H O R I Z O N G U I D E D W A V E R A D A R

Transcription

1 H O R I Z O N G U I D E D W A V E R A D A R

2 An Introduction To Horizon Guided Wave Radar H orizon transmitters utilize Guided Wave Radar (GWR) technology for unsurpassed accuracy and reliability in monitoring liquid levels. Alhough GWR technology was first employed for the detection of underground cable breaks as early as the 1930s, Magnetrol Pulses Generated Horizon transmitters generate pulses of electromagnetic energy that are transmitted down the probe, or waveguide. HOW GUIDED WAVE RADAR WORKS Pulses Reflected When they reach a liquid surface that has a higher dielectric than the air or vapor in which they travel, the pulses are reflected. Time converted to Distance The pulses transit time is measured, converted to distance, and can be displayed on the LCD as a level reading. pioneered its use for liquid level measurement with the introduction of the Eclipse Model 705 transmitter in No other level measurement technology has captured the attention of the process control industry the way ECLIPSE has in the short time since its introduction. In 2003, the HORIZON transmitter was introduced to bring economical, general purpose guided wave radar transmitters to the industries we serve. Principle of Operation Guided Wave Radar functions according to the principles of Time Domain Reflectometry (TDR) and Equivalent Time Sampling (ETS). As shown at left, a generated pulse of electromagnetic energy travels down the probe. Upon reaching the liquid surface the pulse is reflected. ETS captures these signals in real time (nanoseconds) and reconstructs them in equivalent time (milliseconds) to make level measurement a practical reality. Unlike conventional radar, which launches its signal into free space, HORIZON launches its signals within the focused path of its probe (wave guide) which is in direct contact with the process media. This direct contact makes the signal less vulnerable to distortion brought on by process conditions that might thwart through-air technologies. HORIZON transmitters have been designed to bring affordable Guided Wave Radar level measurement to the process industry. The Model 704 features the ability to configure the transmitter without a change in level. The Model 704 also offers an easy to read two-line by eight-character LCD, optional HART communications, and an adjustable diagnostic alarm. 2

3 Horizon Transmitters Affordable Guided Wave Guided Wave Radar has demonstrated an ability to provide accurate and repeatable measurement at a performance level that surpasses many traditional technologies. This is due to the efficiency of Guided Wave Radar technology and to the MAGNETROL wide range of sensing probes designed to meet the process variables discussed ahead. HORIZON accurately measures liquids and slurries with a dielectric range of 1.7 to 100 from hydrocarbons to water-based media. The transmitters perform in all conventional HORIZON transmitters are designed to work in applications in petroleum refining, chemical manufacturing, water & wastewater, pulp & paper, and food & beverage. HORIZON transmitters also serve as ideal retrofit transmitters made possible by the MAGNETROL wide range of adaptation hardware for easy and affordable replacement of outdated level measurement technology. HORIZON transmitters have been engineered to provide users with the basic range of measurement solutions in Guided Wave Radar. HORIZON has emerged as the affordable alternative in Guided Wave process and storage vessels, bridles Process Connected Radar measurement for today s liquid level and bypass chambers whose temperatures and pressures are rated to the transmitted via the wave- Because the Guided challenges. Wave Radar signal is capabilities of the particular probe used. guide directly into the process media, it is not HORIZON transmitters offer sensor distorted by tank atmospheres, process condi- probes for routine storage vessels as tions, tank obstructions, well as those exhibiting corrosive or false echoes. vapors, foam, surface agitation, high fill/empty rates, low level, and varying dielectric or specific gravity. HORIZON 704 The HORIZON Model 704 is an intermediate transmitter which utilizes coaxial and twin rod probes. 3

4 M O D E L G E N E R A L S P E C I F I C A T I O N S ➀ Transmitters for Process-Specific Measured Variable Liquid level Solutions Signal Output 4 20 ma or 4 20 ma with HART 3.8 to 20.5 ma useable (meets NAMUR NE 43) Span 6 to 192 inches (15 to 488 cm) Resolution Analog: 0.01 ma Digital: 0.15 inch Loop Resistance VDC (20.5 ma) Damping Adjustable 0 10 seconds Diagnostic Alarm Adjustable 3.6 ma, 22 ma, HOLD User Interface 3-button keypad and/or HART communications (optional) Display 2-line 8-character LCD Power (at terminals) 12 to 28.6 VDC Menu Language English, German, French or Spanish Housing Material Aluminum A356T6 (<.25% copper) Valox, UL94-V0 rating Net and Gross Weight Aluminum: 3.5 lbs. ( 1.59 kgs) / Plastic: 1.5 lbs. (.68 kgs) Overall Dimensions H 6.5" W 4.5" (H 165 mm W 114 mm) ➀ Consult the HORIZON product bulletin (57-104) for specific hazardous location approvals. M O D E L P E R F O R M A N C E S P E C I F I C A T I O N S Reference Conditions Reflection from liquid at +70 F (+20 C) with a 72" probe Probes 7XA, 7XB, 7XP, 7XR Linearity 7XA, 7XP, 7XR Probe: ±0.25 inch (6.3 mm) 7XB Probe: ±0.50 inch (12.7 mm) Resolution ±0.15 inch (4 mm) Repeatability 0.15 inch (4 mm) Hysteresis 0.15 inch (4 mm) Warm-up Time < 5 seconds Operating Temperature Range Aluminum Housing: -40 to +175 F (-40 to +80 C) Plastic Housing: -40 to +160 F (-40 to +70 C) LCD Temperature Range -5 to +160 F (-20 to +70 C) Operating Temperature Effect Approximately ±0.03% of probe length/ C Process Dielectric Effect < 0.5 inch (12.7 mm) Humidity 0 99%, non-condensing Electromagnetic Compatibility Meets CE requirements (EN , EN ) (Twin Rod probes must be used in metallic vessel or stillwell to maintain CE requirement) 4

5 P R O B E O V E R V I E W Choosing the proper Guided Wave Radar (GWR) probe is the most important decision in the application process. The probe configuration establishes fundamental performance characteristics. Coaxial, twin element (rod or cable) and single element (rod or cable) are the three basic configurations used today; each with specific strengths and weaknesses. C O A X I A L P R O B E S The Coaxial probe is the most efficient of all probe configurations and should be the first consideration in all applications. Analogous to the efficiency of modern, coaxial cable, coaxial probes allow almost unimpeded movement of the high frequency pulses throughout its length. Figure 1 Coaxial Probe The electromagnetic field that develops between the inner rod and outer tube is completely contained. See Figure 1. The efficiency and sensitivity of a coaxial configuration yields robust signal strength even in extremely low dielectric (ε r > 1.7) applications. The sensitivity of this closed design, however, also makes it more susceptible to measurement error in applications of coating and buildup. T W I N R O D P R O B E S The relationship of the twin rod probe to a coaxial is similar to that of older, twin-lead, antenna lead-in to modern, coaxial cable. The 300-ohm twin-lead cable simply does not have the efficiency of the 75-ohm coax. The parallel conductor design is less sensitive than the concentric coaxial. See Figure 2. This translates to Twin Rod GWR probes measuring dielectrics of only ε r > 2.5. The open design also allows more accurate measurement where coating/ buildup are possible. A film coating has little effect on performance. However, bridging of material between the rods or buildup on the spacers can cause improper measurement and should be avoided. Figure 2 also shows that the electromagnetic field develops not only between the rods, but also expands outward making it more sensitive to proximity effects of objects located in the immediate area. Figure 2 Twin Rod Probe N O Z Z L E S The 7XB Twin Rod probe may be susceptible to objects that are in close proximity. The following rules should be followed for proper application: A Figure 3 B 1. Nozzle should be 3" (80 mm) diameter or larger. 2. For nozzles < 3" (80 mm) diameter, the bottom of the inactive section of the probe should be flush with the bottom of the nozzle or extend into the vessel. O B S T R U C T I O N S ( M E T A L L I C ) 7XB Twin Rod probes should be installed so the active rod (below the 4" (100 mm) inactive sheath) is > 1" (25 mm) from metallic objects such as pipes, ladders, etc. Bare tank walls parallel to the probe are acceptable. T U R B U L E N C E The bottom of the probe should be stabilized if turbulence will cause a deflection of more than 3" (80 mm) at 10' (3 m) of length. The probe should not make contact with a metal tank. 5

6 7XA STANDARD COAXIAL 7XB STANDARD TWIN ROD Coaxial design is the most efficient probe in the guided wave radar line Recommended for general purpose applications with clean, low-viscosity liquids Suitable for media with dielectric as low as 1.7 FM, CSA and ATEX safety approvals A general purpose probe recommended for higher viscosity applications of up to 1500 cp Buildup of thick or dirty media on the probe is well managed by the twin rod design Available in threaded or flanged connections For dielectric 2.5 Model 7XA Standard Coaxial Probe Materials/Wetted Parts 316/316L SS (Hastelloy C and Monel optional), TFE spacers, Viton O-rings Diameter.3125" (8 mm) rod.875" (22 mm) tube Process Connection 3 4" NPT and 1" BSP (Various ANSI or DIN flanges) Length 24 to 192 inches (60 to 488 cm) Transition Zone Top: 1" ε r = 1.4; 6" ε r = 80 Bottom: 6" ε r = 1.4; 1" ε r = 80 Max. Process Temp psig ( bar) Max. Process Pressure F ( C) Max. Viscosity 500 cp Dielectric Range 1.7 Mounting Effects None Media Coating Not recommended 6 Model 7XB Standard Twin Rod Probe Materials/Wetted Parts 316/316L SS (Hastelloy C and Monel optional), TFE spacers, Viton GFLT O-rings Diameter Two.5" (13 mm) rods.875" (22 mm) C L to C L Process Connection 2" NPT (Various ANSI or DIN flanges) Length 24 to 192 inches (60 to 488 cm) Transition Zone Top: 8" (+4" inactive) ε r 2.0 Bottom: 6" ε r = 2.0; 1" ε r = 80 Max. Process Temp psig ( bar) Max. Process Pressure F ( C) Max. Viscosity 1500 cp Dielectric Range 2.5 Mounting Effects Active Rod > 1" from any surface or obstruction Media Coating Film: 3% max. error of coated length with conductive media Bridging: Not recommended

7 7XP HIGH PRESSURE 7XR OVERFILL Recommended for clean, high-pressure liquids without high temperatures Withstands pressures of up to F (345 bar at +20 C) High-integrity seal design withstands toxic media and fugitive emissions Suitable for full-vacuum applications Enlarged version capable of handling viscosities up to 1500 cp Provides accurate measurement to the 100% full point of a tank or chamber. Level can be accurately and repeatedly measured to the very top of the vessel No transition zone. Recommended for clean, low viscosity liquids Suitable for media with a dielectric as low as 1.4 Enlarged version capable of handling viscosities up to 1500 cp Model 7XP High Pressure Coaxial Probe Model 7XR Overfill Coaxial Probe Materials/Wetted Parts 316/316L SS, Inconel X750, Borosilicate seal, TFE spacers Materials/Wetted Parts 316/316L SS (Hastelloy C and Monel optional), TFE spacers, Diameter: Standard.3125" (8 mm) rod Viton GFLT O-rings.875" (22 mm) tube Diameter: Standard.3125" (8 mm) rod Enlarged.60" (15 mm) rod.875" (22 mm) tube 1.75" (44 mm) tube Enlarged.60" (15 mm) rod Process Connection 3 4" NPT and 1" BSP 1.75" (44 mm) tube (Various ANSI or DIN flanges) Process Connection 3 4" NPT and 1" BSP Length 24 to 240 inches (60 to 610 cm) (Various ANSI or DIN flanges) Transition Zone Top: 1" ε r = 1.7; 6" ε r = 80 Bottom: 6" ε r = 1.7; 1" ε r = 80 Length Transition Zone 24 to 240 inches (60 to 610 cm) Top: Not applicable Max. Process Temp psig ( bar) Max. Process Temp. Bottom: 6" ε r = 1.4; 1" ε r = psig Max. Process Pressure F ( C) Max. Process Pressure ( bar) F Max. Viscosity 500 cp ( C) Dielectric Range 1.4 Max. Viscosity 500 cp Mounting Effects None Dielectric Range 1.4 Media Coating Not recommended Mounting Effects None Hermeticity Helium leak rate < atmosphere Media Coating Not recommended 7

8 CORPORATE HEADQUARTERS 705 Enterprise Street Aurora, Illinois USA Phone: Fax: magnetrol.com EUROPEAN HEADQUARTERS Heikensstraat Zele, Belgium Phone: Fax: BRAZIL: Av. Dr. Mauro Lindemberg Monteiro, 185, Quadrante 16 CEP Osasco São Paulo CANADA: 145 Jardin Drive, Units 1 & 2 Concord, Ontario L4K 1X7 CHINA: Plant 6, No. 191, Huajin Road Minhang District Shanghai DEUTSCHLAND: Alte Ziegelei 2 4 D Overath DUBAI: DAFZA Office 5EA 722, P.O. Box Dubai, United Arab Emirates INDIA: C-20 Community Centre Janakpuri, New Delhi ITALIA: Via Arese, Milano SINGAPORE: 33 Ubi Avenue 3 #05-10 Vertex Singapore UNITED KINGDOM: Regent Business Centre Jubilee Road Burgess Hill, West Sussex RH15 9TL Magnetrol, Magnetrol logotype, Eclipse and Horizon are trademarks of Magnetrol International, Incorporated. Viton is a registered trademark of DuPont Performance Elastomers. Teflon is a registered trademark of DuPont. Hastelloy is a registered trademark of Haynes International, Inc. Monel is a registered trademark of Special Metals Corporation. Tri-Clover is a registered trademark of Tri-Clover, Inc. Copyright 2012 Magnetrol International, Incorporated. All rights reserved. Printed in the USA. Bulletin: Effective: September 2010