. Collected reprints, Essa Institute for Oceanography. Oceanography signal amplifier is a solid state, variable gain, wide band DC differential amplifier of excep- {ional stability. Secular drift is ± 0. 02 % in 2 00 hours at constant temperature ; temperature sensitivity is on the order of % per degree centigrade. The power requirement is 1. 8 watts . Power for the entire package is about 2 1/2 watts. A null circuit is employed to electrically cancel the transducer output, thus permitting a highly expanded record of nearly linear response. In the models used to
. Collected reprints, Essa Institute for Oceanography. Oceanography signal amplifier is a solid state, variable gain, wide band DC differential amplifier of excep- {ional stability. Secular drift is ± 0. 02 % in 2 00 hours at constant temperature ; temperature sensitivity is on the order of % per degree centigrade. The power requirement is 1. 8 watts . Power for the entire package is about 2 1/2 watts. A null circuit is employed to electrically cancel the transducer output, thus permitting a highly expanded record of nearly linear response. In the models used to date a strip chart recorder pi-ovides an analog record. Future modifications will provide for digital recording, at first by photographing a milliampmeter, then later with the use of a high density digital ma- gnetic tape recorder. A transducer with the proper maximum operating depth is selected based on the depth anticipated on station. Within this inherent limit a wide range of actual observation depth can be tolerated without degrading the precision of the observation. This is possible because of the simple null circuit employed. With no signal the recorder is cente-red at zero. When the am- plified pressure-dependent signal is sufficient to move the stylus to either recorder limit, a contact is activated ; a simple servo mechanism displaces the stylus toward the center of the record. Thus, with continually increasing pressure the full recorder range will be repeated to correspond to each relatively small increase in pressure. In the operational models an increase in water depth of approximately 5 feet ( m) corresponds to the 4-inch (10 cm) record width . Aside from the high degree of compensation inherent in the transducer bridge circuit, no temperature compensation is employed. Instead components of extremely small temperature response have been employed, and the assembled components have been laboratory calibrated over anticipated temperature and pressure ranges. A
Size: 2066px × 1209px
Photo credit: © The Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., book, bookcentury1900, bookcollectionamericana, bookleafnumber255
