Guided Wave Radar
Eclipse Enhanced 705
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  The Enhanced Eclipse Model 705 is a 24 VDC loop-powered level transmitter based upon the revolutionary Guided Wave Radar (GWR) technology. This single transmitter can be used with all probe types and offers enhanced reliability, as demonstrated by a Safe Failure Fraction of 91%, allowing it to be used in SIL 2 loops. This Eclipse transmitter is designed to provide measurement performance well beyond that of many traditional technologies. The innovative, patented enclosure is a first in the industry orienting both wiring and electronics compartments in the same plane; and, angled to maximize ease of wiring, configuration and data display. Eclipse supports the FDT/DTM standard and a PACTware™ PC software package allows for additional configuration and troubleshooting flexibility |
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Coaxial Probes
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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. The electromagnetic field that develops between the inner rod and outer tube is completely contained. The efficiency and sensitivity of a coaxial configuration yields robust signal strength even in extremely low dielectric (ƒÃr .1.4) applications. The sensitivity of this "closed" design, however, also makes it more susceptible to measurement error in applications of coating and buildup. |
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Twin Rod Probes
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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. 300 ohm twin-lead cable simply does not have the efficiency of 75-ohm coax. The parallel conductor design is less sensitive than the concentric coaxial. This translates to Twin Rod GWR probes measuring dielectrics of only ƒÃr .1.9. The "open" design also allows more accurate measurement where coating/buildup is 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. With a twin-rod probe the electromagnetic field develops not only between the rods, it also expands outward making it more sensitive to proximity effects of objects located immediately around it. |
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Single Rod Probes
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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. Single element GWR probes act quite differently from Coaxial and Twin element designs. The pulses of energy develop between the center rod and the mounting nut or flange; the pulse propagates down the rod as it references its ground at the top of the tank. The efficiency of the pulse "launch" is directly related to how much metallic surface exists around it at the top of the vessel. Signal transmission can be significantly improved by placing a single rod inside of a bridle or chamber. |
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