D-1401 & D-1402 Portable Metering System Installation and Operation Guide • 03-17
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2.3
BASI C FLOW M EASUREM ENT
1. Turn the power switch (left) to “
ON”
position.
2. Set the middle switch to “
AVG”
and allow 45 seconds for the flow meter
circuitry to stabilize.
3. Record the average reading in Hz on the display and refer to the laminated
conversion chart to calculate the flow rate. Please note that the frequency
number displayed may vary rapidly (by as much as 10-15%) as a result of
the actual flow conditions in the pipe.
4. Locate the pipe size being measured on the laminated conversion chart and
determine the “ Z Factor” for gallons per minute (or liters per minute) for
that pipe size.
5. Then multiply the Z factor by the average reading in Hz from step 3 to
obtain the flow rate in gallons per minute.
2.4
FLOW PROFI LI NG M EASUREM ENT
D-1401 / D-1402 Systems:
Significant information about the nature of flow across the entire pipe diameter
can be obtained by taking flow measurements at incremental insertion depths.
Depending on the pipe size to be measured, determine an appropriate
measurement increment that will provide the required information. (For
example: when measuring the flow profile of an 8-inch pipe, measurements
may be made at 1 inch increments to provide the desired profile.)
With the flow meter properly inserted in the pipe, loosen the hot tap adaptor
lock nut and push the meter into the pipe until the end of the meter touches the
far pipe wall. Using this as a starting point, pull the meter back out by the
desired increment of measurement and measure the flow rate. Repeat this
process until readings have been made across the entire interior diameter of the
pipe.
In large pipes where the flow meter is not long enough to touch the far pipe
wall, measurements can be made using the near pipe wall as a starting point.
Push the flow meter into the pipe just until a flow reading is obtained on the
display. (For the
D-1402 systems, the top turbine output can be observed to see when it clears
the pipe wall and begins to spin.) Beginning at that point, start making
measurements at the desired incremental insertion depths.
D-1402 System Only: