Abstract: A conduit has a core and an axial length susceptible to being pinched and chafed by other structure adjacent the conduit. An inner semiconductive layer extends the length of the conduit susceptible to being pinched and has a reference point adapted to be electrically connected with a detecting circuit for detecting a pinch and/or a computing unit for determining the location of a pinch. A resiliently compressible electrical switching layer, which is nonconducting when not pinched and conducting when pinched, is superposed against the inner semiconductive layer.

Abstract: A method for accumulating stress damage induced by temperature differentials in a rotor of a high pressure steam turbine utilizes a representation of stress damage corresponding to a period of continuous temperature change. A counter variable associated with the representation of stress damage is incremented each time there is a significant change in direction of change in stress induced in the rotor. Accumulated stress damage is calculated by summing the products of each counter variable times a coefficient of stress damage corresponding to that counter variable. Accumulated stress damage is added to previously accumulated stress damage, calculated prior to resetting of the counter variables, to produce total accumulated stress damage. The total accumulated stress damage is printed on a permanent storage medium, such as paper, and it is compared with an alarm setpoint. If the alarm setpoint is exceeded, a message is sent to the operator and the operation of the steam turbine may also be adjusted.

Abstract: An apparatus for positive muscle training has a motor-driven auxiliary force device for applying a force to aid the force applied by the trainee to overcome a weight or other counterforce. A control device senses the speed of movement of a cable caused by the force applied by the trainee and actuates the motor of the auxiliary force device when the speed falls below a predetermined value. The control device causes the auxiliary force to increase gently from zero until the predetermined value is reached once more.

Abstract: A multifunctional basketball monitoring unit that allows visual display and print out of a total baskets made score and the percentage of total baskets made of total baskets attempted in free throw and goal shooting either under time pressure or with no time limitation.

Abstract: A portable reserved parking alarm system including an electric motor contained in a housing mounted on a base plate and having a gear box mechanically connected to one end of an eccentric rod member whose other end is pivotally connected to a mast member, the lower end of said mast member being pivotally mounted on said base plate, said motor causing movement of said mast upon being energized by electrical means activated by a radio frequency signal, said electrical means including means for activating an alarm whenever said mast member is moved other than by action of said motor.

Abstract: A novel system for determining the magnitudes of loads on rotating helicopter components from signals remotely measured on the helicopter fuselage is characterized by a processor which decomposes the measured signals into corresponding Fourier components and extracts selected components therefrom. A programming module performs a multiplication on the respective Fourier components to correlate the measured components with corresponding determinative parameter values. The parameter values are established in a calibration process which is characterized by determination of the independent values of a measured signal set using a Jones orthogonalization process. The signals output from the coefficient programming module are provided to a multiplying resolver which receives synthesized reference sinusoids from a digital processor and generates time dependent signal components therefrom. These signals are ultimately summed in an analog summer circuit whose output signal corresponds to the desired parameter signal.

Abstract: A signal conversion circuit converts variations in resistance into an electrical signal. The conversion circuit comprises both a bridge circuit and a single operational amplifier with a capacitor between them to store voltage samples produced by an unbalancing of the bridge. The bridge circuit has a detector element such as a strain gauge for providing a resistance variation. A capacitor is connected through switches to both the bridge circuit and signal operational amplifier. The switches operate in a sequence whereby the operational amplifier is disconnected from the capacitor during the storage of the sample and the bridge is disconnected from the capacitor during intervals while the charged capacitor is connected to the amplifer.

Abstract: An arrangement for automatic release of occupant protecting devices in vehicles, particularly power vehicles, by means of producing a control signal in response to a deviation from an acceptable position or an acceptable condition of a vehicle, the arrangement comprises a sensor including a base plate provided with at least one coil through which a high-frequency alternating current flows, a seismic mass composed of an electrically conductive material at least in the region of the coil and movably suspended near the base plate so as to be in an operative connection with the coil, a pendulum-like suspending member which supports the seismic mass so as to enable a substantially parallel movement of the seismic mass relative to the coil, and a perforated member which coats the coil, the perforated member being composed of an electrically conductive material and provided with at least one slot.

Abstract: A device for monitoring the performance of an automated machine tool. Specifically, the device of the invention monitors the operation of a reciprocating appliance. The device of the invention measures the amount of force being exerted by the appliance during each operation. This information is analyzed by the device to determine the dimensional characteristics of each work piece. If the device calibrates that a particular work piece possesses an improper dimensional characteristic, e.g. thickness or hardness, then the device is designed to initiate a safety function, e.g. terminating the operation of the machine tool.

Abstract: A method and apparatus for the determination of automobile and truck tire revolutions wherein said apparatus adhered to the tire detects each revolution by the flexing of that section of the tire.

Abstract: This invention relates to a movement monitor that is suitable for detecting movement, and also provides an alarm should movement that is being monitored cease. The movement monitor is particularly suitable for use with humans or other living organisms where breathing movement is being monitored. In considering the use of the movement monitor on human infants, it is particularly useful for preventing death from Sudden Infant Death Syndrome. The movement monitor comprises a rigid base member for supporting the moving object which is being monitored, and is provided with a reaction means which is secured to the base member and arranged to extend over and be held in contact with the moving object. A transducer is placed between the rigid base member and the moving object such that when movement occurs, the reaction means causes force to be applied to the transducer.

Abstract: Systems for automatically determining whether a conductive, volant game device touches down in bounds or out of bounds on a playing surface. The system includes boundary line and out of bounds circuits which can be completed by the touchdown of the game device thereupon. A control unit processes the signal generated by each completed circuit and turns on a signal which is coded to indicate whether the device touched down in bounds or out of bounds. Associated circuits and control capabilities provide a signal when the game device touches the top of a net or other barrier in games in which that type of contact is significant.

Abstract: A security awning window is presented with increased safety factors which grant protection against both adverse weather conditions and unauthorized entry. Alarm struts span the window which, if deflected act as a switch for an audible alarm and also engage the panels to provide increased burglar or adverse weather protection.

Abstract: An impact detection apparatus (10) includes a device that utilizes multiple sensor elements (11) to determine whether or not a ball lands in or out on a tennis court (12). The sensor positions (13-134) are adjacent to the various boundary lines of the tennis court (12). The sensor elements (11) are layered devices which, when compressed, generate an electrical impulse. The impulse is then analyzed through various signal processing means so that an impact caused a sensor (11) to be compressed may be characterized as being a ball, a footstep, or some other object. In this way, near-simultaneous impacts of a ball and a footstep can be distinguished. If the impact is characterized as a ball that has landed out, a control console (206) will give a visual and/or audible signal so that players, and officials if present, are informed that the ball was out.

Abstract: A parking sensor having a base for attaching to a vehicle, a flexible probe for contacting an impending obstruction, a contact for producing an electrical signal responsive to deflection of the probe, a lamp, buzzer, or other transducer for indicating the electrical signal, and a filter for preventing operation of the transducer during spurious occurrences of the electrical signal. The filter can include a timer for activating the transducer when the electrical signal continues beyond a first interval, which can be from 0.05 to 1.0 second. Also, the timer prevents activation of the transducer beyond a second, longer interval that is typically 10 to 40 seconds for terminating the indication (and power drain) when further corrective action by an operator of the vehicle is unlikely.

Abstract: A user-programmable sensor system for generating an alarm signal upon detection of an alarm event is disclosed. The system is particularly suited for use in vehicle security systems. The system employs a three axes accelerometer as a shock/motion detector, and the transducer outputs are summed and the composite signal filtered to provide several channels, each covering a specific frequency or frequency band. The outputs of the channels are digitized and processed by a microprocessor. An event is characterized by seveal signal parameters with an alarm event triggered by the simultaneous occurrence of several predetermined conditions, and not just one condition. The limit values for the signal parameters which are required to qualify a shock/motion event as an alarm event may be readily programmed by the user at any time or place.

Abstract: A torsion member (12) has opposing protruding end elements (4, 6) configured for transmitting torque therebetween. A first contact mechanism (20, 26) is mounted to a surface (10) of one end (4) of the torsion member (12). The first contact mechanism includes a movable contact (26') disposed between the end elements (4, 6) of the torsion member. A second contact mechanism (18, 28) is mounted to a surface (11) of the other end element (6) of the torsion member (12). The second contact mechanism includes a movable contact (28') disposed near the first contact (26'). The first contact (26') and second contact (28') move toward each other whenever torsion is applied to the torsion member (12). Means (30, 40) are provided for changing the distance between the first and second contacts (26', 28'), and for producing a signal whenever the first and second contacts touch.

Abstract: An alarm locator module for use in association with a picket fence having a plurality of picket elements disposed along a tubular rail, each picket being armed with an intrusion detection device connected to a three line supervised conductive loop contained within said rail and in constant communication with the intrusion locator module. The intrusion locator module supplies voltage and current down a first line of the loop, having a plurality of resistive elements disposed in spaced apart relationship along a portion of its length. Current normally flows back up the loop via a return line to ground, unless an intrusion is detected, in which case the intrusion detection device causes a short between the first line and a second line of the loop thereby causing current to flow through the second line back to the intrusion locator device, which is capable of detecting and reporting the intrusion.

Abstract: The Merchandise Theft Deterrent Sensor deters theft of display merchandise by implementation of a sensor directly into an anti theft detection system. The Merchandise Theft Deterrent Sensor is attached directly to goods through the use of a pair of specially designed adhesive surfaces; one surface in the form of a peripheral rectangular window surrounds as second surface which is directly attached to a centrally located, moveable piston and electrical membrane switch assembly. The piston membrane switch assembly activates an alarm means if motion on the order of two thousandths of an inch occurs. The Merchandise Theft Deterrent Sensor is assembled in a small rectangular molded plastic container, wherein the closeout lid of the container is flexible to enable in-place checkout of the sensor by minor depression of the lid to activate the moveable piston and electrical membrane switch assembly.

Abstract: A safe for a loaded hand gun has a box which includes a receptacle for containing the gun. The receptacle has a bottom providing a mounting surface. A lid is hingedly mounted on the box and is movable between a closed position covering the receptacle and an open position in which the gun is accessible. A locking device normally holds the lid in its closed position, and a touch pad mechanism is operable only by authorized personnel provides for releasing the locking device when access to the gun is desired, permitting the lid to move to its open position. The touch pad may be a numerical touch pad, an alphabetical touch pad or a fingerprint indentification touch pad. The mounting surface has a mounting hole for use in attaching the safe to another structure. A pressure sensitive pad is affixed to the mounting surface at the mounting hole and is positioned to be overlapped by the head of a mounting screw.

Abstract: The operating condition of sliding components inserted between a slide or sprocket chain and a guide system for such chain is continuously monitored by an electrical loop conductor which passes through a plurality of sliding components. The electrical conductor is provided with an electrically insulating jacket which is preferably also heat resistant. The loop conductor is inserted into a monitoring circuit including a relay for activating an alarm when the loop conductor is either interrupted or when its insulation is damaged. This happens when any one of the sliding components through which the loop conductor passes, are sufficiently damaged. The alarm signal may also be used to stop the further drive of the sprocket chain.

Abstract: A contact sensor for detecting points on a grid where the sensor is being contacted on opposing sides by teeth surfaces or other contacting points. The contact sensor includes two sets of parallel electrodes which are each formed of a thin, flexible supporting sheet. The electrodes are coated with a thin, resistive coating. Two such electrode structures are oriented at approximately right angles to create a grid where the intersecting electrodes cross separated by the resistive coatings. The resistive coatings may be made from conventional resisitive inks and are optionally separated by a separation material, such as talcum or mesh. In the absence of an external force, the material between the electrodes sets provides a high resistance between intersecting electrodes.

Abstract: The present invention provides a compressible sensor for use in adjusting the distance between two parallel surfaces until the distance is within predetermined limits or tolerances. The sensor includes an electrically insulating flat support having two separated electrodes on each side thereof, two resiliently deformable members of different resilient deformabilities each one located between the two separated electrodes and contacting one side of the electrically insulating flat support, and two electrically conductive members each in contact with one of the resiliently deformable members. Each electrically conductive member extends over the two separated electrodes so that it can establish an electrical connection with either separated electrode when the resiliently deformable member is compressed. A signaling circuit is used to determine which electrodes are electrically connected and detects when the distance between the two parallel surfaces is within the accepted tolerances.

Abstract: An axle weight load indicator device for mounting on a motor vehicle to detect when a pre-set axle weight has been exceeded. The device includes an electrical switch, an axle-mounted permanent stop and a retractable probe mounted in a housing which is operably associated with the electrical switch and permanent stop. When not in use, the probe is retracted into the housing to ensure that false signals are not emitted during movement of the motor vehicle. When operable, the probe is positioned to make contact with the permanent stop when a pre-set load limit has been exceeded. Continued loading causes activation of the electrical switch. The electrical switch trips an alarm to warn of the excess load.

Abstract: An indicator apparatus has multiple stages to effectively handle data processing, particularly raw data from a mechanical load cell, such as those used to monitor loads in the mechanical workings of a torque arm reducer. Processing of such raw data is split into parallel operations relating to both signal level and signal polarity functions. This multi-staged approach enables increased precision as to both functions due to tailoring of the data inputs to different stages. Use of staged circuitry to effect the separated functions also readily permits the presence of an unobtrusive monitor level signal output. Combined with other features, a limit detector and alarm permits accurate provision of both a stable response to low frequency steady state mechanical data and to fast-acting high frequency transient/dynamic data contained therein. Indicated polarity changes signify alternating tension and compression in the mechanical couplings of a load cell.

Abstract: Apparatus for monitoring structures and structural members for overloads has an elongated frangible closed ended tube containing a dense, visible liquid. The tube includes a central reduced cross-sectional area for forming a weak portion thereof. The tube is enclosed in a transparent shield and the tube and shield resiliently attached to the structure to be monitored. The frangible tube is designed to cause the weakened area to fracture when the tube and structure are exposed to a preselected level of an acceleration force, causing the liquid to be deposited in the shield as an indication of an overload.

Abstract: A motion sensor unit which includes a sensor assembly for monitoring whether or not the inclination of a mobile member is in excess of a predetermined reference angle and outputting a pulse signal in case the inclination is greater than the reference angle; a detector for monitoring whether or not the duration of the pulse signal is in excess of a predetermined reference time and, in the case of any excess, outputtting a signal representing that the inclination of the mobile member is greater than the reference angle and is continuous for more than the reference time; a sensor assembly for outputting a pulse signal inverted in accordance with the value of a shock given to the mobile member; and a detector for monitoring whether or not the cycle of the pulse signal is shorter than a predetermined reference time and outputting a shock detection signal when the cycle is shorter than the reference time.

Abstract: A triggering device and a method of operation which may be used in a vehicle-mounted gas bag protection device, in which a bag fills with gas upon impact of the vehicle. During normal conditions, a small current passes through a detonator associated with the gas generator. This current is supplied by an auxiliary power supply, including a capacitor, which is charged through a diode from a main vehicle battery. When impact occurs, an increased current flows through the detonator to cause gas to be generated. To detect malfunctions, a voltage associated with the detonator is monitored and then alarm is generated when the monitor voltage exceeds a predetermined range. To prevent the generation of false malfunction alarms, the predetermined range is determined with respect to the voltage produced by the auxiliary power supply and not the main battery of the vehicle so that fluctuations in the voltage associated with the main battery of the vehicle do not produce false alarms.

Abstract: A device for monitoring environmental exposure includes an element whose electrical properties change, in a predetermined way, in response to the environmental exposure. The element may be part of a tuned circuit or of a shield for a tuned circuit. In either case, when the tuned circuit is interrogated, preferably by an r.f. or microwave signal, it emits a signal whose intensity depends on the electrical properties of the element. Thus, an incremental environmental exposure can be measured by a change in the signal intensity. The device is particularly useful for monitoring the condition of perishable materials, because it can be located with the perishable inside a packaging material during both storage and interrogation.

Abstract: An automatic locking device for linkages subjected to undesirable mechanical stresses comprises a transducer with transmits an electrical signal as a function of the mechanical stress received, and feeds it to a coil which generates an electromagnetic field causing locking of the linkage.

Abstract: An electronic circuit adapted to receive conditioned force signals from a three-axes load cell mounted on the arm of a robot and provide a stop signal for use by a controller of the robot. The circuit compares the sum of the absolute value of the forces with a variable reference signal. A force trip relay and a masking relay are connected in parallel to provide the stop signal when both the resulting sum is greater in value than the reference signal and the robot is in an operating condition in which high forces do not normally occur.

Abstract: A patient monitor includes an enclosure which is secured to the bed of a patient. The enclosure is electrically connected with a nurse's call panel and the enclosure serves to mount a jack which is electrically connected to the nurse's call panel. This jack includes a normally closed switch which is opened when a mating plug is installed in the jack. The plug is connected by a cord to the gown of the patient in the bed. When the patient attempts to leave the bed the patient's motion pulls the plug from the jack, thereby allowing the switch to close and signalling via the call panel the patient's attempt to leave the bed.

Abstract: In a rotary drive system, mechanical means for sensing turning torque gented by the load forces. The sensing means is designed to operate with minimal effect on normal operation of the drive system.

Abstract: A load sensor generates a signal representing the amount of force applied to a workpiece during each blow of a multi-blow forming process. In a two blow process, a first amplifier is connected to the load sensor for amplifying the load sensor signals representing both blows in the forming process. A first gain control circuit is connected to the first amplifier for adjusting the amount of amplification to a first predetermined level. A logic control circuit is connected to the first amplifier for generating a first enabling signal during the first blow in the forming process and a second enabling signal during the second blow in the forming process. A second amplifier is connected to the first amplifier for amplifying the load sensor signals representing only the first blows in the forming process. A second gain control circuit is connected to the second amplifier for adjusting the amount of amplification to a second predetermined level.

Abstract: Constant or transient forces and displacements between a motion snubber and its associated load are detected and converted to an electrical signal. Electrical signals from the detection devices are transmitted to a receiving device which is electrically connected to a recording means. The signals from a plurality of detecting devices are encoded to identify the snubber having the detected force and displacement.

Abstract: A visual display unit for displaying variations in the quotient of applied load and safe working load for a vehicle, such as a mechanical handling or load-carrying vehicle, has a pictorial representation of the vehicle applied to a display panel and a plurality of lights positioned around the representation and arranged to be illuminated at different predetermined quotient levels so as to provide a primary visual indication of an increase in load towards an unsafe condition. In addition the lights and the representation are mutually disposed such that a secondary visual indication is provided showing the cause of an increase in applied load and how it may be reduced.

Abstract: A ski stress signaling device comprising a pair of strain gauges mounted on the top surface of each of a pair of skis with one strain gauge in front of the boot and the other strain gauge behind the boot. Each pair of strain gauges is connected by electrical conductor wires to a bridge circuit. The magnitude and polarity of the voltage output of the bridge circuit is determined by the amount of strain measured at the tops of the skis by the four gauges. The amplified output of the bridge circuit is used by a pair of LED (light emitting diode) drivers to control the illumination of two pluralities of LEDs mounted around the periphery of a pair of goggles worn by the skier.

Abstract: A device for sensing and indicating movement of a golf player's head adapted to be worn upon the golfer's cap proximate the side of the head, the motion sensor adapted to sense motion of the golfer's head up and down and side to side, the motion sensor device outputting an electrical signal in accordance with movement acceleration sensed to a signal processing unit which generates a variable audio frequency electrical signal in accordance with electrical signal received from the motion sensor, and an audio output device receiving the electrical signals from the signal processing unit, the audio output device being such as an earphone worn in or near the golfer's ear to indicate to the golfer in real time motion made by his head at and during the time that he makes his golf swing.

Abstract: A vehicle equipped with a spring and shock absorber suspension has a piezoelectric wafer interposed between the spring and a part of the vehicle in such manner as to cause the wafer to be subjected to a compressive or decompressive force in response to relative vertical movement of the vehicle part and the suspension. The application of such force to such wafer results in the generation of an electrical current pulse which is transmitted to an indicator mounted within the vehicle in a position to enable the driver to monitor the condition of the shock absorber.

Abstract: A device is provided for use with an actuator having an actuator shaft which indicates when the torque on the actuator shaft exceeds a predetermined limit. The device comprises a housing which carries a pair of limit switches. A shaft extension is operatively connected with the actuator shaft so that axial force on the actuator shaft, which is proportional to the shaft torque, is transmitted to the shaft extension. A hub and Belleville washer arrangement translates the axial force on a shaft into a proportional axial movement of the hub while a radially extending member from the hub includes a portion positioned adjacent the limit switch. Thus, when the axial force in one direction on the shaft exceeds a first predetermined amount, the radially extending member activates one limit switch which in turn is connected to an indicator.

Abstract: Alarm circuit wiring is completely enclosed within a jalousie-type window and includes positive and negative terminals connected respectively to the louver blades and to the shafts which rotate the blades between open and closed positions. An insulating air space is provided between each blade and its center shaft to prevent normally any flow of current therebetween. Any attempt to force the louver blades of the jalousie open will result in the completion of the electrical circuit by causing the blade to deform through the air space so that contact with the center shaft is made. The switch contacts of the circuit consist of a rectangular tube provided along one edge of each louver blade, and a rectangular center shaft housed within the tube, the rotation of which by a conventional turning mechanism causes the blades to open and close.

Abstract: The method and apparatus for preventing runaway lowering of a hook block in an oil drilling rig characterized by monitoring the instantaneous values of hook load and speed and using these values together with parameters associated with the rig drawworks to calculate an energy value which must be dissipated during a braking stop by the drawworks brake. The brake or an emergency brake associated with the drawworks is automatically actuated when the calculated energy value reaches a predetermined value representative of the maximum energy absorbing capability of the brake. The brake may also be automatically activated when the position of the hook block reaches predetermined upper and lower limits.

Abstract: An ultrasonic line sensor including an elongated transmission line for longitudinal pressure waves, which changes transmission characteristics with change in the length of the line due to transverse mechanical loading, and also including apparatus for energizing the line with longitudinal pressure waves at a long term frequency which establishes a standing wave in the line, and for responding to short-term changes in the natural frequency of the line.

Abstract: A pressure operated electrical switch and an alarm system for use in hospitals and nursing homes is constructed such that a force is applied to the upper surface of a leaf spring therein. Once the load is reduced below a predetermined value the leaf spring will move to close/open a microswitch or electrical contact means. The normal force applied to the leaf spring is the load on the leg of the hospital bed when occupied. If the bed occupant gets out of the bed the load on the leaf spring is reduced below a predetermined value and the consequent movement of the leaf spring opens/closes the switch means to actuate the alarm.

Abstract: A door lock assembly having an electrical alarm system includes a piezoelectric element located between the lock bolt of the door lock and the lock frame in order to emit a signal to energize the electrical alarm system when pressure is applied between the lock bolt and the frame.

Abstract: An intrusion sensing line to be buried or emersed in a medium and operative to deliver electrical signals in response to pressure changes as the medium is stressed, the line including multiple metal shells each having a transducer bonded to a flexible diaphragm surface inside the shell, and the shells being spaced apart and joined by soft metal tubing, the tubing and shells being metal-to-metal bonded at all joints and sealed to retain a dry inert gas, and the transducers being insulated from the shells to which they are bonded and wired together, preferably with alternating polarities, by insulated wiring extending through the tubing and the shells.

Abstract: A method and apparatus for measuring a predetermined limit of deflection or stress of a load bearing means or beam such as a walking beam of an oil well pumping unit uses a spaced fixed arm mounted on said beam at one end and having a first sensor means attached near the other end with a second sensor mounted on said beam so that said beam deflects to produce a signal which can be used to sound an alarm or operate control means to relieve stress of said beam.

Abstract: An electronic sensor circuit is provided which generates predetermined frequencies corresponding to the resultant force vector of the gravitational and inertial forces. There is further provided electronic circuit means for generating an audible response which increases in intensity in correspondence with the magnitude of the deviation of the force vector from a defined datum. In the preferred embodiment an electrolytic transducer is used to sense gravitational and inertial forces and a phase detection circuit is provided to monitor the output and control the input generator for selection of a frequency corresponding to the deviation occurring.

Abstract: A glass breakage detector includes a cantilever assembly incorporating a base member having a first beam coupled thereto. The base assembly is secured to a pane of glass with the beam extending along an axis determined by the plane contaning the glass. A piezoresistive device is positioned on the beam and adapted to change its resistance upon deflection of the beam due to the breakage of said glass and based upon the application of a vector component of force as deflecting the beam. Other embodiments employ at least another cantilever assembly also having a beam and sensor with the beam directed relatively transverse to the first beam and adapted to respond to force components normal to said vector component.

Abstract: An overload warning system for fighter type aircraft combines analytical techniques of computing structural loads with flight conditions and aircraft control inputs to calculate the allowable load factor/control input on a real time basis. The flight conditions and aircraft control inputs are monitored by a microprocessor, which continuously monitors actual load factor, compares the answers with a computed allowable value and generates an output signal whenever a prescribed value is exceeded. This signal is available for transmission to aural or visual warning devices and for permanent recording.