ULTRASONIC LIQUID FLOW TRANSMITTERS

CSLFB: The CSLF series of ultrasonic liquid flow transmitters are designed for use with building automation, energy management, and process control systems. Models include various sizes and connection types for liquid flow measurement.

FEATURES

• Dual Sensor, Bi-directional
• 2 Field selectable ranges
• Loop-powered 4-20mA 
• Zero Pressure Drop
• Several pipe size available
• Choice of connection
• No moving parts
• No initial calibration 
• Plug 'n Play 

DESCRIPTION
The CSLF series ultrasonic liquid flow transmitters are ideal for the measurement of flow rates of acoustically conductive liquids including most clean liquids and many liquids with entrained solids.

Main advantages include excellent long term stability, no pressure drop, no moving parts, broad fluid compatibility, high accuracy and low cost.

At the heart of the transmitter is a proprietary mixed signal ASIC which allows sophisticated timing, control and transducer drive circuitry to be combined on a single integrated circuit. The ASIC uses a special algorithum that is an improvement upon the standard single-path measurement technique. Using the "sing-around" method, the ultrasonic transducer alternates between transmitting and receiving to measure differences in flight time between upstream and downstream transmissions. A sound pulse is transmitted from an upstream transducer towards a downstream transducer like a traditional time-of-flight measurement. However, the received sound pulse then triggers a second downstream transmission that then triggers a third and so on for a specific number of cycles. This process is repeated in the upstream direction.

Because it takes an average flight time over multiple cycles to compute the difference in flight times, the approach yields a significant improvement in timing accuracy when compared with the time-of-flight difference of a single sound pulse in each direction. This algorithm, combined with the pico-second timing resolution of the ASIC, provides the precise time measurement capability necessary for compact, small diameter ultrasonic meters.

The output of the transmitter is unaffected by changes in fluid temperature, density and viscosity as the flow calculation is independent of the speed of sound.

Wetted materials include ULTEM® encapsulated ultrasonic transducers with a choice of elastomer seals and epoxy coated carbon steel body material.