Butlig, Felipe Tancio creator Apichart Anukularmphai Chairperson Prida Thimakorn Co-Chairperson Olesen, Svend Elsnab Examination Committee Government of Australia Scholarship Donor text series technical report th Bangkok Asian Institute of Technology 1981 continuing eng 69 p. Three sizes of the vane-in-a-pipe flow measuring device (VIP) were tested at the Hydraulics laboratory of the Asian Institute of Technology. The sizes of VIP tested were 25.4 cm, 30.5 cm, and 38.1 cm, each having a length of 100 cm. These are equivalent to the standard sizes of reinforced concrete pipes (culverts) available in the market. Results of the study showed that the approach and exit flow conditions did not significantly affect the discharge through the device. Likewise, the variations of submergence ratios, did not significantly affect the discharge. Furthermore, discharges calculated using the theoretical equations of the three sizes of VIP did not significantly differ from the discharges calculated using the set of statistically derived discharge equations. All these parameters were tested at the 95% confidence interval as recommended by the International Standards Organization (ISO). Another significant result of the study showed the independence of the moment to variations in velocity for a given discharge. The VIP device is suitable in measuring flow with low velocity and flat gradient channels. It is not suggested as a blanket replacement for other flow measuring devices. Instead, it could serve as a valuable addition to the researchers list of tools complementing the traditional weirs and flumes. A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering, School of Environment, Resources and Development Thesis (M.Eng.) - Asian Institute of Technology, 1981 Flow meters Calibration Asian Institute of Technology. http://203.159.5.9/ait-thesis/detail.php?q=B21507 http://203.159.5.9/ait-thesis/detail.php?q=B21507 230998 20260817172058.0