IS 9117-1979 Recommendations for liquid flow measurements in open channels through weirs and flumes - End depth method (approximation method) for estimating flows in non-rectangular channels with free overflow
1.1 This Indian Standard specifies a method for the estimation of subcriti-cal flow of clear water in smooth, essentially horizontal, straight open-channels with a vertical drop and discharging freely. Mild sustaining slopes not greater than 1 in 2 000 are admissible. This standard covers channels with the following types of cross section, the nappe being unconfined:
a) Trapezoidal,
b) Triangular,
c) Parabolic, and
d) Circular.
Using the measured depth at the end, the flow may be estimated.
The advantages and disadvantages of this device and other types of weirs and flumes as well as the relative accuracies of each of these de-vices are given in the draft Indian Standard Guide for the selection of weirs and flumes for the measurement of discharge of water in open channels (under preparation).
Note — Until the standard under preparation is published, the matter shall be subject to agreement between the concerned parties.
IS 9117-1979 history
1979IS 9117-1979 Recommendations for liquid flow measurements in open channels through weirs and flumes - End depth method (approximation method) for estimating flows in non-rectangular channels with free overflow