ClarkSonic ultrasonic flow transmitters are ideal for 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, broad fluid compatibility, high accuracy and low cost. Also, there are no moving parts.
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 algorithm 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 Brass body material.
Flow Range: Bi-directional, field selectable per "Standard Models" table
Accuracy: ±.75% of full scale
Operating Temperature: -40 to 180°F
Response Time: User Selectable, 2 or 10 seconds
Viscosity Range: 0.2 to 150 cSt (0.2 to 150 mPas)
Liquid Density: 30.6 to 74.9 lb/cu.ft. (490 to 1200 kg/m3)
Max. Working Pressure: 200 PSI
Pipe Sizes: 3/4", 1", 1 1/2", 2", 3"
Pipe Connections:
Sizes 3/4" to 2"- Female NPT, BSP
Size 3": ASME 150 or DIN 16 Flange
Electrical Enclosure: Integral to Body casting with gasketed cover; One 1/2"
NPT conduit connection (plugged when model ordered with metric threads)
and one M16 x 1.5 connection (plugged when model ordered with NPT threads)
Electrical Connections: Screw terminal connections on PC board
Enclosure Rating: NEMA 4 (IP 65)
Power: 18 to 36 VDC
Ultrasonic Transducers: ULTEM® Encapsulated Seals: EPDM, Buna-N, Neoprene™, FKM, or other Body Material: Brass (UNS C83600)
Analog: 2-wire, 4-20 mA output; Output is 4 mA from zero to min. flow
(see Standard Model table)
Error Detection: An optically isolated 10 mA (max. 48V no load voltage) sink
output is activated under certain detectable fault conditions, such as transducer
failure or overly noisey output due to flow stream anomalies, as might be seen due
to excessive bubble entrainment.
Direction of Flow: Optional output to indicate direction of flow is available.
Activation or deactivation of an optically isolated 10 mA (max. 48V no load voltage)
sink output indicates flow direction. Error detection is not available when this
option is ordered.

| Size/Connection | A | B | C | D | E | |||||
| Inches | mm | Inches | mm | Inches | mm | Inches | mm | Inches | mm | |
| 3/4" & 1" | 9.20 | 234 | 1.62 | 41.10 | 2.06 | 52.30 | 6.40 | 163 | 2.40 | 61.00 |
| 1-1/2" & 2" | 9.88 | 251 | 2.75 | 69.90 | 2.51 | 63.80 | 6.40 | 163 | 2.40 | 61.00 |
| Size/Connection | A | B | C | D | E | |||||
| Inches | mm | Inches | mm | Inches | mm | Inches | mm | Inches | mm | |
| 3" ASME 150 | 11.00 | - | Ø 7.50 | - | 3.16 | - | 6.50 | - | 2.50 | - |
|
80 mm DIN 16 |
- | 280 | - | 190 | - | 84.00 | - | 165 | - | 63.50 |
| Model | Pipe Size/Thread Size | *Field Selectable Full Scale Ranges (GPM) | *Field Selectable Full Scale Ranges (LPM) | |||
| Min. | Max. | Min. | Max. | |||
| CSLFB34 | 3/4" NPT or BSP | L | 0.18 | 15 | 0.72 | 60 |
| H | 0.31 | 25 | 1.20 | 100 | ||
| CSLFB10 | 1.0" NPT or BSP | L | 0.38 | 30 | 1.38 | 115 |
| H | 0.63 | 50 | 2.40 | 200 | ||
| CSLFB15 | 1.50" NPT or BSP | L | 0.50 | 40 | 1.80 | 150 |
| H | 1.00 | 80 | 3.60 | 300 | ||
| CSLFB20 | 2.0" NPT or BSP | L | 0.75 | 60 | 2.70 | 225 |
| H | 1.88 | 150 | 6.90 | 575 | ||
| CSLFB30 | 3" ASME Class 150 Flange 80 mm DIN Class 150 Flange | L | 2.48 | 200 | 9.00 | 750 |
| H | 4.96 | 400 | 18.00 | 1500 | ||
| *Other F.S. ranges can be specified | ||||||
| PLEASE CALL 1-800-253-2497 TO ORDER THESE ITEMS | ||||
| A | B | C | D | |
| Model | Pipe Thread | Units of Measure | Transducer Seal | |
| 3/4" to 2" | 3" | |||
| CSLFB34 | NPT= Female NPT | ASME= ASME Class 150 Flange | G= Gallons Per Minute (U.S.) | E= EPDM |
| CSLFB10 | B = Buna-N | |||
| CSLFB15 | BSP=Female British Standard Pipe (G) | DIN = DIN Class 16 Flange | L = Liters Per Minute | N= Neoprene® |
| CSLFB20 | V= FKM | |||
| CSLFB30 | ||||
| Options | ||||
| DF = Direction of flow output option | ||||
| *For non-listed ranges specify model followed by full span value | ||||
| Example: CSLFB15-50G = 50 GPM at 20 mA or CSLFB15-200L=200LPM @ 20 mA | ||||