Measure flow from outside a pipe. This new Portaflow PT500 Transit Time Flow Meter is designed for clean liquids like water, oils and most chemicals. Recommended for troubleshooting, spot checks and balancing flow. Strap-on sensors mount on the outside of plastic or metal pipes and ultrasonic signals are injected through the pipe between the two sensors. It works on any pipe diameter from 0.51 to 78” (13-2000 mm) OD. PT500 features include a large, backlit graphics display, 4-20mA output, data logger, RS232 and USB outputs, a user-friendly operating system with “Quick Start” calibration menu, plus ability to store calibrations for up to 20 different sites. Operates 16 hours on internal battery and recharges overnight.