The hand held flow meter is a battery-powered ultrasonic flow meter with the capability of a full-size flow meter. It is carefully designed for portability and ease of use. The hand held flow meter is based on clamp-on transit-time flow measurement principle. It measures the flow rate of liquid in a pipe from outside of the pipe by using a pair of ultrasonic transducers. In general, the liquid should be full in the pipe, and should contain very little particles or bubbles. Examples of applicable liquids are: water (hot water, chill water, city water, sea water, etc.); sewage; oil (crude oil, lubricating oil, diesel oil, fuel oil, etc.); chemicals (alcohol, acids, etc.); waste; beverage and liquid food, solvents and other liquids. Due to the nature of clamp-on technique, the transducer installation is simple and no special skills or tools are required. Besides, there is no pressure drop, no moving parts, no leaks and no contamination. The hand held flow meter utilizes our proprietary technologies such as advanced signal processing, low-voltage transmitting, small signal receiving with self-adapting, and etc. It also incorporates the latest surface-mounting semiconductors and mini PCB design techniques. The built-in rechargeable Ni-H battery can work continuously for more than 10 hours without recharge. Features 0.5% of linearity Wide pipe size range 0.2% of repeatability 100 Pico-second time measurement resolution 1% of accuracy at velocity above 0.6ft/s. 0.5 second totalizing period 0.5% when on-site calibration is Built-in data-logger available Clam-on transducer. Easy to install and to maintain Bi-directional measurement Light weight, portable. Main unit 1.2lbs. 4 flow totalizers Also able to be used for long-term deployment Proprietary low-voltage transmission technology