Магнитоэлектрические осциллографы для экспериментальных геофизических исследований

Summary

The above paper contains a survey of light ray oscillographs and their basic parts constructed in the Institute of Physics of the Earth of the Acad. of Sci. of the USSR for geophysical measurements in the laboratory and terrain.

Two types of miniature galvanometers were developed for the oscillographs, which are composed of blocks of 6, 9, 12 or 14 with a common permanent magnet having a working field intensity up to 14000 Oe. Galvanometers of the type GB-III have a frequency in the range of 1 to 5 Hz, and galvanometers of the type GB-IV have a frequency in the range of 20 to 10000 Hz. The constants of these serially produced galvanometers are given in Tab. 1. The following quantities are given for each type of galvanometer: frequency (Hz), current constant (a/mm/m) and current sensitivity (mm/m/mA), internal resistance (Ω) and external resistance (Ω), critical (α=1) for type GB-III and optimum (α=0,7) for type GB-IV.

The optical systems and driving parts used with the oscillographs are briefly described. A brief survey of the technical characteristics of the oscillographs developed in the Inst. of Physics of the Earth, some of which are produced serially for the needs of other branches of science and engineering, is contained in Tab. 2. This table gives oscillographs with high recording speed for short-period measurements (1–5), oscillographs for longperiod recording (6–13) and universal oscillographs with a large range of recording speeds (14–24). With each type of oscillograph there is given the number of galvanometers, their frequency (Hz), width of recording paper (cm), range of recording speeds (cm/sec), type of drive and weight of complete oscillograph (kg).