ISO 4406:2017 download free.Hydraulic fluid power — Fluids — Method For coding Ihe level ol contamination by solid particles.
1 Scope
ISO 4406 specifies the code to he used in defining the quantity of solid particles in the fluid used
In a given hydraulic fluid power system.
2 Normative references
The following documents are referred to in the test in such a way that some or all of their content coiitItutes requirements o ISO 4406. For dated references, only the edition cited applies For undated rcfvrences. the latest edition of the referenced document (including any amendnwnts) applies.
ISO 4407, liydruu& fluid power — Fluid co,itnmimrtiun — Determination oj part kulate CnWtufliflalI.)lS liv the counting method using on optical mkroscope
ISo 11171, Hydraulic fluid power — Calibration of uutvmutic particle coo titers fur liquids
1St) 11500. Hyd rauhc fluid power — Determination of the particulate contamination level of a liquid sample
by automatic particle countinq usmg the light-extinction principle
3 Code delinition
3.1 General
The purpose oF this code is to simplify the reporting of particle count data by converting the numbers of particles into broad classes or codes, where an increase in one code is generally a douhling of the contamination level.
The original code. in accordance with the first edition of ISO 4406. stated the reporting at two sizes  5 pm and IS pm. The sizes In ISO 4406 account for the use of a different calibration standard for optical automatic particle counters (APCs). The reported sizes are  4 pm(c),  6 pm(c) and
14 pm(c). thy last two of these being equivalent to the 5 pm and IS im particle sizes obtained using the 1St) 4402:199111 method of calibrating APCs. Throughout this document the use of pm(c) means that particle size measurements are carried out using .in automatic particle counter that has been calibrated in accordance with ISO 11171.
Measurement of particles using an optical niluroscope as specified in ISO 4407 establishes the size of
a particle as being equal to its longest dimension, whereas an automatic particle counter derives the
size of an equivalent particle from its cross’sectional area, a value dilirrent in most cases from that
detvrnilrwd using a microscope. The particle sizes to be reported for measurement by microscope
≥ 5 pm and ≥ 15 pm are Linchanged froni those specified in the first edition of this document.
CAUTION — Particle counts are affected by a variety of factors. These factors include procurement of sample, particle counting accLaracy and the sample container (where used), and its cleanliness. Proper care should be take.i during sample procurement to ensure that the sample obtained Is representative olihe fluid circulation lit the system.
3.2 Bask of code
The rode br contamination levels using automatic particle counters comprises three scale numbers that permit the chflerentiation of the dimension arid ISO 4406 of the particles as lolluws:
— the lirst scale number represents the number of particles equal to or larger than 4 pm(c) per rnillihtre oifluid
— the second scale number represents the number ni particles equal to or larger than 6 pm(c) per nullilitre offluid;
— the third scale number represents the number ol particles equal to or larger than 14 prn(c) per millihtre nil luid.
The code br microscope counting comprises two scale numbers using 5 pm and IS pm.
3.3 Allocation of scale numbers
3.3.1 The scale numbers are allocated according to the number nlparftcles counted per millilitre of the Iluid sample (see ThhI.I).
3.3.2 A step ratio of generally two, as given betweeii the upper and lower limits for the number of particles per millilitre in Tihh. 1, has been adopted to keep the number of scale numbers within a reasonable limit and to ensure that each step is meaningfuL
3.4 Determination of code using autonialic particle counter analysis
3.4.1 Counting shall be undertaken in accordance with ISO 11500 or another recognixed method.
using an APC calihrawd to ISO II l7I
3.4.2 A scale number shall be allocated to the number of particles equal to or larger than 4 pm(c).
3.4.3 A second scale number shall be allocated to the number of particles equal to or larger than
6 lIm(c).
3.4.4 A (herd scale number shall he allaxatetl to Cite number of particles equal to or larger than
14 lam(c).
3.45 The three numbers shall he written alne alter the other and separated by oblique stmkes (slashes).
lXAMPIL A Lode ol 22/111/13 signIfies that there are more tItan 20 (100 and up to and Imluding 40 000 ltartIcLes equal to or larger (hati 4 pnifr). more than I 11)0 and up to md Including 2 504) particles equal to or bi’grr than 6 pm(s) and mure than 40 and up to ,ami umsiudemig HO particles equal to or target than 14 im(c) in I ml nt a given Fluid %.unplc
3.4.6 When applicable, include either — (hut nuniernus to count) or (no requsn?ment to count) notation when reporting the scale number.
IXAMILE I /19J14 means that this sample has too ni.iny partklcs equal to or larger than 4 tirilK) to (1)0111.
lXAMPl,E 2 —/19/14 means that (hers’ was no ,enlulrvmncnt tam count partisis’s equal to air larger thati 4 (am(s),
3.4.7 When the raw daa en one ni the size ranges results ifl .1 particle count at fewer than 20 particles, the scale number br that size range shall he labelled witit the symbol .
IXAMPI.E A sgxlr ul 14/I 2/7 signitis’s tli.it there .ua more than HO .tnnl up to and Insluding IOu particles equal In or larger than 4 pmfr) per mniIllll(rv iid inure tI,.iii 20 arid up to and Inslusling 44) particles equal In or larger than 6 pntfr) per millihirs, Titi’ third plan ol 11w onle. 7. Indicates that thereare flints’ thJII (1.64 and up to and including 1.1 particles equal to or larger than t4 (atn(c) pen ntdlltlirr hut less than 20 particles were sminted whu.h lowers statistical confidence. Hecause ot (Ins lower crintldeiice. the 14 im(L) part ot the cods’ can he higher titan 7, lndk-ateng.l particle (oUlu 01 more Ih.iii I .1 partlales per millilitrs’.
3.5 Determination oF code using miroscopc sizing
3.5.1 Counting shall be undertaken in accordance with 1St) 44(17.
33.2 A scale number shall be allocated to the nuniher ol particles equil tour larger than 5 pm.
3.5.3 A second scale number shall 1w allocated to tiw number oF particles equal to or Larger than 15 ini,
3.5.4 In order to relate to counts obtained with an automatic particle counter, the code shall be stated in three-part form with the first part given as
XAMPLI —/18/13.
4 Identification statement (reFerence to this document)
Use the Following statenient in lest reports, catalogues aiid sales literature when clectmg to comply with this docurncnL
SaIid contaminant code conlorms to ISO 4406, Uyffruulic fluid power — Fluids — Method [or coding the eiei n/cant atninat ion by solid particles.