Integration of instrumentation and control systems to meet the requirements of deep diving

Summary form only given. The commercial diving companies have been following the oil companies to greater and greater depths in the exploration for new oil deposits. During the first half of the 1970´s, this has meant that divers, instead of working the 150to 500-fsw range in systems designed for 600-fsw operation, are now expected to work in depths from 500 to 1500 fsw. Divers´ equipment and techniques have barely managed to keep pace with the requirements of the deeper depths, but the move towards deeper water has created new problems for the designers of chamber systems. Diving beyond 600 fsw requires the use of sophisticated communications, gas analysis, and environmental monitoring and control systems. The requirements placed on the instrumentation have reached a point where the instruments used in the field must equal the quality of those used in hyperbaric laboratories. In depths of this magnitude the tolerable physiological range of oxygen in the divers breathing mixture is less than the degree of error exhibited by some analyzers. The chamber temperature must be accurately controlled, as even a degree variation in the temperature can cause the divers discomfort. Those problems and the others caused by the in- crease in depth capability have been at- tacked in a piecemeal fashion, though interim solutions have been achieved in most cases. The problem has now become one of how to integrate the systems to provide the maximum in diver safety and comfort, while also maintaining or increasing the efficiency and ease of operation. Tarrytown Labs, has approached the design of a Control Van for 1000-fsw chamber operation as an opportunity to put recent advances in instrumentation and computers to work for the diving industry. The Control Van uses a computer to monitor chamber environmental parameters, fill out the dive log, and provide the de- compression profiles. Computer control is also extended to the decompression con- troller to allow the use of fewer topsi- e personnel, while increasing the precision with which the decompression profile is followed.