ISO 25358:2018 作物保護装置—アトマイザーからの液滴サイズスペクトル—測定と分類 | ページ 2

Foreword

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This document was prepared by Technical Committee ISO/TC 23, Tractors and machinery for agriculture and forestry, Subcommittee SC 6, Equipment for crop protection.

Introduction

The measurement and classification of droplet size spectra for applications of pesticides and other chemicals facilitate the description of sprays and therefore enhance efficacy and spray drift management.

Most atomizers produce a spectrum of droplet sizes, giving different droplet size spectra in different operating conditions.

Measurement systems and laboratories can produce different absolute values for a given droplet spectrum. Differences are usually due primarily to sampling effects, dynamic size range capabilities, data processing and reporting. Some of these differences can be minimized through the use of appropriate sampling techniques. However, discrete differences in absolute values of droplet size spectra can still remain between measurement systems, especially where spatial size distribution (size distribution of particles in a given volume of space where there is no significant variation in the distribution during the sampling interval) and flux size distribution (size distribution of particles passing through a sampling zone during a given interval of time where individual particles are counted and sized)lead to sampling differences.

An approach that has been successfully used for describing spray droplet size spectra using standardized terminology involves the use of reference sprays to define reference categories for increased uniformity in the relative measures and classification of spray droplet spectra among different measurement systems and laboratories^[1][2]. This is the approach taken by this document.

Each measurement facility should determine its own “in-house” reference categories using this document (with one set for each measurement system and sampling method), and then classify sprays being measured using the same measurement and sampling procedures as those for the respective reference sprays. For example, reference curves from one source (laboratory, measuring instrument and sampling technique) cannot be used to classify sprays from a different measurement source.

Using the classification of droplet size spectra, it is also possible to provide appropriate information to the user.

1 Scope

This document specifies procedures for classifying droplet size spectra from atomizers used in spraying for crop protection. It provides a reference system for defining classes of droplet size spectra.

Depending on their function principle and individual setup, measuring systems for droplet sizing can give different results. This document provides a means of comparing measured droplet size spectra to reference spectra and enables relative comparisons of droplet size spectra obtained from different measuring systems.

2 Normative references

The following documents are referred to in the text in such a way that some or all of their content constitutes requirements of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.

3 Terms and definitions

For the purposes of this document, the terms and definitions given in ISO 5681 and the following apply.

ISO and IEC maintain terminological databases for use in standardization at the following addresses:

Bibliography