IPC Definitions - January 01, 2012
E21B 47/04 - Definition
This group covers:
Processes or apparatus for measuring the distance from the surface to a particular point in a borehole e.g. the bottom of the borehole or the top of a fluid or fluent, non-gaseous substance in the borehole.
Attention is drawn to the following places, which may be of interest for search:
Measuring liquid level in general | G01F |
Measuring depth in general | G01B |