FLOW METER SELECTION/INSTALLATION
Once a site has been identified the appropriate meter with any specific sensors will be installed.
The installation will consist of installing tight fitting aluminum bands with both flow depth and
velocity sensors mounted in such a way as not to obstruct flow or snag paper or other disposed
items m the flow stream.
INITIAL & SUBSEQUENT FLOW VERIFICATION
During the installation process, the meter will be operated in such a way as to instantaneously
obtain and display both depth and velocity readings. Manual depth measurements will be
obtained and compared to meter readings, any diffizrences will be corrected to within 0.10
inches. Using a hand held velocity meter, readings will be obtained and compared to the metered
velocity readings and adjustments to the installed equipment will be made until a reasonable
match is obtained. During each maintenance Visit, the following will be performed and noted on
site log sheets:
Actual depth of flow
Metered depth of flow
Actual flow velocity
Metered flow velocity
Flow pattern will be graphed for the previous period
Scatter plots of both depth & velocity will be reviewed
Any adjustments ( if necessary) will be noted
Battery voltage logged and if necessary, batteries will be replaced
DATA QUALITY REVIEW
Staff operating at our headquarters will review the flow data as it is received for completeness
(missing data). A more detailed review will take place at a later date when the actual field logs
arrive. Flow data files will then be combined with rainfall data and graphs will be prepared to
begin a more detailed review of all depth, velocity and flow data. Abnormalities such as
unexplainable depth spikes or drop outs as well as inconsistent velocity trends will be noted.
Additional comparison graphs will be prepared that will use both actual depth and velocity data
as well as predicted data. Scatter plots will also be produced to better understand specific
characteristics of the site as well as help identify isolated incorrect measurements. Adjustments
or corrections, if any, will be performed and documented.
IV. CLIENT RESPONSIBILITIES
The Client shall provide the following at no additional cost to the Subconsultant:
A. Furnish copies of the necessary plot maps of all sewers to be studied. The sewer lines and
manholes should be clearly marked and labeled with a numbered refierence system.
B, Make any revisions to the sewer maps in the study area based on correction data collected
during the fieldwork.
C. Make arrangements to provide traffic control as required by local public safety authorities.
