Description

The FD-400 Series ultrasonic doppler flowmeters measure the flow of liquids that contain sound reflectors, suspended solids, or gas bubbles larger than 100 microns. These sophisticated instruments automatically adjust filtering and gain settings to produce reliable readings in a wide range of liquid and reflector conditions.

The FD-400 flowmeter transmitts ultrasonic sound through the pipe wall or from the probe tip into the flowing liquid by using piezoelectric crystals contained in the transducer and probe tip. The sound is then reflected by sonic reflectors suspended in the liquid and recorded by the receiver. If the sonic reflectors are moving within the sound transmission path, sound waves will be reflected at a frequency shifted (Doppler frequency) from the transmitted frequency. The difference between the 2 frequencies is directly proportional to the speed of the sonic reflectors, resulting in a liquid flow rate that is converted to various user-defined units.

Configuration of the FD-400 is accomplished via the front-panel keypad. A 2-line backlit LCD displays rate and total in user-selected units. Power supply options include AC and DC. Optional outputs include 4 to 20 mA, relays, and rate pulse.
Two transducer styles are available. The FD-400C clamp-on, non-intrusive transducer is recommended for most metal or plastic pipes. The FD-400C has a NEMA 6P (IP68) rating and is available in a high-temperature version, "=HT". The user can place these clamp-on transducers up to 305 m (1000') from the display enclosure. The FD-400I insertion probe transducer should be used on piping systems that do not permit ultrasonic penetration. The FD-400I inserts into the pipe wall and comes into direct contact with the flowing liquid.