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Frazier Engineering Getting Better Flow Data with Hach FL900AV

When new flow monitoring equipment was required to update Frazier Engineering’s fleet, they selected Hach FL900 Series Flow Loggers. A long-time user of Hach’s Sigma flow meters, Frazier Engineering, is a civil engineering firm that serves customers in the Carolinas, Virginia and Tennessee. They have over 18 years experience in collection system flow monitoring. In addition to flow monitoring services, Frazier provides sewer system planning/design and sanitary sewer rehabilitation redesign.

According to Mark Lambert, Project Manager for Frazier, "When some of our oldest Sigma meters required extensive repairs, we made the decision to replace them with FL900AV Flow Loggers. So far we have purchased 25 new flow loggers to replace Sigma Models 920 and 930 meters." The new loggers will be used in pipe sizes ranging from 8 to 48 inches. Lambert has been in the flow business for 23 years including roles as both a consultant and municipal employee. He states that their clients’ flow monitoring projects can range from 1 to 70 meters with an average of 25 meters. Lambert feels that Frazier Engineering’s flow business has grown for a number of reasons, including flow monitoring expertise, flow meter repair capabilities, and extensive data interpretation and site selection experience. He adds, "There are so many things that can go wrong in flow monitoring, and our customers rely on us for our expertise."

frazier1 Newly purchased Sigma AV Sensors, as well as existing Sigma AV sensors in their stock, were used with the new loggers. Their existing flow meter fleet is comprised of 78% Sigma/Hach flow meter systems and is a mix of both wireless and non-wireless Sigma AV and FLO-DAR AV sensors. Client flow meters are installed and maintained by Frazier Engineering field crews, whom Lambert praises for their ability to quickly get up to speed on new flow monitoring hardware and software.

The Hach FL900AV Flow Meter was designed for users desiring in-depth analysis and custom settings. The diagnostic tools and advanced architecture in the Hach FL900AV Flow Meter with AV9000 Analyzer Module make it possible to acquire useful flow data in even the most difficult sites. This powerful meter provides "cleaner," more precise data than ever before with advanced signal processing and filtering options, expanding the applicability of submerged AV sensors into more difficult applications. The AV9000 Area Velocity Analyzer module is compensated for temperature, thus eliminating potential velocity errors that occur during seasonal temperature changes. Its advanced multi-scale digital Doppler analysis provides the optimal combination of resolution and noise immunity. Mirror Image Processing™ eliminates sign errors and the advanced Target Set Processing™ reduces the impact of dominant targets (particles) in the stream to deliver a more representative velocity. FLO-WARE Data Management Software is compatible with the system as well as FSDATA Online Data Manager website for wireless applications.

Additional FL900AV Flow Meter Features

  • On-site verification of flow meter performance using advanced diagnostics
  • Step-by-step calibration guides for easy and precise set ups
  • Advanced signal processing and filtering options reduce noise in difficult applications
  • Dynamic logging intervals automatically enables the delivery of greater resolution flow data during high flow periods and battery/data volume conservation during low-flow seasons

frazierOne of Frazier’s clients with newly installed FL900AV loggers is the Water and Sewer Authority of Cabarrus County (WSACC) located in Concord, NC. Some of the meters used in this application are master billing meters. Lambert states, "In the past we had problems with the old Sigma 920 and 930 meters in one of their low flow sites. They just weren’t giving good data. After installation of the new Hach FL900AV flow meter in the same low flow site the data is so much better.” We are seeing a much better diurnal pattern and the sensors don’t seem to drift." With regard to other sites where new Hach FL900AV loggers are installed, Lambert claims that overall he is just seeing much better data. To date, WSACC has purchased 18 FL900AV’s with plans to buy 12 more to replace their older Sigma 920 and 930 flow meters..

Lambert enjoys the loggers wireless option and the ability to see the data in real-time on the FSDATA Online Data Manager website. He finds it helpful to be able to visit the website to check on meter operation. Frazier’s flow clients are also provided access to the website to view their flow data for their own specific needs. The FSDATA graph below shows data from a low flow site at the Water and Sewer Authority of Cabarrus County that had been difficult to monitor before the use of the FL900AV flow meter. As seen in this application with the FL900AV flow meter, more accurate data produces more accurate billing.


Going forward, Lambert knows several of his clients will be replacing their Sigma meters with Hach FL900AV flow meters in the near future. He adds, "Compared with the old Sigma meters, the technology is obviously better and I have definitely seen an improvement."

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