335

ECHOTEL ® N O N - C O N TA C T U LT R A S O U N D Non-Contact Ultrasonic Level Measurement N on-contact ultrasonic level technology is a proven method for accurate liquid level measurement. Process control instruments utilizing this technology sense and measure liquid level, volume, or open channel flow without making physical contact with the liquid itself. This offers distinct advantages over many contact technologies in applications where corrosive media, suspended solids, changing media characteristics, or coating media are present. Measuring with Ultrasound Two components make up a typical non-contact Ultrasound 101: ultrasonic measurement The Basics device: the transmitter, or electronics; and the transducer, or sensor. A piezoelectric crystal within the transducer converts electrical signals generated by the transmitter into a series of ultrasonic pulses. Under ideal conditions, these pulses are transmitted through free air at the speed of sound until they come into contact with the liquid surface where they are reflected back to the transducer. The transmitter’s electronics then measures the pulse’s roundtrip time and digitally processes the information to indicate liquid level. A transmitter programmed with a vessel’s geometry can calculate the liquid volume of a vessel. A transmitter programmed to convert the level reading into units of volume per time can measure the liquid flow rate in an open channel. Assuring Signal Integrity In the real world of process management, an ultrasonic signal launched into free air is vulnerable to distortion from many sources. Unless safeguards are taken by mechanical means or advanced signal processing, non-contact measurement can be greatly compromised. The most obvious form of interference are the physical structures inside of a vessel—pipes, ladders, struts, agitator blades, or irregular tank geometry. All of these can fall within the path of the ultrasonic beam to compromise the signal. The greater the distance from the transducer, the wider the beam spreads, thereby increasing the likelihood that a “false target” will enter the beam’s path. At 2 feet from the transducer, a typical ultrasonic beam may be less than 6 inches in diameter; but at 35 feet from the transducer The Transmitter houses the electronics for signal the conical shaped beam processing and control will expand to a diameter outputs. Depending on of 7 feet. the model, transmitters Magnetrol’s 335, 355, can be mounted either 344 and 345 transmitters integrally or remotely. have a False Target The Transducer is Rejection feature which located inside the filters out obstructions that vessel. It transmits and may lie within the path of receives the ultrasonic the beam. By entering the signals. locations of the obstructions into the transmitter’s false target memory, the user can program out the erroneous targets. As an additional measure to assure instrument integrity, Magnetrol transmitters feature a selfdiagnostics capability which continuously checks all relays, outputs and the overall function of the transducer and electronics. Ambient temperature can also have a significant effect on the accuracy of a non-contact ultrasonic transmitter. As temperature decreases, air becomes 2 more dense, resulting in slower sound velocity. Since measurement is directly dependent on sound speed, it is necessary to compensate for temperature changes. All Magnetrol’s transducers include a temperature compensation circuit which continuously monitors the temperature at the sensor and compensates for variations over the full temperature range of the transducer. Ultrasonic non-contact devices are typically rated for a maximum range in ideal conditions. But process conditions can impact the maximum range of measurement. These conditions include surface agitation, vapors and steam, foam and air movement. A derating multiplier can be computed to yield a new maximum range for optimum performance. A lower frequency transducer, such as the 38 kHz model, provides increased power with a longer wavelength to increase measurement range and improve performance where steam, vapors or turbulence may be present. Technology Advantages and Limitations The advantages of non-contact sensing are: • No contact with corrosive, contaminating liquids. • Accurate to within 0.25% of measured span. • Continuous and multiple-point sensing available. • No moving parts for reduced maintenance. • Not affected by changes in liquid properties such as specific gravity, dielectric shifts, pH, etc. • Intrinsically safe, non-incendive and explosion proof instruments are available. Conditions limiting ultrasound’s effectiveness include: • Surface foam that absorbs the ultrasonic signal. • Vapors that significantly alter the speed of sound. • Operating pressures exceeding 50 psig (3.45 bar). • Temperatures exceeding +200° F (+93° C). I Real World Applications Echotel non-contact ultrasonic transmitters have been engineered to meet the process requirements of major industries including: Oil & Gas, Chemicals, Food & Beverage, Power Generation, Pulp and Paper, Water & Wastewater, Pharmaceutical, and Petrochemical. Chemical Feed Tanks Clarifier Level Influent/Effluent Flow Fuel Oil Storage Condensate Storage Open Atmosphere Sumps 3 NON-CONTACT ULTRASOUND 300/301 L Advanced Electronics For Liquid Level, Volume or Open Channel Flow Available as an integral or remote mounted unit, this versatile and powerful ultrasonic transmitter is easy to install and quick to calibrate. Isolated 4–20 mA output with an active/passive mode for loop power or device power. RS-485 with Modbus protocol allows bi-directional communication with DCS or PLC. Two or four 10 amp SPDT gold flash relays for a wide variety of alarm and control schemes. L Explosion-Proof Transmitter and Transducer The Model 300/301 has Explosion-Proof FM and CSA agency approvals for both the transducer and the transmitter: Class I, Division 1, Groups B, C, and D. L Model 300/301 A 16-button keypad and two-line, 16-character LCD display is inside the explosion-proof housing Model 300/301 Transmitter Specifications Power Supply Fast, Password-Protected Calibration Unique QuickCal™ calibration feature allows complete system calibration in 90 seconds. A password protection feature also prevents unwanted tampering with the configuration data. Transducer Specifications Frequency Beam Angle Max Range/Span Dead Zone Process Temp Process Pressure Cable Length 38 kHz Conical 12° 30 feet (9.1 m) / 28.5 feet (8.7 m) 18 inches (460 mm) minimum -40° to +163° F (-40° to +73° C) Atmospheric to 50 psig (3.45 bar) 500 feet maximum 120 VAC ±10%, 50-60 Hz 240 VAC ±10%, 50-60 Hz 24 VDC ±20% Power Consumption Analog Output Signal 12 watts maximum 1,000 Ω loop resistance Active Mode 4–20 mA (isolated); maximum of Passive Mode 4–20 mA (isolated); loop resistance dependent on power supply (32 volt max) 1,000 Ω @ 24 volts Applications Digital Output Relays Fail-safe Ambient Temperature Electronics Display Keypad Response Time Accuracy RS-485 with Modbus 10 amp SPDT resistive (0, 2 or 4) User selectable for analog and relay outputs -40° to +160° F (-40° to +71° C) Two-line, 32 character LCD 16-button (inside housing) 2 seconds, typical ±0.25% of calibrated span • Viscous Fluids • Acids, Caustics • Water & Wastewater • Chemicals • Pulp & Paper • Power Generation 4 NON-CONTACT ULTRASOUND 335 L For Liquid Level, Volume or Open Channel Flow With flexible software, advanced signal processing and a powerful transducer, the Model 335 offers outstanding measurement performance and value. Hinged, Dual Compartments The LCD module compartment houses the user interface and the lower compartment houses the wiring terminals. A screw release allows the LCD compartment to swing completely clear of the wiring module. L View of LCD Plug-In Display Module L 335 Electronics Advanced digital signal processing provides optimum performance in a variety of process conditions. Echotel 335 Transmitter Specifications Power Supply Output Signal Fault Detection Relay Fail-safe Ambient Temperature Display Keypad LED Status Indication Compensation Accuracy Enclosure Protection 4–20 mA (isolated); 600 Ω load 85 to 255 VAC LED, and 3.6 or 22 mA One, 3-amp SPDT Software selectable -22° to +140° F (-30° to +60° C) Removable six-digit LCD module with dual function bar graph 4-button menu-driven data entry Echo strength, power, relay LED’s Auto temperature compensation over transducer operating range ±0.2% of measured distance, plus 0.05% of the range Dual compartment cast aluminum NEMA 6 (IP 67) Transducer Specifications Frequency Beam Angle Max Range Dead Zone Process Temp Process Pressure Material Protection Applications 50 kHz Conical 7° 26 feet (8 m) 14 inches (350 mm) -22° to +195° F (-30° to +90° C) Atmospheric to 44 psig (3 bar) Polypropylene NEMA 6P (IP68) Configurable 3 amp SPDT relay, • Sump, Well, & Tank Level • Open Channel Flow • Water & Wastewater Treatment • Chemical Storage Tanks • Food & Beverage Containers • Pulp & Paper Vessels 5 L The module offers easy set-up and configuration of all process parameters via four push buttons. The custom graphics LCD displays six-characters and a bar graph of signal strength or tank level. The module can be removed to configure other 335 units. module through housing cover window Enlarged view of LCD module in working unit L L LCD module removed NON-CONTACT ULTRASOUND 344/345 For Liquid Level, Volume or Open Channel Flow A remote mounted, full-featured ultrasonic transmitter with extensive agency approvals. Many transducer configurations and transmitter options are available for greater versatility. L Convenient Front Panel Interface Front panel keypad makes programming convenient; once wired, there’s no need to open the enclosure. A large, 16-character alphanumeric display shows all parameters and a password code prevents unauthorized tampering with configuration data. L Choice of Transducers The Model 344 employs the powerful 38 kHz Kynar transducer used primarily for level and volume applications. The Model 345 uses the 50 kHz transducer, available either in Kynar or 316 stainless steel. Transducers feature temperature compensation. L Transducer Outputs Temperature System Full-Featured Electronics Automatic, continuous self-test checks transducer signal, temperature sensor, all outputs and system functionality for proper operation. False target buffering feature eliminates signal interference for up to nine fixed tank obstructions. Model 344/345 Transmitter Specifications Power Supply 120 VAC ±10%, 50-60 Hz 240 VAC ±10%, 50-60 Hz 24 VDC ±20% Power Consumption Output Signal Relays Fail-safe Display Keypad Response Time Accuracy Ambient Temperature with Heater & Thermostat -40° to +160° F (-40° to +70° C) w/o Heater & Thermostat -4° to +160° F (-20° to +70° C) Agency Approvals Class I, Division 2, Non-incendive and NEMA 4X from FM and CSA 12 watts (without heater) 4–20 mA isolated (1,000 Ω load), Transducer Specifications Frequency Max Range Max Span Process Temp Process Pressure Beam Angle Cable Length Applications 38 kHz 35 feet (10.7 m) 33.5 feet (10.2 m) -40° to +163° F (-40° to +73° C) 50 kHz 25 feet (7.6 m) 24 feet (7.3 m) -40° to +200° F (-40° to +93° C) RS-232 (data logger downloading) Four, 10-amp resistive, SPDT User selectable for analog and relay outputs 16-character alphanumeric 16-button integral to front panel 2 seconds, typical ±0.25% of configured span Atmospheric to 50 psig (3.45 bar) Conical 12° 500 feet maximum • Sump & Wastewater • Slurries, Viscous Fluids • Pulp & Paper • Power Generation • Petrochem 6 NON-CONTACT ULTRASOUND 355 L L For Liquid Level, Volume or Open Channel Flow Outstanding measurement performance and value in a two-wire, integral transmitter featuring flexible software and advanced signal processing. Temperature Compensated Echo Rejection The Model 355 has a patent-pending echo rejection technique that constantly adjusts the rejected echo profile based on the current sound propagation velocity. This technique keeps the transmitter tracking the actual liquid level as opposed to false targets even when temperature changes alter the shape of the echo rejection profile. L Model 355 Transmitter Specifications Power Supply Power Consumption Output Signal Fault Detection Damping Ambient Temperature Display Keypad Compensation Accuracy Repeatability Resolution Linearity Response Time Warm-up Time Enclosure Protection 16 to 36 VDC Less than 1 Watt 4–20 mA with optional HART Adjustable from 1–60 2-line × 16-character LCD -40° to +175° F (-40° to 80° C) ® Dual Flow Totalizers Two 7-digit flow totalizers are provided for recording flow. One totalizer is resettable and the other is non-resettable. Several multipliers are selectable to allow for proper scaling. Totalizer time is also recorded to show how long each totalizer has been recording flow. Stored Tank Shapes for Volume Volume configuration with the 355 is as easy as selecting the tank shape and inputting 1–3 dimensions. While a 20-point custom table is also available, selecting the actual tank shape provides for a fast and accurate configuration for a variety of common tank shapes. Transducer Specifications Frequency Beam Angle Max Range Blocking Distance Process Temp Process Pressure Material Protection Applications 60 kHz Conical 10° 20 feet (6 meters) 10 inches (250 mm) -40° to +175° F (-40° to +80° C) 0 to 43.5 psig (0 to 3 bar) Kynar® Flex (PVDF) or polypropylene NEMA 6P (IP 68) Selectable from 3.6, 22 mA, or hold 4-push-button menu-driven Auto temperature compensation over transducer operating range Greater of ±0.2% of range or 0.24 inch (6 mm) ±0.125 inch (3 mm) 0.1 inch (2.5 mm) ±0.4 inch (10 mm) Less than 1 second (typical) 30 seconds Cast aluminum or Lexan NEMA 6 (IP 67) ® • Sump, Well, Tank Level • Highly Viscous Media • Paint, Ink & Solvents • Food & Beverage Vessels • Batch & Day Tanks 7 CORPORATE HEADQUARTERS 5300 Belmont Road • Downers Grove, Illinois 60515-4499 USA Phone: 630-969-4000 • Fax: 630-969-9489 www.magnetrol.com • info@magnetrol.com EUROPEAN HEADQUARTERS Heikensstraat 6 • 9240 Zele, Belgium Phone: 052 45.11.11 • Fax: 052 45.09.93 BRAZIL: Av. Dr. Mauro Lindemberg Monteiro • 185-Jd. Santa Fé, Osasco • São Paulo CEP 06278-010 CANADA: 145 Jardin Drive, Units 1 & 2 • Concord, Ontario L4K 1X7 CHINA: Plant 6, No. 191, Huajin Road • Minhang District • Shanghai 201109 DEUTSCHLAND: Alte Ziegelei 2–4 • D-51491 Overath DUBAI: DAFZA Office 5AE 722, P.O. Box 293671 • Dubai, United Arab Emirates INDIA: C-20 Community Centre • Janakpuri, New Delhi 110 058 ITALIA: Via Arese, 12 • 20159 Milano SINGAPORE: 33 Ubi Avenue 3 • #05-10 Vertex • Singapore 408868 UNITED KINGDOM: Regent Business Centre • Jubilee Road • Burgess Hill, West Sussex RH15 9TL Copyright © 2010 Magnetrol International. All rights reserved. Printed in the USA. Echotel® Magnetrol® and the Magnetrol logotype are trademarks of Magnetrol International. Kynar® is a trademark of The Pennwalt Corporation. Bulletin: 51-180.3 • Effective: July 2009