||Thermal Wave Flowmeter for Measuring Combined Sewer Flows.
Eshlema, Paul W. ;
Blas, Robert A. ;
||Hydrospace-Challenger, Inc., Rockville, Md.
||DI-14-12-911; EPA-11020-EYD; R2-73-145;
Combined sewers ;
Thermal properties ;
Storm sewers ;
Integrated circuits ;
Sewage flow rate
||Some EPA libraries have a fiche copy filed under the call number shown.
A study of the application of thermal techniques to the measurement of flow rates in combined sewers has been conducted. The utilization of flush-mounted hot wire or hot film anemometers in a direct reading mode was extensively investigated. It was concluded that such a direct reading application was not feasible due to shifts in calibration caused by the build-up of contamination and the lack of commercially available units with sufficient ruggedness and reliability for application in a combined sewer pipe. A particular technique, which is based upon measuring the time-of-flight of thermal pulses generated at various positions around the perinphery of the pipe, was investigated in depth. A full scale prototype unit was fabricated and tested. These tests indicated that the configuration does not provide signals which have precision to enable the measure of fluid flow with the desired accuracy. (Author)