Abstract: An optical fiber is monitored for an intrusion event where reflected optical signals are divided into streams each associated with a respective location on the optical fiber. Blocks of the streams are selected each containing a plurality of streams and the streams are collated, for example by averaging, to create a single stream to which an algorithm is applied to create coefficients which are compared with a threshold value to generate an output indicative of disturbance of the fiber by an intrusion event. Each block representative of a length of the fiber is thus treated as a zone and the detection algorithm is applied to each. This creates a DAS system that does not require unique tuning as each zone is independently monitored.

Abstract: A chain having a plurality of inside links and guide links. The plurality of inside links each have a pair of apertures and are interleaved and connected to form rows. The plurality of guide links each have a pair of apertures and are placed outside of alternate rows of interleaved inside links to form guide rows. Connecting pins are received in the apertures and extend across the rows of the chain securing the links together. Spacing elements are found on opposite side of the chain, specifically between the guide links and the adjacent outermost inside links. The spacing elements act to maintain a spaced relationship between each of the guide link sand adjacent outermost inside links. At least one of the spacing elements on one side of the chain is a spring link holding the inside links in compressive frictional contact therebetween.

Abstract: A chain having a plurality of inside links and guide links. The plurality of inside links each have a pair of apertures and are interleaved and connected to form rows. The plurality of guide links each have a pair of apertures and are placed outside of alternate rows of interleaved inside links to form guide rows. Connecting pins are received in the apertures and extend across the rows of the chain securing the links together. Spacing elements are found on opposite side of the chain, specifically between the guide links and the adjacent outermost inside links. The spacing elements act to maintain a spaced relationship between each of the guide link sand adjacent outermost inside links. At least one of the spacing elements on one side of the chain is a spring link holding the inside links in compressive frictional contact therebetween.

Abstract: A power transmission chain having a plurality of inside links and guide links. Each inside link has at least one inverted tooth adapted to contact the teeth of an associated sprocket. Each link has a pair of apertures which are connected by connecting pins inserted through the apertures. The chain is provided with projections acting to maintain a spaced relationship between the guide links and the inside links. The spacing of the guide link away from the inside links is accomplished by spacing elements which may include projections formed on the guide link or an outer face of the outermost inside link, or by washers or spacers interposed therebetween.

Abstract: A power transmission chain having a plurality of inside links and guide links. Each inside link has at least one inverted tooth adapted to contact the teeth of an associated sprocket. Each link has a pair of apertures which are connected by connecting pins inserted through the apertures. The chain is provided with projections acting to maintain a spaced relationship between the guide links and the inside links. The spacing of the guide link away from the inside links is accomplished by spacing elements which may include projections formed on the guide link or an outer face of the outermost inside link, or by washers or spacers interposed therebetween.

Abstract: A power transmission chain having a plurality of inside links and guide links. Each inside link has at least one inverted tooth adapted to contact the teeth of an associated sprocket. Each link has a pair of apertures which are connected by connecting pins inserted through the apertures. The chain is provided with projections acting to maintain a spaced relationship between the guide links and the inside links. The spacing of the guide link away from the inside links is accomplished by spacing elements which may include projections formed on the guide link or an outer face of the outermost inside link, or by washers or spacers interposed therebetween.