Eclipse Model 700 Guided Wave Radar Level Transmitter

The Eclipse Model 700 Transmitter is a loop-powered, 24 VDC level transmitter that is based upon the proven and accepted technology of Guided Wave Radar (GWR).Encompassing a number of significant engineering accomplishments, this leading edge level transmitter is designed to provide measurement performance well beyond that of many of the more traditional technologies.


This single transmitter can be used in a wide variety of applications ranging from very light hydrocarbons to water-based media. One universal Model 700 transmitter can be used and interchanged with several different probe types and offers enhanced reliability as it is certified for use in critical SIL 2/3 hardware safety loops.The ECLIPSE Model 700 supports both the FDT/DTM and Enhanced DD (EDDL) standards, which allow viewing of valuable configuration and diagnostic information such as the echo curve in tools such as PACTware ™, AMS Device Manager, and various HART® Field Communicators.

Technology of Eclipse Model 700 Guided Wave Radar Level Transmitter 


ECLIPSE Guided Wave Radar is based upon the technology of TDR (Time Domain Reflectometry). TDR utilizes pulses of electromagnetic energy transmitted down a wave guide(probe). When a pulse reaches a surface that has a higher dielectric constant than the air (εr = 1) in which it is traveling, a portion of the pulse is reflected. The transit time of the pulse is then measured via high speed timing circuitry that provides an accurate measure of the liquid
(or solids) level. The amplitude of the reflection depends on the dielectric constant of the product. The higher thedielectric constant, the larger is the reflection.

Eclipse Model 700 overall


The ECLIPSE Model 700 is capable of measuring both an upper liquid level and an interface liquid level. As only a portion of the pulse is reflected from a low dielectric upper surface, some of the transmitted energy continues down the GWR probe through the upper liquid. The remaining initial pulse is again reflected when it reaches the higher dielectric lower liquid. It is required that the upper liquid has a dielectric constant less than 10, and the lower liquid
has a dielectric constant greater than 15. A typical interface application would be oil over water, with the upper layer of oil being non-conductive (εr ≈ 2.0), and the lower layer of water being very conductive (εr ≈ 80). The thickness of the upper layer could be as small as 2″ (50 mm) while the maximum upper layer is limited to the length of the GWR probe.

Eclipse Model 700 Interface level

Features of Eclipse Model 700 Guided Wave Radar Level Transmitter 

  • Multivariable, two-wire, 24 VDC loop-powered transmitter for level, interface, volume, or flow.
  • Level measurement not affected by changing media characteristics.
  • No need to move levels for calibration.
  • Overfill Capable probes allow for “true level” measurement all the way up to the process seal, without the need for special algorithms.
  • 4-button keypad and graphic LCD display allow for convenient viewing of configuration parameters and echo curve.
  • Proactive diagnostics advise not only what is wrong, but also offer troubleshooting tips
  • Nine common tank shapes for volumetric output.
  • 30-point custom strapping table for uncommonlyshaped tanks.
  • Two standard flumes and four standard weirs of various sizes for flow measurement.
  • Generic flow equation for non-standard channels.
  •  Probe designs up to +400 °F/6250 psi (+200 °C/431 bar).
  • Cryogenic applications down to -320 °F (-196 °C).
  • SIL certification allows use in SIL 2/3 Loops
  • No moving parts.

Application of Eclipse Model 700 Guided Wave Radar Level Transmitter 

MEDIA : Liquids, solids, or slurries; hydrocarbons to waterbased media (Dielectric Constant εr = 1.2–100)

VESSELS : Most process or storage vessels up to rated probe temperature and pressure.

CONDITIONS : All level measurement and control applications including process conditions exhibiting visible vapors, foam, surface agitation, bubbling or boiling, high fill/empty rates, low level and varying dielectric media or specific gravity.