Surgical instrument for dissecting tissue

A surgical instrument comprising:

• a body;
• an elongated shaft extending from the body;
• an end effector disposed at and supported on the distal end of the elongated shaft, the end effector including first and second jaw members moveable relative to one another between an open position and a clamped position;
• a clamping rod extending from within the body, through the elongated shaft, and operatively associated with the end effector to transition the first and second jaw members between the open and clamped positions, the clamping rod having a piston disposed at a proximal end thereof;
• a moveable handle pivotally mounted to the body and pivotable between an unactuated position and an actuated position;
• a measurement mechanism including a cylinder, a biasing member, and a locking member, the biasing member disposed within the cylinder and disposed over the h proximal end of the clamping rod distal to the piston, the cylinder operatively associated with the moveable handle such that as the moveable handle is moved towards the actuated position, the cylinder is moved proximally such that the biasing member urges the clamping rod proximally to move the first and second jaw members towards the clamped position.