Performance And Reliability In Open Path Gas Detection With Sieger Searchline Excel

The Sieger Searchline Excel infrared Open Path Gas Detector System for (OPGD) hydrocarbon gases from Zellweger Analytics, is ideally suited for offshore installations and on-shore hydrocarbon processing plants. It is designed to initiate plant shutdown procedures in the event of gas release and reduce explosion risk. It meets the needs of operators who demand that such instrumentation should provide virtually 100% availability to prevent downtime and loss of valuable productivity.

The Searchline Excel Open Path Gas Detector will monitor a hydrocarbon gas release or cloud as it passes through an invisible infra red detection beam, which operates over distances of 5 to 200 metres. It has been designed as a result of a customer partnership approach between Zellweger Analtyics and major oil and petrochemical companies who have been actively involved in its three year development from the design stage through to prototypes, field trials and the finished product.

OPGD is a highly effective means of monitoring flammable gas with significant advantages over point gas detectors which rely on gas reaching a detector at one given point or location. It is therefore possible that the prevailing wind l air direction or any change in direction may take a gas release away from a point gas detector. In addition, the further the point gas detector is away from the source of the leak, the greater the degree of dilution until the concentration is below a detectable level. A high intensity light source pulsed at a special coded frequency generates a much stronger infra red beam enabling it to penetrate further through fog and rain. Carefully selected sample and reference wavelengths makes Searchline Excel free from the problematic absorption of infra red light by the O-H bond of water vapour.

The receiver unit utilises unique solid state detectors offering the widest dynamic range and improved linear response to incident light compared to that employed on previous OPGDs. This, in conjunction with temperature compensation, provides exceptional baseline stability even under conditions of direct sunlight and rapidly changing temperature, fog or rain. Searchline Excel is guaranteed to be 100% solar immune and has extended operational availability in thick fog.

Ultra fast digital signal processing using the latest microprocessors enables rapid signal averaging and filtering. Searchline Excel automatically rejects interference from vibrations or bright reflections. Unique low energy internal heating prevents the formation of condensation or a build up of snow and ice over the optical surfaces thereby increasing system availability.

The latest surface mount electronics and optomechanics, have significantly reduced the size and weight of Searchline Excel, making it the world's smallest open path IR gas detector. This will allow easier retrofitting into crowded areas of plant whilst making it less prone to vibrational interference.

Zellweger Analytics - Sieger Division, 4331 Thurmond Tanner Road, P.O. Box 2100, Flowery Branch, GA 30542. Tel: 770-967-2196; Fax: 770-967-1854.