are formed of steel, manifolds which receive the lubricants from the main conduits, and a plurality of at least partially flexible runner lines extending from the manifolds to lubrication receiving points. In accordance with one aspect of the method and apparatus, the pump can be activated from a remote location so as to enable the user to feel the runner lines with his or her hands immediately following actuation of the pump to ensure that a discharge pulse can be felt, thereby indicating that lubricant is properly passing through the other line.

Abstract: Apparatus and methods for monitoring a characteristic of fluid flow through a fluid dispenser that permit adverse flow conditions to be monitored, analyzed and displayed to an operator. The monitor samples either the static or firing pressure a predetermined number of times and calculates an average static and firing pressure over the sampling period. The average pressure values are compared to high and low warning and alarm limits and warning and alarm error codes are produced as a function thereof. In addition, individual sampled values are compared to the high and low warning and alarm limits and pressure values exceeding the limits during a sampling period are counted. Warning and alarm error codes are produced as a function of the counted values exceeding predetermined count values.

Abstract: The invention relates to a pressure switching device of the type used in motor vehicles and includes a pressure sensor 21 arranged in a housing 3, which generates an electrical signal U according to the pressure p of a pressure medium or monitored fluid transmitted through a supply opening 15 of housing 3. The pressure switching devices includes an interpretation and switching unit 55 adapted to received the electrical sensor signal U and is further adapted to compare the sensor signal with at least one switching threshold value to trigger a switching function or a sequence of switching functions upon the electrical sensor signal exceeding and/or falling short of the switching threshold value.

Abstract: A paperless recorder for recording pressure and alarm condition data from a fire controller for a fire pump control system. The fire pump is connected a pipe network which has a pressure sensor for sensing pipe pressure. The recorder is connected to the pressure sensor and checks for pressure changes. When a pressure change is detected, it is stored in an electronic memory. Pressure readings are also periodically stored in the electronic memory. The recorder may also monitor alarm voltages and alarm contacts which may also be stored in the electronic memory. The stored data may be transmitted to a computer via modem or port connection for further analysis.

Abstract: An apparatus (10) comprises an inflatable vehicle occupant protection device (12) and an inflator (20) for inflating the inflatable vehicle occupant protection device. The inflator (20) has a wall (32) defining a chamber (40) in the inflator. Inflation fluid is stored at a predetermined pressure in the chamber (40). The apparatus (10) further comprises a first device (102) for generating electrical energy. The first device (102) is located in the chamber (40). A second device (106, 108) senses a change in the predetermined pressure and transmits a signal indicative of the change in the predetermined pressure through the wall (32). The second device (106, 108) is located inside the chamber (40) and is electrically connected to the first device (102). A third device (122, 124) senses the signal. The third device (122, 124) is located outside of the chamber (40).

Abstract: An automated gas cylinder monitoring system includes: a data storage collar associated with a gas cylinder including a resident memory and an insulated housing, the insulated housing being configured for coupling with a gas cylinder; a read/write probe for writing data to and receiving data from the resident memory of said data storage collar; measuring devices for determining the volume of gas in a gas cylinder; and a host computer for transmitting information to and receiving information from the read/write probe.

Abstract: A safety system (10) for a materials handling device, for example fork lift truck, conveyor, comprises a sensing head (11) linked to a pressurization control unit (12). The sensing head (11) monitors the level of explosive vapors in proximity to the device relative to low explosive level (LEL). When a level of explosive vapors of below 25% LEL are detected, the pressurization control unit (12) maintains the supply of an inert gas for a supply (13) to at least one sealed enclosure which encloses any hazardous components in the device at substantially atmospheric pressure. When a level of explosive vapors above 25% LEL is detected, the pressurization control device (12) is operable to increase the supply of inert gas to the enclosure (14) to being the pressure in the enclosure (14) to greater than atmospheric pressure.

Abstract: The asset monitoring system and associated method includes an asset monitor for providing a remotely located central station with information relating to a container, such as a trailer, both during tethered periods in which the energy storage reservoir of the asset monitor is electrically connected to an external power source, such as the electrical system of a tractor or truck, and during untethered periods in which the energy storage reservoir of the asset monitor is electrically untethered or disconnected from the external power source. As a result, the energy storage reservoir is recharged by energy received from the external power source during tethered periods and supplies energy to the asset monitor during both tethered and untethered periods. The asset monitor also includes a controller for controlling its operations. The controller includes tether status determining means for separately identifying tethered periods and untethered periods.

Abstract: A modified air activated pressure valve is described, together with a method for its manufacture, that has a pressure sensitive switch located in the inlet chamber and in the outlet chamber. These pressure sensitive switches are preset by the user to output a finite voltage (typically about 5 volts) only when they are exposed to a pressure that exceeeds some value. The outputs of both switches may then be displayed, as needed. Additionally, a display circuit is provided that gives an output signal only when both the inlet and the outlet chambers are at or above their intended pressures.

Abstract: The system is adapted to receive input signals relating to the pressure in a firefighter's breathing system as well as ambient temperature and motion of the firefighter. An audible alarm is activated to indicate a potential emergency situation relating to low remaining air time, impending thermal breakthrough or lack of motion of the firefighter.

Abstract: An improved speed reducer assembly is provided. The assembly comprises an input shaft, an output shaft and a gear train interfacing the input shaft and the output shaft to effect a desired angular velocity ratio between the input shaft and the output shaft. A housing defines an interior area in which the gear train is disposed, the housing being configured to hold lubricant within the interior area. A pressure sensing device is mounted on the housing in communication with the interior area. The pressure sensing device is configured to output a pressure signal responsively to fluid pressure within the interior area. A second housing may be provided to sealingly enclose a portion of the pressure sensing device outside the speed reducer housing.

Abstract: A safety cap for containers under steam pressure contains internally a diaphragm that is actuated by the pressure of steam in such a way as to break the mechanical connection between a closure member forming part of the cap and screwed onto the container, and a knob forming part of the cap and by means of which the latter can be screwed on and off. In order to increase the safety features of the cap, the latter is fitted with a manometer, incorporated in the cap and readable from the outside, which detects the pressure of steam in the container.

Abstract: A wave motion detector system for a swimming pool includes a transducer responsive to positive and negative pressure changes in swimming pool water and operative to generate corresponding electrical signals. Comparators are responsive to the electrical signals, and operative to generate a crest signal while the positive pressure exceeds a predetermined positive threshold level, and a trough signal while the negative pressure exceeds a predetermined negative threshold level. A band pass filter prevents electrical signals having a frequency greater than a predetermined upper frequency, and lower than a predetermined lower frequency from passing from the transducer to the comparators. A pulse width discriminator is responsive to the crest signal and the trough signal and is operative to generate a qualified crest signal if the crest signal remains active for a first predetermined time interval, and a qualified trough signal if the trough signal remains active for a second predetermined time interval.

Abstract: The method consists in: i) making a series of recordings of the density of the gas at regular time intervals during a nighttime period by means of a temperature-compensated pressure sensor fixed on the outside of the envelope and communicating with the gas via a duct formed through the thickness of the envelope; ii) processing the density recordings of the gas acquired during the nighttime period in hourly intervals, each hourly interval giving rise to an hourly mean value for the density of the gas; iii) processing the hourly mean values obtained at the end of each hourly interval to give a daily mean value for the density of the gas at the end of the nighttime period; and iv) determining the leakage rate from the envelope by taking the difference between mean densities obtained at the ends of two different nighttime periods.

Abstract: A steam generator with automatic supply having a level sensor arranged in a zone of a vessel located at a set threshold level, the sensor measuring the temperature and comparing it with a reference temperature, in order to establish whether a liquid reaches the threshold level, and an adjustment means acting in relation to the steam tapping operations so that the sensor temperature varies in relation to the level of liquid over a variation range, wherein the reference temperature remains within the variation range.

Abstract: A pressure alarm for sewage treatment systems such as waste-water or sewage treatment tanks which require water level control. In a preferred embodiment the pressure alarm includes a pressure sensing apparatus which includes a tee or elbow located in a tank or system aerator air line, a nipple set into the tee leg of the tee or the elbow and a ball float fitted with a shaft or neck extending through the nipple and receiving an air deflector. According to the method of this invention, the air deflector projects into the run of the tee or the elbow responsive to floating of the ball float upwardly in a high water condition in the treatment tank or system. Extension of the air deflector into the run of the tee or the elbow causes a pressure drop through the tee or elbow as air is deflected from the run of the tee through the tee leg or elbow.

Abstract: A portable fire extinguisher assembly includes a fire extinguisher with a tank containing fire extinguishing material, a valve for metering release of the fire extinguishing material, and a gauge displaying pressure within the tank, and a docking station in communication with the fire extinguisher. An electronic circuit in communication with the fire extinguisher and the docking station issues a signal upon detection of predetermined conditions, including at least one predetermined internal condition and at least one predetermined external condition. The fire extinguisher electronic circuit includes cooperative male and female electrical/communication connection elements defined by the fire extinguisher and docking station.

Abstract: An interface pressure measurement device, comprising a sensor comprising two sensor sheets formed from thin flexible plastic material, each sensor sheet has a sensor area having flexible conductive ink printed thereon comprising a conductive surface with an electrical lead such that when the sensor sheets touch, an electrical contact is present forming a sensor switch, and the sensor also has sensor tubing. A digital device is connected to the sensor by the sensor tubing. The digital device comprises an enclosure, a push button, pressure transducer, signal conditioning, microcontroller with processor, analog-to-digital converter, memory, clock, display, buzzer and battery/power supply wherein the processor interrupts the battery/power supply current flow to shut off the digital device after a preset time.

Abstract: Apparatus and methods for monitoring a characteristic of fluid flow through a fluid dispenser that permit adverse flow conditions to be monitored, analyzed and displayed to an operator. The monitor samples either the static or firing pressure a predetermined number of times and calculates an average static and firing pressure over the sampling period. The average pressure values are compared to high and low warning and alarm limits and warning and alarm error codes are produced as a function thereof. In addition, individual sampled values are compared to the high and low warning and alarm limits and pressure values exceeding the limits during a sampling period are counted. Warning and alarm error codes are produced as a function of the counted values exceeding predetermined count values.

Abstract: A pressure gauge of a tire pressure indicator for a set of pneumatic tires of a vehicle includes a casing formed with an aperture and adapted to be secured to a metal wheel of a respective one of the pneumatic tires such that the casing is concealed by the respective one of the pneumatic tires, and a signal generating device disposed in the casing. The signal generating device wirelessly transmits a pressure signal when pressure within the respective one of the pneumatic tires is not within a predetermined normal operating pressure range.

Abstract: An alarm device, an improved squeeze-pad hydraulic system for a squeeze truck, and a method for converting an existing squeeze-pad hydraulic system of a squeeze truck into a squeeze-pad hydraulic system that alerts the operator of the squeeze truck when dangerously high hydraulic pressures are approached within the squeeze-pad hydraulic system are described. The alarm device comprises: an alerting device, operationally responsive to an electrical signal, having an input terminal for receiving the electric signal, and an alarm threshold switch comprising: a pressure transducing element in fluid communication with the hydraulic lines in a manner such that hydraulic fluid within the hydraulic fluid lines will exert a pressure on the pressure transducing element, and an electrical switching device, in electrical connection with the input terminal, for directing the electrical signal to the input terminal.

Abstract: A pressure detection apparatus including a pressure detection diaphragm, pressure detection circuit for outputting a pressure detection signal proportional to a pressure applied to the pressure detection diaphragm and clamping circuit for clamping the pressure detection signal to a predefined maximum or minimum value when the detected pressure signal is larger than the maximum value or less than the minimum value. Signal clamping by the clamping circuit is cut-off or cancelled when the pressure applied to the pressure detection diaphragm causes an operational error. This operational error may be detected by forming part of the clamping circuit on a semiconductor diaphragm of the sensor. Also, a failure detection circuit may be used to detect sensor failure and then cancel signal clamping.

Abstract: The present invention provides a self-contained breathing apparatus ("SCBA") having a personal alert safety system ("PASS") fully integrated therewith. The PASS is structurally integrated with the SCBA such that it is protected from damage by both the air cylinder and the frame. The integrated PASS device is not only automatically activated when the SCBA is being used but can still be activated manually if the SCBA is not in service. Additionally, the integrated PASS device utilizes a unique electrical/mechanical connection assembly between its various parts which greatly increases its ruggedness and durability.

Abstract: A flow alarm includes a magnetic switch that is maintained open so long as catalyst flow is maintained and an air flow switch that is closed responsive to flow of air through an associated conduit. The associated conduit supplies air via a solenoid valve to a pneumatic whistle. When flow of catalyst falls below a pre-set threshhold, the magnetic switch closes completing the circuit with the solenoid valve causing the solenoid valve to open and allowing air flow to the pneumatic whistle to signal the reduction of catalyst flow.

Abstract: A portable fire extinguisher includes a tank defining a volume containing a fire extinguishing material and further defining a tank outlet, and a valve assembly mounted at the tank outlet. The valve assembly includes a valve housing, a valve disposed relative to the tank outlet for metering release of fire extinguishing material from the volume, a valve trigger mounted for movement of the valve between a first position for containing fire extinguishing material within the volume and a second position for metering release of fire extinguishing material, and a gauge disposed in communication with the volume for display of pressure condition of fire extinguishing material within the volume. The portable fire extinguisher further includes an electronic circuit (31,32') mounted thereupon to issue a signal, e.g., an audio or visual signal upon detection of a predetermined condition, e.g.

Abstract: An indicating device includes a housing that is separated into two sub-chambers by a flexible diaphragm. A indicating member is carried by the diaphragm so that the diaphragm and the indicating member move, within the housing, responsively to changes in the pressure of the air flowing through an air intake system caused by restrictions in or clogging of the air intake filter. The indicating device incorporates an electromechanical sensor for monitoring the position of the diaphragm and producing an output signal responsive thereto. In one embodiment, the sensor is a potentiometer which produces an output signal which varies continuously between a first value when the diaphragm is at its unrestricted position and a second value when the diaphragm is at its restricted position. In a second embodiment, the sensor includes a switching circuit which produces a switched output signal which varies between at least three states corresponding to three different diaphragm positions.

Abstract: A electronic water utility monitoring system including a control box for the system positionable within the house of a user. Further provided is a first electrical line from the control box to a source of potential within the house. Associated therewith is a second electrical line from the control box to a water line for the house. Also included is a flow metering device mounted on the second electrical line to determine the rate of flow of the water within the water line. Finally, an electrical circuit is included for controlling the box. Such electric circuit has a port for allowing coupling with a conventional computer thereby allowing the storing of the rate of flow of water and further calculating the amount of water consumed over a predetermined amount of time and the price of water consumed.

Abstract: A vacuum controlling apparatus is provided. The vacuum level of a vacuum chamber can be accurately maintained by measuring and controlling the vacuum level of the vacuum chamber by using six parameters: desired pressure, predetermined time for reaching the desired pressure, predetermined temperature, actual pressure, actual time for reaching the desired pressure, and actual temperature.

Abstract: An apparatus for hydraulic actuation of a hinged cover on a vehicle having a working cylinder such that work spaces within the cylinder are respectively connected, via check valves, to a reversible pressure source. The check valves respectively contain a reciprocal unclosing facility, and the work spaces are connected, via a pilot valve, in parallel to the check valves. Between the one of the work space and one of the check valves, an emergency valve guiding off to the tank is interposed and is shut off during normal operation of the apparatus to allow a safe emergency actuation of the hinged cover.

Abstract: The multifunctional personal alert safety system of the present invention includes a portable safety monitoring device which is removably coupled for independent operation to an external self contained breathing apparatus (SCBA) containing a source of pressurized air. The portable safety monitoring device comprises a motion sensor unit, an alarm and a control having an activated position and a deactivated position. In addition the system includes a pressure switch which is responsive to the flow of pressurized air from said self contained breathing apparatus above a predetermined minimum level for causing the control to activate putting the motion sensor unit and alarm in an operational mode. Once in an operational mode the motion sensor and alarm remain operational independent of further operation of the pressure switch. A manual switch is also included for operating the portable monitoring safety device independent of the self contained breathing apparatus when the control is deactivated.

Abstract: A fluid flow monitor has coaxial conductive annular supports separated by an insulating gasket and connected by a conductive member. One support has a lesser external diameter and a smaller internal diameter than the other to reduce the chance of accidental short circuiting. Wires are attached to each support, a third wire supplies a floating ground to ensure monitor tripping is not caused by a ground fault. Tabs on the inner perimeter of the supports may mount the conductive member.

Abstract: The present invention is aimed to propose a method for minimizing erroneous shift to a water depth measurement mode by judging whether shift to a water depth measurement mode is caused by normal operation or erroneous detection and for automatically getting out of the water depth measurement mode even in the case of erroneous shift to the water depth measurement mode. Instantaneous shift to a water depth measurement mode is prevented when the water depth judging circuit 5 judges that a water depth value Ddpt from the measurement arithmetic processing circuit exceeds a predetermined value and that the water detection switch 6 detects no water contact, and a time information display mode is automatically returned even in the case of erroneous shift to a water depth measurement mode.