A probe assembly for inserting a probe into a flexible or semi-rigid vessel or tubing having a distal aseptic connector for coupling to the vessel or tubing, the probe sheath comprising at least a portion that is rigid, the probe sheath extending longitudinally from the aseptic connector and having at least one inner longitudinal lumen configured to receive an elongate sensor or probe body and to permit longitudinal movement of the sensor/probe body within the probe sheath lumen, and an actuator for deploying a probe within the vessel or tubing by advancing the probe body through the aseptic connector to a position where the probe can measure at least one parameter within the vessel or tubing is disclosed herein.
