1、 ANSI/ASAE S436.1 JUN1996 (R2016) Test Procedure for Determining the Uniformity of Water Distribution of Center Pivot and Lateral Move Irrigation Machines Equipped with Spray or Sprinkler Nozzles American Society of Agricultural and Biological Engineers ASABE is a professional and technical organiza
2、tion, of members worldwide, who are dedicated to advancement of engineering applicable to agricultural, food, and biological systems. ASABE Standards are consensus documents developed and adopted by the American Society of Agricultural and Biological Engineers to meet standardization needs within th
3、e scope of the Society; principally agricultural field equipment, farmstead equipment, structures, soil and water resource management, turf and landscape equipment, forest engineering, food and process engineering, electric power applications, plant and animal environment, and waste management. NOTE
4、: ASABE Standards, Engineering Practices, and Data are informational and advisory only. Their use by anyone engaged in industry or trade is entirely voluntary. The ASABE assumes no responsibility for results attributable to the application of ASABE Standards, Engineering Practices, and Data. Conform
5、ity does not ensure compliance with applicable ordinances, laws and regulations. Prospective users are responsible for protecting themselves against liability for infringement of patents. ASABE Standards, Engineering Practices, and Data initially approved prior to the society name change in July of
6、2005 are designated as “ASAE“, regardless of the revision approval date. Newly developed Standards, Engineering Practices and Data approved after July of 2005 are designated as “ASABE“. Standards designated as “ANSI“ are American National Standards as are all ISO adoptions published by ASABE. Adopti
7、on as an American National Standard requires verification by ANSI that the requirements for due process, consensus, and other criteria for approval have been met by ASABE. Consensus is established when, in the judgment of the ANSI Board of Standards Review, substantial agreement has been reached by
8、directly and materially affected interests. Substantial agreement means much more than a simple majority, but not necessarily unanimity. Consensus requires that all views and objections be considered, and that a concerted effort be made toward their resolution. CAUTION NOTICE: ASABE and ANSI standar
9、ds may be revised or withdrawn at any time. Additionally, procedures of ASABE require that action be taken periodically to reaffirm, revise, or withdraw each standard. Copyright American Society of Agricultural and Biological Engineers. All rights reserved. ASABE, 2950 Niles Road, St. Joseph, Ml 490
10、85-9659, USA, phone 269-429-0300, fax 269-429-3852, hqasabe.org ANSI/ASAE S436.1 JUN1996 (R2016) Copyright American Society of Agricultural and Biological Engineers 1 ANSI/ASAE S436.1 JUN1996 (R2016) Approved January 2011 as an American National Standard Test Procedure for Determining the Uniformity
11、 of Water Distribution of Center Pivot and Lateral Move Irrigation Machines Equipped with Spray or Sprinkler Nozzles Developed jointly by The Irrigation Association and the ASAE Sprinkler Irrigation Committee; approved by the ASAE Soil and Water Division Standards Committee; adopted by ASAE June 198
12、3; reconfirmed December 1988; approved as an American National Standard May 1989; revised editorially June 1989; reconfirmed December 1989, December 1990, December 1991; reaffirmed by ANSI September 1992; reaffirmed by ASAE December 1992, December 1993, December 1994, December 1995; revised June 199
13、6; revision approved by ANSI October 1997; revised editorially September 1998; reaffirmed by ASAE January 2001; reaffirmed by ANSI March 2001; reaffirmed by ASAE December 2001, February 2006, January 2007; reaffirmed by ANSI January 2007; reaffirmed by ASABE January 2012; reaffirmed by ANSI February
14、 2012; reaffirmed by ASABE and ANSI December 2016. Keywords: Irrigation, Sprinkler, Test 1 Purpose and scope 1.1 The purpose of this Standard is to define a method for characterizing the uniformity of water distribution of sprinkler packages installed on center pivots and lateral move irrigation mac
15、hines. This test produces data to be used in computing the coefficient of uniformity, which can assist in system design and/or selection, and can be used to quantify certain aspects of system performance in the field. The coefficient of uniformity is only one factor in evaluating total system perfor
16、mance. Application rates, runoff, wind, amount of water applied, pump performance, and overall system management can greatly affect the total performance of irrigation systems. 1.2 This Standard specifies a method for measuring water application depths in the field and calculating a coefficient of u
17、niformity from the data. The Standard covers evaluation of water distribution from center pivots and lateral move irrigation machines equipped with sprinklers or spray devices. The Standard does not apply to systems in which the water application device is less than 1.5 m above the soil surface, or
18、in which the water distribution from adjacent devices does not overlap. 2 Normative references The following standard contains provisions which, through reference in this text, constitute provisions of this Standard. At the time of publication, the edition indicated was valid. All Standards are subj
19、ect to revision, and parties to agreements based on this Standard are encouraged to investigate the possibility of applying the most recent edition of the Standard indicated below. Standards organizations maintain registers of currently valid Standards. ASAE S526.1 DEC96, Soil and Water Engineering
20、Terminology ANSI/ASAE S436.1 JUN1996 (R2016) Copyright American Society of Agricultural and Biological Engineers 2 3 Definitions 3.1 effective length of the lateral move system: The nominal distance parallel to the pipeline that is to be irrigated. Calculated as the distance between the terminal dev
21、ices (see clause 3.5) on ends of the pipeline, plus 75% of the wetted radius of each terminal device. If a portion of the area under the pipeline is used for the water supply system and not for crop production, that distance should not be included in the definition of the effective length. For this
22、case, the effective length is the distance between the terminal sprinkler or spray devices on each end of the lateral, plus 75% of the wetted radius of each terminal water applications device, minus the distance used for the water supply system. An alternative definition for effective length may be
23、used, and shall be clearly stated in the test results. 3.2 effective radius of the center pivot: The nominal radius of the circular field area that is to be irrigated. Calculated as the distance from the pivot point to the terminal sprinkler or spray device on the pipeline, plus 75% of the wetted ra
24、dius of the terminal water application device. If an alternative definition for effective radius is used, it shall be clearly stated in the test results. 3.3 endgun: A set of one or more sprinklers installed on the distal end of a center pivot or lateral move machine to increase the irrigated area.
25、The endgun operates a fraction of the time required to irrigate the entire field. Sprinklers at the distal end of the machine that operate continuously while the field is being irrigated are not considered endguns. 3.4 sprinkler package: A collection of water distribution devices fitted to the outle
26、ts of either a center pivot or a lateral move system. The devices may consist of sprinklers, spray devices, piping, pressure or flow control devices, and supporting plumbing designed for a specific machine and set of operating parameters. 3.5 terminal device: The sprinkler or spray device at the mov
27、ing end of a center pivot system or at one or both ends of a lateral move system. The terminal device operates continuously and is not an endgun. 3.6 test pressure: The pressure at the inlet where water enters the lateral pipeline. The test pressure shall be measured at the first available outlet do
28、wnstream of the inlet to the pipeline. 3.7 wetted radius: Distance measured from the sprinkler or spray device centerline to the farthest point at which deposition of water declines to approximately 1 mm/h. The wetted radius is based on tests conducted when there was no wind. For the purposes of thi
29、s test, the wetted radius can be estimated from manufacturers catalog data as half of the diameter of coverage, or by observation of the machine operating in the field. 4 Test conditions and equipment 4.1 Collectors 4.1.1 All collectors used in the test to measure the depth of water applied shall be
30、 identical and shaped such that water does not splash in or out. The lip of the collector shall be symmetrical and without depressions. The height of the collectors shall be at least 120 mm. The entrance diameter of the collector shall be one-half to one times its height, but not less than 60 mm. Th
31、e collector should be of a light color to reflect solar radiation and minimize evaporation. 4.1.2 The collectors shall be spaced uniformly along two or more straight lines perpendicular to the direction of travel of the machine (see figures 1 and 2). The collector spacing along each line shall not b
32、e more than 3 m for spray devices and 5 m for impact sprinklers. Collectors can be moved to avoid wheel tracks. If possible, the collector spacing should not be an even multiple or fraction of the sprinkler or spray device spacing. The location of the collectors shall be recorded. ANSI/ASAE S436.1 J
33、UN1996 (R2016) Copyright American Society of Agricultural and Biological Engineers 3 Figure 1 Collector layout for determining the water distribution of center pivot irrigation machines Figure 2 Collector layout for determining the water distribution of lateral move irrigation machines 4.1.3 The col
34、lectors shall be located so that obstructions, such as the crop canopy, do not interfere with the measurement of water application. When the obstruction is higher than the elevation of the collector, but below the nozzle height, an unobstructed space of at least twice the distance between the height
35、 of the obstruction and the top of the collector shall be maintained on both sides of the collector rows as shown in figure 3. For systems with nozzles that operate below the crop canopy height, an unobstructed distance of at least 1.25 times the wetted radius of the sprinkler shall be maintained on
36、 each side of the collector rows as shown in figure 3. Figure 3 Diagram of the required unobstructed area around the collectors ANSI/ASAE S436.1 JUN1996 (R2016) Copyright American Society of Agricultural and Biological Engineers 4 4.1.4 The entrance portion of the collectors shall be level. When win
37、d speeds during the test are expected to exceed 2 m/s, the collectors should be no more than 0.3 m above the ground or crop canopy. Nozzle and collector heights shall be recorded. The discharge elevation of the nozzle shall be at least 1 m above the elevation of the collector. 4.2 Wind velocity duri
38、ng the test period shall be measured with a rotating anemometer or equivalent device. 4.2.1 The wind direction, relative to the line of collectors, shall be determined with a vane indicating at least eight points of the compass. 4.2.2 The wind velocitymeasuring equipment shall be located at a minimu
39、m height of 2 m above the ground surface and within 200 m of the test site, in a location that is representative of the wind conditions at the test site. 4.2.3 The anemometer shall have a threshold velocity of 0.3 m/s or less and be capable of measuring the actual velocity to within 10%. 4.2.4 The w
40、ind velocity and prevailing direction at the time of the test shall be measured and recorded at intervals of not longer than 15 minutes. 4.2.5 Accuracy of this test procedure decreases when wind speeds exceed 1 m/s. If wind speed exceeds 5 m/s, this test may not be a valid measure of uniformity or t
41、he performance of the sprinkler package. Any results obtained when wind speeds exceed 5 m/s shall be prominently labeled with “wind speeds during this test exceeded the criteria of ASAE S436.” 4.3 It is recommended that the test be conducted during periods that minimize the effect of evaporation suc
42、h as at night or during early daylight hours. Dry bulb temperature and a humidity parameter (wet bulb temperature, relative humidity, or dew point temperature) shall be measured upwind of the machine and recorded near the beginning and at the end of the test. The time of measurement shall be recorde
43、d. 4.3.1 To minimize the effect of evaporation from collectors during the test, the volume of water in each collector shall be measured and recorded as soon as water application at the specific collector is complete. If the volume caught in each collector will be adjusted for evaporation loss, the t
44、ime that each collector contains water, i.e. from the time water reaches the collector until the collector volume is measured, shall be estimated. 4.3.2 If an adjustment is made on the collected data to account for evaporation from the collectors, a minimum of three control collectors containing the
45、 anticipated catch shall be placed at the test site and monitored to determine the rate of evaporation. Control collectors shall be located where the microclimate is essentially unaffected by the operation of the machine. The time that control collectors are measured shall be recorded. 4.3.3 Alterna
46、te procedures for minimizing evaporation are to use an evaporation suppressant or a specially designed collector. The methods used to suppress evaporation shall be recorded. 4.4 The test shall be conducted in an area that has elevation differences that are within the design specifications of the spr
47、inkler package. Elevation differentials should be measured with an instrument capable of measuring an elevation change of 0.2 m in a 50-m length. A sketch of the ground surface profile along each line of collectors should be included with the test results. 5 Test procedures 5.1 General 5.1.1 Before
48、a machine is tested, it shall be verified that the sprinkler package has been installed and adjusted according to the design specifications. If not installed or adjusted properly, the package shall be corrected before testing. ANSI/ASAE S436.1 JUN1996 (R2016) Copyright American Society of Agricultur
49、al and Biological Engineers 5 5.1.2 The desired test pressure shall be specified prior to the test. For many applications the specified test pressure should match the pressure used to design the sprinkler package on the machine. The test pressure shall be recorded and shall be maintained during the test to within 5% of the specified test pressure. The pressure-measuring device shall be capable of accurately measuring to within 2% of the specified test pressure. 5.1.3 The machine shall be operated at a speed that will deliver an average d
