The new UPT868 Ultra-Pure Flow(tm) measurement system from Panametrics, Inc. (Waltham, MA) is an ultrasonic clamp-on system designed to give straight-through flow while maintaining 100% sealed integrity for high purity liquid such as deionized water and weak chemical solutions, says the company. The system consists of a clamp-on flow tube unit and a display. The flow tube unit is a PVC block with an ultrasonic transducer fixed at each end. Running through the PVC block is a straight run of 15 in. of PFA tubing that carries the fluid. Tubing sizes range from 3/8 to 3/4 in. dia.