1
general::
Also, feel the pulse of. Try to determine the intentions or sentiments of a person or group, as in These exit polls allegedly take the pulse of the voters, but I don't believe they're very meaningful. [First half of 1600s] Also see FEEL OUT.
American Heritage Idioms
2
general::
Phrase(s): take the pulse of something
Fig. to sample or survey something to learn about its progress or state. • Two executives came in to take the pulse of the local business unit.
McGrawhill's American Idioms And Phrasal Verbs