Prepared by: Camron Seamons cbs@ccu Dept. of Electrical and Computer Engineering

1. ECE5320 MechatronicsAssignment#01: Literature Survey on Sensors and Actuators Topic: Ultrasonic Doppler Flow Sensors Prepared by: Camron Seamons cbs@cc.usu.edu Dept. of Electrical and Computer Engineering Utah State University 3/9/2007

2. Outline • Reference list • To probe further • Major applications • Basic working principle illustrated • A typical sample configuration in application (application notes) • Major specifications • Limitations • And many more relevant issues in applications (such as, how to choose, cost information, where to buy etc.) ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators

3. Reference list • http://www.nexsens.com/pdf/manuals/sontekargonaut.pdf • http://www.cidra.com/iss/technology/index.html • http://www.omega.com/toc_asp/frameset.html?book=Green&file=ULTRASONIC_FLOW_REF • http://www.aquametrix.com/data/dataDFM-IV.pdf • http://www.instrumentsdirect.com/technology/Ultrasonic-Doppler?gclid=CJvVstmY6IoCFQi8YAodeQq7mQ • http://ucce.ucdavis.edu/files/filelibrary/5049/640.pdf ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators

4. To explore further (survival pointers of web references etc) • http://www.nexsens.com/ • http://www.isa.org/InTechTemplate.cfm?Section=Article_Index1&template=/ContentManagement/ContentDisplay.cfm&ContentID=33182 ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators

5. Major applications • River and water way flow velocity measurement. • Oil and gas industry. • Water and wastewater treatment. • Food and beverage industry. http://pages.ripco.net/~jwn/rock.jpg http://www.alaskastock.com/Alaska_Pipeline_Photos.asp http://ga.water.usgs.gov/edu/pictures/wastewaterplant.jpg http://travel.webshots.com/photo/1076194657042961721DkGxiD ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators

6. Basic Working Principle Heard an ambulance go by recently? Remember how the siren's pitch changed as the vehicle raced towards, then away from you? First the pitch became higher, then lower. Originally discovered by the Austrian mathematician and physicist, Christian Doppler, this change in pitch results from a shift in the frequency of the sound waves, as illustrated in the picture on the right. ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators

7. Basic Working Principle (cont.) The basic principle behind ultrasonic Doppler flow sensors is this frequency shift, known as the Doppler Effect, of an ultrasonic wave as it is reflected by discontinuities in the fluid. ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators

8. Ultrasonic sound is transmitted across the fluid path. Discontinuities such as air bubbles or small solids reflect the sound waves with a slightly different frequency. This frequency shift is directly proportional to the rate of flow of the liquid. ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators

9. Basic Operation As illustrated in the figure on the previous slide, a typical system uses a transmitter and a transducer. The transducer, usually on the exterior of a pipe, is fed a high frequency signal from the transmitter. The transducer then transmits this signal through the wall of the pipe into the flowing liquid. The transmitter then measures the difference betweens its input and output signals converting this difference into electronic pulses which are then used to calculate the flow rate of the fluid. ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators

10. Typical Application Configuration Typical applications usually involve a network of flow sensors working together. A sensor network in this application results in much more accurate and reliable flow monitoring system. http://www.cidra.com/iss/technology/index.html http://www.cidra.com/iss/technology/index.html ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators

11. Major Specifications • Non-contacting. Sensor has no effect on actual fluid flow. • For most sensors, gas bubbles or solid particles in fluid must be larger than 100 microns in size and must be 75 ppm in concentration. • Piping cannot have air pockets. This means no concrete or wood piping. • Flow rate range: 0.25 to 40 ft/sec. • Power consumption: 12VDC, 100-130VAC, 50-60Hz, 5W max. • Temperature range: -10°F to 200°F ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators

12. Typical Sensor Examples Measure flow from outside a pipe. The Greyline DFM-IV is ideal for "difficult liquids" that would damage regular flow meters - wastewater, slurries, sludge, chemicals, viscous liquids and abrasives. There is no obstruction to flow and no pressure drop. The standard, strap-on ultrasonic sensor fits any pipe 1/2" (12.5 mm) Inside Diameter or larger. The electronics/display enclosure can be mounted nearby. http://www.aquametrix.com/prod_doppler.html Designed for mounting on the bottom of a river channel or lake, the Argonaut-XR is an advanced Doppler sonar for 3D water velocity measurement. Three-beam transducer for measuring 3D water velocity. Additionally, the Argonaut-XR never requires calibration and can reliably collect data up to 22 meters away from the sensor. All the electronics are housed in a low-profile (15cm) Delrin pressure case (200m max. depth) with base mounting plate. http://www.nexsens.com/products/sontek_1axr-20750.htm ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators

13. Limitations • Not suitable for clean liquids. Sensor requires air bubbles or particles in liquid in order to sense flow rate. • Cannot be installed on insulated piping. Insulation affects the ultrasonic signal. ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators

14. Cost • $795 for a basic clamp on flow sensor. • $4995 for a heavy duty portable flow sensor. • Prices can be closer to $10,000 for open-channel flow sensors. • Sensor rental is an option but still expensive. Typical rental of a portable sensor: $500 a week to $2000 a month. ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators

15. How to Pick the Right Sensor • Open-channel or pipeline. • How “dirty” is the liquid? Doppler flow sensors to not work well in clean and non-aerated fluids. • If application involves a pipeline, is the pipe insulted. Insulation has to be removed for sensor to operate. • Cost. As the previous slide shows Doppler flow sensors can be very expensive. ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators

16. How to pick the right sensor (cont.) • How close will the sensor be to a valve, tee, elbow, or a pump? Doppler flow sensors usually need a distance about 30 pipe diameters to measure the flow correctly. • Does the fluid have a high solid content? Doppler flow sensors lose accuracy if solid content more than 10% because the sound wave reflects off the slower water at the pipes side. • Sensor power. Do you need a sensor to run off 12VDC or 120VAC. Doppler sensors can be purchased either way. ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators

17. Where to Buy • Instruments Direct • Digi-key • GlobalSpec.com • Omega • Sensor can usually be purchased from the sensor manufacturer. Some sensors can only be purchased from the manufacturer. An example is the Argonaut-XR from NexSens Technology, Inc. ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators