A heat exchanger for a fluid handling system is disclosed. Sensors sense various aspects of the processing. The distal tip is bonded to the inner layer in the recessed region. Such small particle size dicarboxylate salts provide desirable properties within thermoplastic articles, particularly as nucleating agents, but apparently suffer from certain clarity issues and agglomeration problems, making utilization thereof less desirable for certain applications. The module is enclosed within an elongated handle that positions the center of mass for optimum balance of the instrument and the control switches for convenient operation according to the sense of touch.