Clark Sonic Series CSLFC Carbon Steel Ultrasonic Liquid Flow Transmitter Manual
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Rev04009 USER MANUAL CLARK SOLUTIONS MODEL CSLFC The Model CSLFC is an ultrasonic transit time flow meter designed to accurately and reliably report the flow of non-compressible fluids in pipe diameters ranging from 4 inch to 10 inches. It is a 2- wire device reporting flow in the industry standard 4-20 mA protoͭcol. The meter introduces no pressure drop other than the pipe section which provides the means to position the ultrasonic transducers and to connect to the user's piping system. The small electronic board which implements all the func-tions to measure and report the flow is housed in the integral elecͭtronic enclosure and is sealed so as to protect the electronics from the environment. THEORY OF OPERATION Two ultrasonic transducers are positioned and angled so as to transmit and receive sound pulses that are launched at a flat reflec-tion point located on the opposing side of the pipe. The flight time of the sound pulse from the transmitting transducer to the receiving transducer will be shortened if the pulse is launched in the direction of flow and increased if launched opposite to the direction of flow. By alternating the transmitting and receiving transducers, the difference in these transit times can be used to calculate the velocity of the flow, which when multiplied by the area of the pipe, results in a measure of volumetric flow rate which is then used to set the current in the 4-20 ma loop proportional to the full scale value of the meter. The path of this sonic pulse traverses the pipe diameter twice and because of the generous spacing between transducers, the volume of fluid which influences the time of flight of this pulse is commensurate with the scale of the turbulence features in the flow. Turbulence by its nature has chaotic velocity components and by directing the sonic pulse through a volume comparable to the scale of this chaos, the effect on the flight time on any single measure-ment are much reduced, resulting in measurements that show less variation from the average. Stating it another way, a measure of the Standard Deviation of a number of measurements will be reduced, resulting in less uncertainty in the currently reported flow rate. clark A 4 USER MANUAL MODEL CSLFC ULTRASONIC FLOW TRANSMUTER IMPLEMENTATION The accuracy and precision of the determined flow rate is ultimately determined by the accuracy and precision with which one can measure the transit times. Clark Solutions 10 Brent Drive, Hudson, MA 01749 Tel. 978 / 568 3400 Fax 978 / 568 0060 www.clarksol.com

The Model CSLFC incorportes a proprietary ASIC (Application Spcifie IC ), which provides all the functions required to alternately transmit and receive sonic pulses and measure the transit times to picosecond accuracy. The ASIC implements the "Sing Around" method to launch and receive pulses, each received pulse initiating the next transmitted pulse. On any one measurement, a number of such cycles are used to accumulate the individual transit times which are then divided by the number of cycles to give an average of these measurements. A microprocessor provides the following functions:...

USER SELECTABLE OPTIONS There are three switches (FIG 3) accessible when the controller board is exposed. Their functions are as follows: Reset. o This is a small push button switch which when activated resets the software as would occur if the unit were power cycled. Օ Full Scale o This is a dip switch setting that allows the User to select between two pre-programmed full scale values for the pipe diameter currently used. See the Specification section for detail. Response Time o This switch setting allows the User to select two different update rates. In many applications, a longer...

Error Dtection: An optically isolated sink output is activated under certain dtectable fault conditions, such as transducer failure or overly noisey output due to flow stream anomalies, as might be seen due to excessive bubble entrainment. The optional Fault output is an optically isolated NPN transistor capable of sinking up to 10 ma from a voltage source of no more than 48 VDC. Caution: There is no current limiting on this output so care must be exercised to limit the sink current to less than 25 ma and insure that proper polarity, as shown in Fig.1, is observed else permanent damage may...

DIMENSIONS , CAUTION Model CSLFC is for measurement of liquid flows only Use only with liquids compatible with the materials of construction Maximum Pressure: 200 PSIG Maximum Temperature: 190oF Pipe Size Dimensions (Inches) A B C D E F Bolt Circle Diameter Number of Holes 4" 13.00 9.00 4.00 6.54 2.62 0.75 7.50 8 6" 16.00 11.00 5.09 6.54 2.62 0.88 9.50 8 8" 18.00 13.50 6.11 6.54 2.62 0.88 11.75 8 10" 22.00 16.00 7.18 6.54 2.62 1.00 14.25 12