Pneumatic extensometer, especially for a creep measuring cell

摘要

1,106,888. Measuring creep - extensometers. COMMISSARIAT A L'ENERGIE ATOMIQUE. July 18, 1966 [July 23, 1965], No. 32094/66. Headings G1M and G1S. A pneumatic extensometer comprises a basic detector 1 including a creep measuring cell 2 and bellows 3, a reference detector 4 adjusted by calibrated blocks 5, pipes 8b, 8r supplying nozzle heads 10b, 10r with a neutral gas from a common pipe line 8, gas flow being controlled by pressure regulators R 1 - R 3 . Capillary tubes C 1 b, C 1 r, C 2 b, C 2 r, C 3 b, C 3 r interconnect the creep measuring cell and the reference detector and are provided with bellows 16, 19, 22, pressure changes in the bellows being indicated on gauges 33, 35, 37, 40, 41 and recorded on gauge 43. Each detector comprises a body 23 (see Fig. 2) an outlet port 12 delimited by a nozzle 26, and cone 27 which is integral with a measuring rod 29 which, in use, lies in contact with the object to be tested. Movements of the rod are detected pneumatically, the pneumatic circuit being similar to a Wheatstone Bridge arrangement.