Abstract: A particle detector, e.g. a smoke detector is described. In one form the detector includes a detection chamber and radiation source emitting a single beam of radiation. The detector also includes a radiation receiving system and an imaging system arranged to receive radiation from a common region of interest. Methods and systems for analysing the output of a particle detector are also disclosed.

Abstract: A particle detector, e.g. a smoke detector is described. In one form the detector includes a detection chamber and radiation source emitting a single beam of radiation. The detector also includes a radiation receiving system and an imaging system arranged to receive radiation from a common region of interest. Methods and systems for analyzing the output of a particle detector are also disclosed.

Abstract: A particle detection system including; at least one light source adapted to illuminate a volume being monitored at at least two wavelengths; a receiver having a field of view and being adapted to receive light from at least one light source after said light has traversed the volume being monitored and being adapted to generate signals indicative of the intensity of light received at regions within the field of view of the receiver; a processor associated with the receiver adapted to process the signals generated by the receiver to correlate light received at at least two wavelengths in corresponding regions within the field of view of the receiver and generate an output indicative of the relative level of light received at the two wavelengths.

Abstract: There is described a duct detector (1) and components (2, 3, 6) for duct detectors. In one form the duct detector (1) includes: a port unit (3) and detector unit (2). The port unit (3) is mountable to a duct in use so as to position one or more ports in the duct. The detector unit (2) includes a detection region. The port unit (3) and detector unit (2) are reconfigurable between a close coupled configuration and a separated configuration in which the units (2,3) are mountable with a variable separation between them and coupled by one or more elongate conduits (12A, 12B) to provide fluid communication between the units (2,3).

Abstract: An air sampling system for a low-temperature space is disclosed. The air sampling system includes an air sampling pipe for passing sampling air to an air sampling device, and a sampling conduit extending from the low-temperature space to outside the low-temperature space. The sampling conduit is connected to the sampling pipe. The sampling conduit is selectively accessible from outside the low-temperature space for removal of ice build-up within the sampling conduit. Also disclosed is a kit for an air sampling system. Also disclosed is a method, computing system, air-sampling device and air monitoring system that evaluates an air sampling network.

Abstract: A beam detector including a light source, a receiver, and a target, acting in cooperation to detect particles in a monitored area. The target reflects incident light, resulting in reflected light being returned to receiver. The receiver is capable of recording and reporting light intensity at a plurality of points across its field of view. In the preferred form the detector emits a first light beam in a first wavelength band; a second light beam in a second wavelength band; and a third light beam in a third wavelength band, wherein the first and second wavelengths bands are substantially equal and are different to the third wavelength band.

Abstract: A particle separation system for separating particles in an airflow upstream of a detection chamber in an aspirating smoke detector is disclosed. The particle separation system includes an airflow path for directing the airflow from an inlet to an outlet. The airflow path includes a first airflow path section in a first direction and a second airflow path section in a second direction, the first and second directions being different relative to each other. The airflow path also includes at least one electrically charged surface such that the airflow undergoes electrostatic precipitation as it traverses the airflow path. A method of separating particles in an airflow upstream of a detection chamber in an aspirating smoke detector is also disclosed.

Abstract: A particle detection system including a particle detector in fluid communication with at least two sample inlets for receiving a sample flow from a monitored region. The particle detector includes detection means for detecting the level of particles within the sample flow and outputting a first signal indicative of the level of particles within the sample flow. A flow sensor is located downstream of the sample inlets for measuring the flow rate of the sample flow and outputting a second signal indicative of the flow rate of the sample flow. At least a first sample inlet is normally open to the monitored region for receiving at least part of the sample flow. At least a second sample inlet is normally closed to the monitored region but is openable to the monitored region in response to a change in environmental conditions in the monitored region.

Abstract: A system and method of reducing the incidence of false alarms attributable to dust in smoke detection apparatus. The method includes obtaining at least two sample air flows, subjecting a first airflow to particle reduction and measuring the level of particles in the first airflow and generating a first signal indicative of the intensity. The method also includes measuring the level of particles in the second airflow and generating a second signal indicative of the intensity. The first signal is compared to a predetermined alarm level and, if the alarm level is achieved, the first and second signals are subsequently compared and an output signal is generated based on the relative difference between the first and second signals.

Abstract: A method of detecting one or more blocked sampling holes in a pipe of an aspirated smoke detector system. The method includes ascertaining the base flow of fluid through a particle detector using a flow sensor; monitoring subsequent flow through the particle detector; comparing the subsequent flow with the base flow; and indicating a fault if the difference between the base flow and the subsequent flow exceeds a predetermined threshold.

Abstract: There is described a filter arrangement for a particle detector for detecting particles in an environment. The particle detector can include one or more sensors for analyzing fluid in a detection region to produce sensor output. The filter arrangement includes structure defining flow paths, for conveying fluid from the environment towards the detection region, including a first flow path, which includes a filter, and a second flow path bypassing the filter. There is also provided a mechanism for controlling relative flow rates of fluid through the first flow path and the second flow path and a controller configured to receive the sensor output corresponding to at least two relative flow rates and apply logic thereto to generate an output indicative of a condition of the filter.

Abstract: The invention provides use of one or more emitted beams of radiation (16), for example, laser beam(s), in combination with an image capturing means (14), for example, one or more video cameras and/or optical elements to detect particles (30), for example, smoke particles, located in an open space (12).

Abstract: There is provided a fabric for use in a wearable article, the fabric having a first side directed to an inner side of the article as worn and a second side directed to an outer side of the article as worn and a second side directed to an outer article as worn, the fabric comprising a sheet formed of a substantially impermeable elastomeric material having perforations provided therethrough, the first and second sides being in airflow communication with each other through the perforations, each perforation having at least one relatively wide region along its length and at least one relatively narrow region along its length whereby the perforation defines an internal chamber at the relatively wide region, the internal chamber open to the first side of the fabric.

Abstract: A breathable insulating fabric is described, from which wearable articles such as garments or medical support fabrics or dressings can be made, in which an elastomeric insualating sheet (1) has perforations (4) which have relatively wide (5) and narrow (6) regions along their lengths to define an internal chamber (7) open to the inner side of the sheet as worn and sufficiently closed to the outer side of the sheet to permit air passing from the inner to the outer side of the sheet to accumulate in the chamber under increased pressure prior to passing to the outer side. The breathability of the fabric is adaptable to changes in the external conditions and the biological functions of the wearer.

Abstract: There is provided a laminated fabric comprising a sheet portion of a material compatible with human skin, the being adhered to a second sheet formed of a substantially impermeable material having perforations provided therethrough, each perforation having at least one relatively wide region and at least one relatively narrow region along its length to define an internal chamber open to a first ("inner") side of the sheet and sufficiently closed to the other ("outer") side of the sheet to permit air passing from the first to the other side of sheet to accumulate in the chamber under increased pressure prior to passing out to the other side of the sheet.

Abstract: A rotary external combustion engine wherein energy is supplied to a working space of the engine by direct injection into the stator of liquid water at a high temperature and pressure. The water acts as a heat-transfer medium. Some of the liquid water spontaneously vaporizes on injection, during the rotor. Liquid water is exhausted from the working space and recycled to an external heat exchanger for reheating prior to reinjection. The engine is capable of a thermal efficiency greater than that of the Rankine cycle.

Abstract: A rotary external combustion engine wherein energy is transferred to air acting as a working gas by injection into the air of liquid water at a high temperature and pressure. The liquid water is injected either directly into the working space in the stator or into a preliminary mixing chamber. The water acts as a heat-transfer medium for heating the air. Spontaneous vaporization of the liquid water on injection increases the pressure of the air which drives the rotor before being exhausted. The exhaust water is recovered and recycled. The working space is scavenged and refilled with a fresh charge of air.

Abstract: A reciprocating external combustion engine wherein energy is supplied to a working end space of the engine by direct injection into the cylinder of liquid water at a high temperature and pressure. The water acts as a heat-transfer medium. Some of the liquid water spontaneously vaporizes on injection, driving the piston. Liquid water is exhausted from the cylinder and recycled to an external heat exchanger for reheating prior to reinjection. The engine is capable of a thermal efficiency greater than that of the Rankine cycle.

Abstract: A reciprocating external combustion engine wherein energy is transferred to air acting as a working gas by injection into the air of liquid water at a high temperature and pressure. The liquid water is injected either directly into the cylinder or into a preliminary mixing chamber. The water acts as a heat-transfer medium for heating the air. Spontaneous vaporization of the liquid water on injection increases the pressure of the air which drives the piston before being exhausted. The exhaust water is recovered and recycled. The cylinder is scavenged and refilled with a fresh charge of air.