ISO 5884:2018

INTERNATIONAL ISO
STANDARD 5884
Second edition
2018-08
Aerospace series — Fluid systems
and components — Methods for
system sampling and measuring
the solid particle contamination in
hydraulic fluids
Série aérospatiale — Systèmes de fluides et éléments constitutifs
— Méthodes de prélèvement et de mesure de la contamination
particulaire solide dans un fluide hydraulique
Reference number
©
ISO 2018
© ISO 2018
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Published in Switzerland
ii © ISO 2018 – All rights reserved

Contents Page
Foreword .iv
0 Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Sampling apparatus . 1
4.1 General . 1
4.2 Sampling apparatus characteristics . 2
4.2.1 Manual sampling apparatus . 2
4.2.2 Automated sampling apparatus . 2
4.3 Sample apparatus preparation . . 3
4.3.1 General. 3
4.3.2 Solvents . 4
4.3.3 Cleaning procedure for sampling apparatus . 5
4.3.4 Cleaning procedure for sample bottles . 5
4.3.5 Checking and controlling cleaning methods . 6
5 Sampling . 6
5.1 General . 6
5.2 Recommendations for sampling point location . 6
5.3 Sampling frequency . 7
5.4 Sampling methods . 7
5.4.1 General. 7
5.4.2 Sampling method A — Field monitor/PCM system . 7
5.4.3 Sampling method B — Sampling valve (using sample bottles) . 8
5.4.4 Sampling method C — Reservoir sampling with vacuum pump and tubing . 9
5.4.5 Sampling method D — Reservoir sampling with direct bottle dipping . 9
5.5 Sample marking .10
6 Sample analysis methods .10
7 Test reporting .10
7.1 General .10
7.2 Test report form .10
7.3 Minimum data to be included in the test report form .11
7.4 Example test report .11
Annex A (informative) Example test report template .12
Bibliography .13
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
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ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
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on the ISO list of patent declarations received (see www .iso .org/patents).
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URL: www .iso .org/iso/foreword .html.
This document was prepared by ISO/TC 20, Aircraft and space vehicles, Subcommittee SC 10, Aerospace
fluid systems and components.
This second edition cancels and replaces the first edition (ISO 5884:1987), which has been technically
revised. The main changes compared to the previous edition are as follows:
— update of the document to be in line with current ISO rules;
— improved layout and clarity in definition;
— removal of sample analysis detail, with reference to relevant ISO method instead;
— improved sampling point recommendations;
— improved clarity of sampling methods and recommendations for preference.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www .iso .org/members .html.
iv © ISO 2018 – All rights reserved

0 Introduction
0.1 General
The design of modern hydraulic equipment for aerospace purposes, its use and performance are widely
determined by the type and condition of the applicable hydraulic fluids.
The quality and serviceability of hydraulic fluids are dependent on various factors (e.g. thermal stability,
viscosity), but in particular on the level of solid particle contamination. Regular fluid contamination
testing is required to determine if the fluid is maintained within specified limits that are set by the
aircraft manufacturer or hydraulic system operator.
In order to obtain consistent and comparable test results, the test methods detailed in this document
should be used.
As a result of the rapid development and improvement of hydraulic systems and their components,
which meet critical requirements, the problem of solid particle contamination of hydraulic fluids has
steadily increased. The need for maintaining a specified standard of fluid cleanliness in hydraulic
systems requires continuous control of the number and size of the solid particle contaminants.
0.2 Solid particle contamination
Solid particle contaminants can be the cause of abrasion and wearing, thereby shortening the life of the
components in a hydraulic system.
In a hydraulic system:
a) components are subject to erosion (primarily in components with higher fluid velocities);
b) all moving parts are subject to wear by abrasion; and
c) control valves are subject to silting (settlement of fine particles on the control bore).
0.3 Causes of solid particle contamination
Solid particle contamination of hydraulic fluids can be system-generated, introduced from the outside,
in-built or maintenance-generated, for example:
a) dust particles in the air;
b) metal particles, produced during the manufacture of parts;
c) sand residues on castings;
d) abrasion of seals;
e) oxide layers on welding seams and on heat-formed or heat-treated steel parts;
f) chemical and physical changes in the condition of hydraulic fluids;
g) maintenance of hydraulic systems (e.g. fibres, secondary contamination, etc.);
h) wear of components from abrasion, adhesion and fatigue; and
i) ingress of particles via piston gland seals.
0.4 Layout of this document
This document is sub-divided into the following clauses:
— Sampling apparatus (Clause 4):
— Characteristics;
— Preparation;
— Sampling (Clause 5):
— Recommendations for sampling point location;
— Recommendation of sampling frequency;
— Sampling methods;
— Recommendation of sample marking;
— Sample analysis methods (Clause 6);
— Test report recommendations (Clause 7).
vi © ISO 2018 – All rights reserved

INTERNATIONAL STANDARD ISO 5884:2018(E)
Aerospace series — Fluid systems and components —
Methods for system sampling and measuring the solid
particle contamination in hydraulic fluids
1 Scope
This document specifies best practice for sampling hydraulic fluid from aircraft hydraulic systems and
other hydraulic systems associated with aerospace purposes.
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.
ISO 3696, Water for analytical laboratory use — Specification and test methods
ISO 3722, Hydraulic fluid power — Fluid sample containers — Qualifying and controlling cleaning methods
ISO 4021, Hydraulic fluid power — Particulate contamination analysis — Extraction of fluid samples from
lines of an operating system
ISO 4405, Hydraulic fluid power — Fluid contamination — Determination of particulate contamination by
the gravimetric method
ISO 4406, Hydraulic fluid power — Fluids — Method for coding the level of contamination by solid particles
ISO 4407, Hydraulic fluid power — Fluid contamination — Determination of particulate contamination by
the counting method using an optical microscope
ISO 11171, Hydraulic fluid power — Calibration of automatic particle counters for l
...