TY - JOUR T1 - Evaluation of hydraulic characteristics of several types of drip irrigation tapes TT - ارزیابی مشخصه های هیدرولیکی چند نوع از نوارهای آبیاری قطره ای JF - JSTNAR JO - JSTNAR VL - 21 IS - 1 UR - http://jstnar.iut.ac.ir/article-1-2821-en.html Y1 - 2017 SP - 159 EP - 169 KW - Emission uniformity KW - flow rate coefficient of variation KW - manufacturing coefficient of variation KW - quality index. N2 - The main purpose of this study is investigation of hydraulic properties in drip irrigation tape. In this study, 10 types of drip irrigation tape were tested, and the effect of 4 temperatures of water, 13, 23, 33 and 43 °C, was investigated according to the standard ISO 9261 and ISO IRISI. Initially all experiments were performed in standard temperature (23°C) in order to obtain qualitative evaluation indexes of tapes. The results obtained were as follows: According to the Cv, 8 models of tapes were ranked as good and 2 models as medium. According to the difference between the actual and nominal flow rates, 3 models were ranked as good, 3 models as medium, 3 models were acceptable and 2 models were unacceptable. According to the EU, 9 models were ranked as excellent and T3 was ranked as good. According to the UC, UC of all models was more than 70% and their flow rate variation follows normal distribution. According to qvar, flow rate changes in 3 models were acceptable, 2 models were ranked as good and 5 models were unacceptable. M3 10.18869/acadpub.jstnar.21.1.159 ER -