Measurement of liquid level can be very challenging, especially in water and wastewater applications and mechanical
instrumentation is still widely used as a bedrock of level control in this market. Over time, mechanical products
have given way to newer technologies and the municipal market place has witnessed its fare share of technologies that
have fundamentally altered how measurements are being taken in water and wastewater applications.
These newer technologies were hailed, in their time, as ushering in a new era in measurement and performance with their
ability to solve application problems, which historically have been solved with more tried and true methods. These
technologies offered improved accuracy and reliability without the
complexity, cost, and maintenance of mechanical operating systems. What became apparent as these electronic
technologies were successfully put into service, was they were sometimes installed in marginal applications
since a better solution didnƒÿt exist. Many ended up having significant application sensitivities that could
be problematic to live with and result in a higher TCO (total cost of ownership). The problematic nature of
these electronic measurement devices has spurred development of newer and better ways to solve application problems.
A technology that has made its presence known in the industrial market place for many years is now starting to be
recognized as a viable alternative to many of the technologies listed above. Radar transmitters hold great promise
for the municipal marketplace, but is radar the "be all and end all" level
measurement technology; the answer to all level measurement applications? We'll examine that question and many
others as we consider the application of radar technology to municipal applications.
This paper will examine the use of new radar technology, both through air radar and guided wave radar upon
applications in the Water and Wastewater industry. We will consider the technical nature of both Through
Air Radar (TAR) and Guided Wave Radar (GWR). We will continue with application and installation considerations,
including the three "D's" of radar, along with other process and physical installation parameters that
are critical in the successful application of radar. We will examine the physical nature of both TAR and GWR
and advantages and disadvantages over other level measurement technologies.
