Abstract: A leak in a membrane on top of a horizontal roof deck is located by applying conductive wires on the membrane underneath the aggregate in a grid pattern. A measuring and switching circuit generates voltage having a positive attached to the roof deck and a negative attached to the wires. The circuit has a relay for each wire which can be switched between a current sensor system and the negative potential. The sensor system is arranged to sense at each of the wires in turn the current flowing from the roof deck through any leak in the membrane to the wire. A micro-processor operates the relays in turn to connect all the other wires to the negative as a shield while each wire is sensed. From the output of the grid the changes in current in the x and y directions are analyzed to locate the leak in the membrane.

Abstract: A telecommunications optical fiber is secured against intrusion by detecting manipulation of the optical fiber prior to an intrusion event. This can be used in a non-locating system where the detection end is opposite the transmit end or in a locating system which uses Fresnel reflections and Rayleigh backscattering to the transmit end to detect and then locate the motion. The Rayleigh backscattering time sliced data can be stored in a register until an intrusion event is detected. The detection is carried out by a polarization detection system which includes an optical splitter which is manufactured in simplified form for economic construction. This uses a non-calibrated splitter and less than all four of the Stokes parameters. It can use a polarimeter type function limited to linear and circular polarization or two linear polarizers at 90 degrees.

Abstract: A moisture detection sensor is used in a building structure to detect moisture penetration is a flat self-adhesive tape. It includes a substrate of dielectric, hydrophobic material. Two elongate, parallel, conductors are secured to the top surface and a protective layer of non-hygroscopic, water pervious material secured over the conductors. A pressure sensitive adhesive on a bottom surface of the substrate is covered with a release sheet. The sensor may include moisture probes which penetrate the protective layer, the respective conductors and the substrate and to extend into a building component to which the substrate has been adhered. Each probe is made from a conductive, corrosion resistant material. This is particularly useful with water absorbent building materials, such as wood, where the surface may appear dry, but the body is impregnated with water. The preferred moisture probe is a U-shaped metal staple driven by a power stapler.

Abstract: A telecommunications optical fiber is secured against intrusion by detecting manipulation of the optical fiber prior to an intrusion event. This can be used in a non-locating system where the detection end is opposite the transmit end or in a locating system which uses Fresnel reflections and Rayleigh backscattering to the transmit end to detect and then locate the motion. The Rayleigh backscattering time sliced data can be stored in a register until an intrusion event is detected. The detection is carried out by a polarization detection system which includes an optical splitter which is manufactured in simplified form for economic construction. This uses a non-calibrated splitter and less than all four of the Stokes parameters. It can use a polarimeter type function limited to linear and circular polarization or two linear polarizers at 90 degrees.

Abstract: A telecommunications optical fiber is secured against intrusion by detecting manipulation of the optical fiber prior to an intrusion event. This can be used in a non-locating system where the detection end is opposite the transmit end or in a locating system which uses Fresnel reflections and Rayleigh backscattering to the transmit end to detect and then locate the motion. The Rayleigh backscattering time sliced data can be stored in a register until an intrusion event is detected. The detection is carried out by a polarization detection system which includes an optical splitter which is manufactured in simplified form for economic construction. This uses a non-calibrated splitter and less than all four of the Stokes parameters. It can use a polarimeter type function limited to linear and circular polarization or two linear polarizers at 90 degrees.

Abstract: A moisture detection sensor self-adhesive tape is used in a building structure to detect moisture penetration and includes a substrate of dielectric, hydrophobic material. Two elongate, parallel, conductors are secured to the top surface of the substrate and a protective layer of non-hygroscopic, water pervious material secured to the to the top surface of the substrate, over the conductors. A pressure sensitive mounting adhesive is placed on a bottom surface of the substrate and covered with a release sheet. The sensor may include moisture probes adapted to penetrate the protective layer, the respective conductors and the substrate and to extend into a building component to which the substrate has been adhered. The preferred moisture probe is a U-shaped metal staple configured to be driven in by a conventional power stapler.

Abstract: A defect in a horizontal or vertical seam at the edge of a roof membrane is detected by applying a DC voltage between the roof deck a probe in the form of a flexible wetted sponge and wiping the sponge probe over the seams. The current to the probe is detected and indicated to the operator so that the operator may determine a maximum current at the defect. The receiver provides an audible signal emitter to the operator and includes a calibration circuit arranged to automatically maintain, despite changes in voltage applied between the roof deck and the peripheral conductor, a “0” set calibration point so as to indicate at the calibration point when zero difference in voltage is detected. Conductors can be applied to the membrane to define an area to be tested within the conductors.

Abstract: A method of monitoring moisture in a building is carried out using moisture detectors, which provide an output resistance value ranging from a dry value in the absence of moisture and different wet values in the presence of moisture depending on the quantity of moisture. Rather than emit an alarm based solely on a moisture threshold, a risk assessment of potential damage is calculated for at least a part of the building using the wet values from the moisture detectors for the sensor zones using as input data the wet values and as a first additional factor a value which is indicative of a total area of the moisture as provided by the number of sensor zones that are responding with a wet value and as a second additional value the number of consecutive time periods that the sensor zone has reported wet value. The calculation can use computer modeling to calculate a risk factor for growth of mold or a risk factor for growth of timber decay fungi.

Abstract: A leak in a membrane on top of a horizontal roof deck is located by applying conductive wires on the membrane underneath the aggregate in a grid pattern. A measuring and switching circuit generates voltage having a positive attached to the roof deck and a negative attached to the wires. The circuit has a relay for each wire which can be switched between a current sensor system and the negative potential. The sensor system is arranged to sense at each of the wires in turn the current flowing from the roof deck through any leak in the membrane to the wire. A micro-processor operates the relays in turn to connect all the other wires to the negative as a shield while each wire is sensed. From the output of the grid the changes in current in the x and y directions are analyzed to locate the leak in the membrane.

Abstract: Some or all of the optical fibers of a single-mode or multi-mode cable are monitored for intrusion by transmitting through the fibers a signal which can be analyzed for changes in its characteristics which are indicative of movement as a prelude to an intrusion event. To avoid independent monitors of all of the fibers, in some cases the same light signal is looped through a plurality of the fibers in series by passive jumpers. Switches can be used to disconnect out those fibers which are compromised. As an alternative a plurality of separate monitoring signals can be provided each associated with its own sensor where unique combinations of the signals are transmitted through separate fibers allowing a higher number of fibers to be monitored than the number of signals.

Abstract: A telecommunications optical fiber is secured against intrusion by detecting manipulation of the optical fiber prior to an intrusion event. This can be used in a non-locating system where the detection end is opposite the transmit end or in a locating system which uses Fresnel reflections and Rayleigh backscattering to the transmit end to detect and then locate the motion. The Rayleigh backscattering time sliced data can be stored in a register until an intrusion event is detected. The detection is carried out by a polarization detection system which includes an optical splitter which is manufactured in simplified form for economic construction. This uses a non-calibrated splitter and less than all four of the Stokes parameters. It can use a polarimeter type function limited to linear and circular polarization or two linear polarizers at 90 degrees.

Abstract: A moisture detection sensor is used in a building structure to detect moisture penetration. The sensor is a flat adhesive tape of a substrate of dielectric, hydrophobic material. Three or four elongate, parallel, conductors are secured to the top surface and a protective layer of non-hygroscopic, water pervious material is secured over two of the conductors so that they are exposed to surface moisture. One or two of the conductors are covered by an insulating layer to prevent moisture access. Pairs of moisture probes along the length of the tape penetrate the insulating layer, the respective conductors and the substrate and to extend into a building component to which the substrate has been adhered. A diode guide arrangement allows a monitoring unit to monitor the exposed conductors for surface moisture and the penetrated conductors for moisture in the component by reversing polarity of the voltage across the conductors.

Abstract: A telecommunications optical fiber is secured against intrusion by detecting manipulation of the optical fiber prior to an intrusion event. This can be used in a non-locating system where the detection end is opposite the transmit end or in a locating system which uses Fresnel reflections and Rayleigh backscattering to the transmit end to detect and then locate the motion. The Rayleigh backscattering time sliced data can be stored in a register until an intrusion event is detected. The detection is carried out by a polarization detection system which includes an optical splitter which is manufactured in simplified form for economic construction. This uses a non-calibrated splitter and less than all four of the Stokes parameters. It can use a polarimeter type function limited to linear and circular polarization or two linear polarizers at 90 degrees.

Abstract: A signal which varies over time is monitored to determine an alarm condition, where the sample stream of digital values from an A/D converter is divided in to equal length pieces and a Fourier Transform (FT) algorithm is used to transform each piece of the stream into a three dimensional dataset including frequency domain amplitude, frequency and time. A Frequency Envelope is calculated by taking the maxima over the time dimension for a period of time, leaving a two dimensional frequency domain amplitude vs frequency dataset which is compared with new data arriving to determine the alarm condition for each element of the Frequency Envelope either by applying a constant delta additively or multiplicatively or by using a “leaky bucket” algorithm.

Abstract: A defect in a roof membrane is detected by applying a DC voltage between the roof deck and a perimeter conductor and using a detection probe pair to provide a signal indicative of the differences in voltage detected by the pair of probes so as to allow the operator to locate the defect by moving the probes to different locations. The probes are mounted on a rigid common frame such that the probe pair has a fixed separation and the frame includes a handle portion which allows ready manipulation of the frame carrying the probes by the operator. The receiver provides an audible signal emitter to the operator and includes a calibration circuit arranged to automatically maintain, despite changes in voltage applied between the roof deck and the peripheral conductor, a “0” set calibration point so as to indicate at the calibration point when zero difference in voltage is detected.

Abstract: A defect in a horizontal or vertical seam at the edge of a roof membrane is detected by applying a DC voltage between the roof deck a probe in the form of a flexible wetted sponge and wiping the sponge probe over the seams. The current to the probe is detected and indicated to the operator so that the operator may determine a maximum current at the defect. The receiver provides an audible signal emitter to the operator and includes a calibration circuit arranged to automatically maintain, despite changes in voltage applied between the roof deck and the peripheral conductor, a “0” set calibration point so as to indicate at the calibration point when zero difference in voltage is detected. Conductors can be applied to the membrane to define an area to be tested within the conductors.

Abstract: A defect in a roof membrane is detected by applying a DC voltage between the roof deck and a perimeter conductor and using a detection probe pair to provide a signal indicative of the differences in voltage detected by the pair of probes so as to allow the operator to locate the defect by moving the probes to different locations. The probes are mounted on a rigid common frame such that the probe pair has a fixed separation and the frame includes a handle portion which allows ready manipulation of the frame carrying the probes by the operator. The receiver provides an audible signal emitter to the operator and includes a calibration circuit arranged to automatically maintain, despite changes in voltage applied between the roof deck and the peripheral conductor, a “0” set calibration point so as to indicate at the calibration point when zero difference in voltage is detected.

Abstract: A leak in a membrane on top of a horizontal roof deck is located by a manually operable carriage which is swept over the upper surface of the membrane on the roof deck. A measuring and switching circuit generates a voltage having a positive attached to the roof deck and a negative attached to conductive brushes on the carriage. The brushes are arranged to form an outer peripheral contact with an inner contact inside the outer contact. Thus the presence of a leak is detected by the outer set of conductive brushes at distance from the leak and by the inner conductive brush when directly over the leakage site.

Abstract: A leak in a membrane on top of a horizontal roof deck is located by a manually operable carriage which is swept over the upper surface of the membrane on the roof deck. A measuring and switching circuit generates a voltage having a positive attached to the roof deck and a negative attached to conductive brushes on the carriage. The brushes are arranged to form an outer peripheral contact with an inner contact inside the outer contact. Thus the presence of a leak is detected by the outer set of conductive brushes at distance from the leak and by the inner conductive brush when directly over the leakage site.

Abstract: A leak in a membrane on top of a horizontal roof deck is located by applying conductive wires on the membrane underneath the aggregate in a grid pattern. A measuring and switching circuit generates voltage having a positive attached to the roof deck and a negative attached to the wires. The circuit has a relay for each wire which can be switched between a current sensor system and the negative potential. The sensor system is arranged to sense at each of the wires in turn the current flowing from the roof deck through any leak in the membrane to the wire. A microprocessor operates the relays in turn to connect all the other wires to the negative as a shield while each wire is sensed. From the output of the grid the changes in current in the x and y directions are analyzed to locate the leak in the membrane.