ISO 15886-3:2012

Agricultural irrigation equipment - Sprinklers - Part 3: Characterization of distribution and test methods

ISO 15886-3:2012 specifies the conditions and methods used for testing and characterizing the water distribution patterns of irrigation sprinklers. The term sprinkler is used in a broad generic sense and is meant to cover a wide variety of products as classified by ISO 15886-1. The specific performance measurements addressed include distribution uniformity, wetted radius, and water jet trajectory height. This standard applies to all irrigation sprinkler classifications for which these three performance measurements are required to verify the design objectives as defined by the manufacturer. ISO 15886-3:2012 deals both with indoor and outdoor tests and with radial and full grid tests. It is organized so as to deal with conditions common to all tests first and then with conditions unique to indoor testing only and finally with conditions unique to outdoor testing only. For any given sprinkler, a wide range of nozzle configurations, operating conditions, and adjustments generate at least a theoretical need for a correspondingly large number of tests. Testing agencies and manufacturers may use interpolation techniques to reduce the number of actual test runs provided accuracy standards are still being met. ISO 15886-3:2012 does not address the specific performance testing required for sprinklers intended for use in frost protection. It also does not address the topic of drop spectrum measurement and characterization and the related questions of soil compaction, spray drift, evaporative losses, etc., all of which can be considerations in the design of sprinkler irrigation systems. To apply ISO 15886-3:2012 for evaluating irrigation coverage, all sprinklers must be identical and arranged in a fixed repeating geometric pattern. ISO 15886-3:2012 does not apply to moving systems. ISO 15886-3:2012 applies to part-circle sprinklers provided that the testing agency can satisfy questions of potential anomalies in performance parameters. One annex addresses the procedures for the characterization of sprinkler pattern uniformity; another addresses testing part-circle sprinklers.

Matériel agricole d'irrigation — Asperseurs — Partie 3: Caractérisation de la distribution et méthodes d'essai

General Information

• Status: Withdrawn
• Publication Date: 02-Sep-2012
• Withdrawal Date: 02-Sep-2012
• ICS: 65.060.35 - Irrigation and drainage equipment
• Technical Committee: ISO/TC 23/SC 18 - Irrigation and drainage equipment and systems
• Drafting Committee: ISO/TC 23/SC 18/WG 3 - Irrigation sprinklers
• Current Stage: 9599 - Withdrawal of International Standard
• Start Date: 12-Mar-2021
• Completion Date: 13-Dec-2025

Relations

• Amended By: ISO 15886-3:2012/Amd 1:2016 - Agricultural irrigation equipment - Sprinklers - Part 3: Characterization of distribution and test methods - Amendment 1
• Effective Date: 25-Dec-2021
• Revised: ISO 15886-3:2021 - Agricultural irrigation equipment - Sprinklers - Part 3: Characterization of distribution and test methods
• Effective Date: 23-Apr-2020
• Revises: ISO 15886-3:2004 - Agricultural irrigation equipment - Sprinklers - Part 3: Characterization of distribution and test methods
• Effective Date: 04-Feb-2009

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 15886-3
Second edition
2012-09-15
Agricultural irrigation equipment —
Sprinklers —
Part 3:
Characterization of distribution and
test methods
Matériel agricole d’irrigation — Asperseurs —
Partie 3: Caractérisation de la distribution et méthodes d’essai
Reference number
©
ISO 2012
© ISO 2012
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any
means, electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the
address below or ISO’s member body in the country of the requester.
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Published in Switzerland
ii © ISO 2012 – All rights reserved

Contents Page
Foreword .iv
1 Scope . 1
2 Terms and definitions . 1
3 Collectors . 4
3.1 Collector design . 4
3.2 Collector orientation . 4
4 Installation of sprinklers under test. 5
5 Measurements . 6
5.1 Accuracy of measurements . 6
5.2 Pressure measurement . 6
5.3 Atmospheric conditions measurements . 7
5.4 Corrections for evaporative losses within collectors . 7
6 Collector arrangement, spacing and number . 8
6.1 Full grid collector array method . 8
6.2 Radial collector array method . 8
7 Additional tests . 9
7.1 Time of rotation . 9
7.2 Trajectory height . 9
8 Test operation . 9
8.1 Rotation of sprinkler riser . 9
8.2 Test duration . 9
8.3 Other test details . 9
9 Test location specifications .10
9.1 Indoor testing building specifications .10
9.2 Outdoor site specification.10
10 Characterization of distribution .11
10.1 Introduction .11
10.2 Application pattern coverage and uniformity .11
10.3 Generating performance measurements from radial arrays .11
10.4 Validation of test results .12
Annex A (informative) Procedures for the characterization of sprinkler pattern uniformity .13
Annex B (informative) Testing of part-circle sprinklers .17
Bibliography .18
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International
Standards adopted by the technical committees are circulated to the member bodies for voting.
Publication as an International Standard requires approval by at least 75 % of the member bodies
casting a vote.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights.
ISO 15886-3 was prepared by Technical Committee ISO/TC 23, Tractors and machinery for agriculture
and forestry, Subcommittee SC 18, Irrigation and drainage equipment and systems.
This second edition cancels and replaces the first edition (ISO 15886-3:2004), which has been
technically revised.
ISO 15886 consists of the following parts, under the general title Agricultural irrigation equipment —
Sprinklers:
— Part 1: Definition of terms and classification
— Part 3: Characterization of distribution and test methods
iv © ISO 2012 – All rights reserved

INTERNATIONAL STANDARD ISO 15886-3:2012(E)
Agricultural irrigation equipment — Sprinklers —
Part 3:
Characterization of distribution and test methods
1 Scope
This part of ISO 15886 specifies the conditions and methods used for testing and characterizing the
water distribution patterns of irrigation sprinklers. The term sprinkler is used in this standard in a
broad generic sense and is meant to cover a wide variety of products as classified by ISO 15886-1. The
specific performance measurements addressed include distribution uniformity, wetted radius, and
water jet trajectory height. This standard applies to all irrigation sprinkler classifications for which
these three performance measurements are required to verify the design objectives as defined by the
manufacturer.
This part of ISO 15886 deals both with indoor and outdoor tests and with radial and full grid tests. It
is organized so as to deal with conditions common to all tests first and then with conditions unique to
indoor testing only and finally with conditions unique to outdoor testing only.
For any given sprinkler, a wide range of nozzle configurations, operating conditions, and adjustments
generate at least a theoretical need for a correspondingly large number of tests. Testing agencies and
manufacturers may use interpolation techniques to reduce the number of actual test runs provided
accuracy standards are still being met.
This part of ISO 15886 does not address the specific performance testing required for sprinklers
intended for use in frost protection.
This part of ISO 15886 does not address the topic of drop spectrum measurement and characterization
and the related questions of soil compaction, spray drift, evaporative losses, etc., all of which can be
considerations in the design of sprinkler irrigation systems.
To apply this part of ISO 15886 for evaluating irrigation coverage, all sprinklers must be identical and
arranged in a fixed repeating geometric pattern. This part of the standard does not apply to moving systems.
This part of ISO 15886 applies to part-circle sprinklers provided that the testing agency can satisfy
questions of potential anomalies in performance parameters.
Annex A addresses the procedures for the characterization of sprinkler pattern uniformity. Annex B
addresses testing part-circle sprinklers.
2 Terms and definitions
For the purpose of this part of ISO 15886, the following terms and definitions apply.
2.1
ambient temperature
temperature of the air surrounding a sprinkler test site
2.2
area of coverage
wetted area from a sprinkler operated as specified in the manufacturer’s literature where water is
deposited at rates equal to or greater than the effective application rate
2.3
Christiansen’s uniformity coefficient
UCC
coefficient using deviations from the mean to characterize the uniformity of field-measured or simulated
water application from a grid of sprinklers
2.4
clean water
water processed, if necessary, so as to contain suspended particles no larger than 200-mesh equivalent
(74 µm) and to contain no dissolved chemicals known to have short-term effects on sprinkler materials
2.5
collector
receptacle into which water is deposited during a water distribution test
2.6
critical dry area
experienced-based definition of the dry area size that defines uniformity of coverage objectives
2.7
densogram
areal map utilizing the density of dots representing the water application depth at locations in the areas
of coverage of a sprinkler or a grid of sprinklers
2.8
distribution uniformity
DU
coefficient using the lowest 25 % of water application depths to characterize the uniformity of field-
measured or simulated water application from a grid of sprinklers
2.9
minimum effective water application rate
application rate equal to or exceeding 0,26 mm/h for sprinklers with flow rates exceeding 75 l/h and
0,13 mm/h for sprinklers with flow rates equal to or less than 75 l/h
2.10
effective radius of throw
radius at which 95 % of the reconstituted volume of water discharged by a sprinkler, interpolated
between points of measurement, is applied
2.11
flow rate
volume of water flowing through an irrigation component per unit of time
2.12
full grid collector array
collectors located at the intersections of a two-dimensional geometric grid pattern sufficient in number
to give a desired statistical basis for determining water distribution uniformity
2.13
inlet connection size
nominal pipe size designation for commercial purposes or to manufacturer’s declaration defined by
reference to a recognized standard
2.14
irrigation lateral
branch supply line in an irrigation system on which sprinklers are mounted directly or by means of
fittings, risers, or tubes
2 © ISO 2012 – All rights reserved

2.15
maximum working pressure
Pmax
highest pressure at the inlet to a sprinkler recommended by the manufacturer to ensure proper operation
2.16
minimum working pressure
Pmin
lowest pressure at the inlet to a sprinkler recommended by the manufacturer to ensure proper operation
2.17
nozzle
aperture of a sprinkler through which the water is discharged
NOTE A sprinkler may contain one or several cylindrical nozzles, or nozzles of other shapes. This term may refer
to either a single nozzle, or to a combination of nozzles in a multi-nozzled sprinkler.
2.18
part-circle sprinkler
sprinkler with an adjustable feature that enables it to irrigate a sector of a circular area either with or
without an attachment which enables it to be adjusted to irrigate another sector or the entire circular area
2.19
pop-up sprinkler
sprinkler designed for installation so that the sprinkler nozzle automatically rises from below ground
when the system is pressurized and automatically lowers to its original position when the system is
depressurized
2.20
pressure tap
precisely fabricated connection for accurately communicating internal conduit pressure to an external
pressure-measuring device
2.21
radial collector array
collectors located only on the radial axis projected from the centerline of a sprinkler sufficient in number
to characterize the water distribution curve
2.22
radius of throw
wetted radius
distance measured from the centerline of a continuously-operating sprinkler to the most remote point
at which the sprinkler deposits water at the minimum effective water application rate measured at any
arc of coverage except near the arc extremes for part-circle sprinklers
2.23
rotating sprinkler
water distribution device which, as a result of rotating motion around its vertical axis, distributes water
over a circular area, part of a circular area, or a non-circular area
2.24
scheduling coefficient
SC
coefficient used to characterize the water uniformity of water application of sprinklers employing an
analysis of full-grid data based on a definition of critical dry area
2.25
sprinkler spacings
conventional designation including the distance between the sprinklers along an irrigation lateral and
the distance between consecutive irrigation laterals
2.26
statistical uniformity coefficient
UCS
coefficient using standard deviation as a measure of dispersion in statistical theory to characterize the
uniformity of field-measured water application from a full grid of sprinklers
2.27
test pressure
pressure at the inlet of a sprinkler declared by the manufacturer as the pressure to be used for test purposes
2.28
maximum trajectory height
maximum height above a sprinkler of the water stream discharged from the sprinkler nozzle operating
at test pressure
2.29
water application rate
mean depth of water applied per unit time
2.30
water distribution curve
graphical plot of water application depth as a function of distance from a sprinkler along a specified radius
2.31
wind speed
speed of the wind at a test site averaged over the time required for a sprinkler distribution uniformity test
2.32
working pressure
water pressure range recommended by the manufacturer to ensure proper operation of a sprinkler
3 Collectors
3.1 Collector design
All collectors used for any one test shall be identical. They shall be designed to minimize water splashes
in or out and distortions of the catchment volume as may be caused by wind currents.
The height of a collector shall be at least twice the maximum depth of the water collected during the test,
but not less than 150 mm.
The collectors shall have a circular opening with sharp edges free from deformities. The diameter shall
be between 1/2 to 1 times the height, but not less than 85 mm.
Alternative collector designs may be used, provided that their measuring accuracy is not less than of
those described above.
The catchment from a collector shall be quantified from a direct reading of mass, depth, or a volumetric
determination provided that the required accuracy standard is met.
3.2 Collector orientation
The openings of all collectors shall be in a common horizontal plane with a slope not exceeding 2 % in
any direction. The difference in height between any two adjacent collectors shall not exceed 20 mm.
For indoor testing, collector height is not critical. For outdoor testing, the collector height shall be
sufficient to ensure that vegetation does not interfere with jet access to the collectors.
4 © ISO 2012 – All rights reserved

4 Installation of sprinklers under test
The sprinkler selected for testing shall be representative of general production capabilities particularly
as relates to the speed of rotation. New sprinklers shall be operated before the test for a period sufficient
to demonstrate that the time per revolution has stabilized to ± 5 %.
Mount the sprinkler on a riser with the same nominal size designation as the sprinkler inlet connection.
Ensure that the riser is fixed rigidly vertically, and that it does not vibrate sufficiently to cause a visual
effect on the sprinkler operation, bend or deviate from the vertical during the test. The maximum
allowable deviation from the vertical during the test shall not exceed 2°.
A steel pipe riser is recommended to provide the required mechanical strength and facilitate the
installation of a standard pressure tap.
The sprinkler nozzle height above the collectors should simulate the conditions under which the
sprinkler is normally used. For example, with the turf sprinklers the top of the sprinkler body should
coincide with the top of the collectors.
For agricultural sprinklers used under a variety of field conditions the following height requirement
applies: The height of the principal sprinkler nozzle above the openings of the collectors shall be selected
from Table 1. Manufacturers can request additional heights but those in Table 1 must be included.
Table 1 — Sprinkler height
Sprinkler flow rate Sprinkler nozzle height above the collector
l/h m
Pop-up 0
(in a non-pressurized state)
0 to 300 0,3
301 to 1 500 0,5
1 501 to 2 500 1,0
> 2 500 1,5
If the manufacturer specifies any special test-related conditions, for example, testing at a minimum riser
height or with straightening vanes, they shall be used if such items are provided as standard equipment
with the sprinkler.
For a sprinkler that is not riser-mounted as described in above, the mounting shall be as specified by the
manufacturer.
For single leg distribution patterns, a shelter may be used around the sprinkler to contain jet action
provided the following conditions are met:
— The shelter is large enough and so constructed as to trap the water jets and not let them interfere
with the sprinkler’s operation or contribute to the collector catchment.
— The shelter is designed to allow air circulation to develop around the jets.
— The shelter provides a minimum sector for unrestricted jet operation of 45° centred on the collector
radius. If the testing agency uses an angle less than 45°, it must demonstrate that the integrity of
the results is not compromised. Special attention shall be put to sector size, to avoid interception of
projections (spoon spit) generated by the impact arm.
— The shelter is designed so that no jet deflection or splash is directed into the collectors.
5 Measurements
5.1 Accuracy of measurements
Application depths within collectors shall be measured with an accuracy of ± 3,0 %.
Pressure shall be measured with an accuracy of ± 1,0 %.
Flow rate through the sprinkler shall be measured with an accuracy of ± 2,0 %.
Temperature shall be measured with an accuracy of ± 0,5 °C.
Time shall be measured with stop watches accurate to ± 0,1 s.
The accuracy required for all measurements not specifically addressed in this part of ISO 15886 is ± 3,0 %.
5.2 Pressure measurement
The test pressure shall be measured at the height of the main nozzle. The pressure tap construction
details are shown in Figure 1. There shall be no flow obstructions between the pressure tap and the
sprinkler base. The bore of the pipe containing the pressure tap shall be clean and smooth.
6 © ISO 2012 – All rights reserved

a) Thick wall
b) Thin wall
Key
1 pressure gauge
2 pressure tap
a
Internal diameter of the pipe.
Figure 1 — Pressure tap location and construction details
Figure 1 a), l ≥ 2,5d where d = 3 to 6 mm or 1/10 pipe diameter, whichever is smaller
Figure 1 b), l ≥ 2d; r ≤ d/10
5.3 Atmospheric conditions measurements
Relative humidity and ambient temperature shall be measured at the start, midpoint, and end of the
test. For indoor testing, changes in temperature and humidity during the test shall not exceed ± 5,0 % of
the pre-test ambient conditions.
Air conditioning systems may be required to ensure that the testing facilities meet this requirement.
5.4 Corrections for evaporative losses within collectors
Under some conditions, evaporative losses within collectors are known to result in measurement errors
that exceed the required accuracy of ± 3,0 %. Under these conditions, a correction to the collector
readings must be made using the following procedure:
Place a volume of water approximately equal to the average volume to be collected during the test in
each of three collectors. Locate the collectors near the test area but outside the area of water application.
Measure the volume of water before and after the test and apply the difference to the volume of water
in each collector.
6 Collector arrangement, spacing and number
6.1 Full grid collector array method
6.1.1 Method
This method refers to the use of a square grid of collectors with a s
...