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Furrow flow measurement accuracy

Trout, Thomas J. and Mackey, Bruce E. (1988) Furrow flow measurement accuracy. Journal of Irrigation and Drainage Engineering. 114(2):244-255.

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The primary source of error in properly calibrated, constructed,
and installed flow measurement devices is due to reading error
or uncertainty. Head reading uncertainty in small V-notch flumes and
submerged orifices is measured in the field as ±3mm with no consistent
variation with reading. Elapsed time measurement uncertainty for
volumetric measurements increases with the square root of the time.
The sensitivity of flow measurement uncertainty to head or time reading
uncertainty is proportional to the ratio of the device discharge equation
exponent to the reading. Furrow flow measurement uncertainty varies
with the device and flow rate, but generally exceeds ±5% and often
exceeds ±10%. Maintaining uncertainty below ±10% requires flume
measurements in the upper 50% of their range, orifice measurements
with head readings greater than 13mm, and volumetric measurement
elapsed times greater than 4 seconds.

Item Type: Article
NWISRL Publication Number: 0648
Subjects: Research methodology
Mass Import - autoclassified (may be erroneous)
Depositing User: Dan Stieneke
Date Deposited: 20 Nov 2010 21:53
Last Modified: 06 Jan 2017 21:16
Item ID: 496