Dual frequency Doppler ultrasonic non-contact flowmeter. Velocity range 0.06 to 10 m/sec, accuracy +/-1%. Pipe size range 12~5,000 mm diameter. Data logging for 90,000 points, with PC software and interface cable for download via RS232C interface. Transducer temperature range -40~122 deg C. Analog output 4~20 mA. Battery operated, 12 h continuous use (8 hr recharge).