Welding apparatus having a safety feature

Abstract

Welding apparatus () having a safety feature comprising: two electrodes (), whereof at least one of said two electrodes is movably arranged in relation to the other electrode. The electrodes are in non-contact with each other and define a gap () in which an object () provided with an electrically non-conductive surface to be sealed may be inserted. The welding apparatus comprises an actuator () configured to move at least one electrode when activated to squeeze the object, a detector () configured to determine a clamping force when the inserted object () is squeezed between the electrodes, a distance sensor () configured to measure the distance between the electrodes. There is also a conductance sensor () configured to measure the conductivity of an object located between the electrodes () when the object () is squeezed, and optionally a position sensor () configured to detect the position of the object () inserted between the electrodes. The welding apparatus further comprises a processor configured to process the input from at least one of the detector (), the distance sensor () and the conductance sensor () to provide an output that indicates if there is a blood bag tube inserted between electrodes, or if it is a foreign object.