(under the class definition) Subject matter wherein information or intelligence pertaining to the walls of a passageway through the earth is obtained from a device which travels through the passageway and emits acoustic waves into the medium contained within the passageway (e.g., air, water) which are reflected from the walls back to the device and detected.
SEE OR SEARCH CLASS
73, Measuring and Testing,
152.16, for using vibration to measure a parameter of a borehole or equipment therein.
175, Boring or Penetrating the Earth,
40+, for borehole testing apparatus combined with significant boring or penetrating structure.