Reply #7: This is what I found

[appleannie1]

quorum call - A call of the roll to establish whether a quorum is present. If any Senator "suggests the absence of a quorum," the Presiding Officer must direct the roll to be called. Often, a quorum call is terminated by unanimous consent before completion, which permits the Senate to use the quorum call to obtain a brief delay to work out some difficulty or await a Senator's arrival.

http://www.senate.gov/reference/glossary_term/quorum_call.htm

A quorum call or call to quorum is a parliamentary procedure used to summon absent members of a deliberative body if a quorum is not present.

http://en.wikipedia.org/wiki/Quorum_call