reversible transit circle

reversible transit circle

[ri′vər·sə·bəl ′tran·zət ‚sər·kəl]
(engineering)
A transit circle that can be lifted out of its bearings and rotated through 180°, enabling systematic errors in both orientations to be determined.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.