Tiêu chuẩn iso 08502 4 2017

© ISO 2017 Preparation of steel substrates before application of paints and related products — Tests for the assessment of surface cleanliness — Part 4 Guidance on the estimation of the probability of[.]

Preparation ofsteel substrates before

Part 4:

Pré aration des subjectiles d’acier a a t a plication de peinture s

et de produits assimilés — Essais p ur a précier la pro r té d’u e

surfc —

Partie 4 : Principes directeurs p ur l’e stimation de la pro a ilité de

co densation a a t a plication de peintur

S con edition

2 17-0

Refer ence n mb r

ISO 8 0 -4:2 17(E)

COPYRIGHT PROTECTED DOCUMENT

© ISO 2017, P blshed in Sw itz rlan

A ll rig hts r eserved Unles otherw ise spe ified, nopar of this p blc tion ma y be r epr od c d or utilz d otherw ise in an form

or b an me ns, ele tr onic or me hanic l, inclu in p oto opying , or postin on the internet or an intranet , w ithout prior

written permis ion Permis ion c n be req esed from either ISO at the ad r es below or ISO’s member bod y in the c u try of

F reword i v

Introduction vi

1 Sc ope 1

2 Nor mati ve r eferenc es 1

3 Probabiity of c ondensatio 1

4 Instruments 2

5 Proc ed re .3

6 Test rep r t 3

A nne x A (informative)Table for determination of dew-p int 5

Biblog raphy 26

ISO (he Int ernational Org nization for Stan ardization) is a worldwidefede ation of national s an ards

b dies (ISO membe b dies) The work of pr p ring Int ernational Stan ards is normaly car ied out

through ISO t ech ical committ ees Each membe b dy int er st ed in a subje t for w hich a t ech ical

committ ee has be n es a lshed has the right t o be r pr sent ed on that committ ee Int ernational

org nizations, g ove nmental an non-g ove nmental, in laison with ISO, also take part in the work

ISO cola orat es closely with the Int ernational Ele trot ech ical C mmis ion (IEC) on al matt ers of

ele trot ech ical s an ardization

The proc d r s used t o develo this document an those int en ed for it furthe maint enanc ar

desc ibed in the ISO/IEC Dir ctives, Part 1 In p rticular the dife ent a pro al c it eria ne ded for the

dife ent ty es of ISO document should be not ed This document was draft ed in ac ordanc with the

edit orial rules of the ISO/IEC Dir ctives, Part 2 ( e www iso org dir ctives)

A tt ention is drawn t o the p s ibi ity that some of the element of this document ma be the subje t of

p t ent right ISO shal not be held r sponsible for identifying any or al such p t ent right Detais of

any p t ent right identified d ring the develo ment of the document wi be in the Introd ction an / r

on the ISO ls of p t ent de larations r c ived ( e www iso org p t ent )

Any trade name used in this document is information given for the convenienc of use s an does not

cons itut e an en orsement

For an ex lanation on the meaning of ISO spe ific terms an ex r s ions r lat ed to conformity as es ment,

as wel as information a out ISO’s adhe enc to the Wor ld Trade Org nization (WTO) principles in the

Te h ical Bar ie s to Trade (TBT) se the folowing URL: www iso org iso/ for word html

This document was pr p r d b Te h ical Committ ee ISO/TC 3 , Paints a d v rni shes , Subcommitt ee

SC 1 , Prep ration o s te l s ubs trates befr a plc atio o p ints a d r lated produc ts

This se on edition canc ls an r plac sthe firs edition (ISO 8 0 -4:1 9 ), w hich has be n t ech icaly

r vised with the folowing chang es:

a) normative r fe enc s ha e be n updat ed;

b) me cury the momet er has be n r plac d b the momet er in Clause 4 a);

c) ad itional information isgiven in the not e t o Clause 4 b);

d) combined ins rument desc ibed in Clause 4 d);

e) not es on ins rument pro e ties ha e be n ad ed in Clause 4;

f) in 5.2, “at a given atmosphe ic pr s ur ” has be n ad ed t o r ad “Their p ramet ers ar air

t empe atur an r lative h midity at a given atmosphe ic pr s ur ” ;

g) in 5.3, it has be n ad ed that non-contact the momet ers should not be used;

h) 5.4 has be n chang ed t o ac ount for the def inition of high and low risk of con ensation given in

Cla use 3;

i) desc iption of the proc d r with combined ins rument has be n added in 5.5

j) a r fe enc t o the formula used in Annex A has be n ad ed

ISO 8 0 consis s of the folowing p rt , u de the g ene al title Prep ratio o s te l s ubs trates befr

a plc ation o p ints a d r lated produc ts — Tes ts fr the as s es s ment o s urfc e clea lnes s:

— Part 2 : L b rator y determin tio o chloride o clea ed s urfc es

— Part 4: Guida c e o the es timation o the pro a i t y o c ondens atio prior to p int a plc atio

— Part 5: Meas ur ment o chloride o s te l s urf c es pr p r d fr p intin (io detec tio tu e meth d)

— Part 6 : Ex trac tio o solu le c ontamin nt fr a alys i s — The B resle meth d

— Part 9: Field meth d fr the c onduc tometric dete min tio o wate -solu le s alts

— Part 1 : Field meth d fr the turbidimetric dete min tio o wate -s olu le s ulf te

— Part 12 : Field meth d fr the titrimetric dete min tio o wate -solu le fe ro s io s

The pe formanc of prot ective co tings of p int an r lat ed prod ct a pled t o st eel is significantly

afe t ed b the s at e of the st eel surfac immediat ely prior t o painting The princip l fact ors that ar

k own t o influenc this pe formanc ar as folow s:

a) pr senc of rus an mi scale;

b) pr senc of surfac contaminant , inclu ing salt , d s , oisan gr ases;

c) surfac prof ile

The ISO 8 0 , ISO 8 0 an ISO 8 0 se ies of Int ernational Stan ards ha e be n pr p r d t o pro ide

methods of as es ing these fact ors, w hie the ISO 8 04 se ies pro ides guidanc on the pr paration

methods that ar a ai a le for cleaning st eel subs rat es, in icating the ca a i ities of each in at aining

spe ified levels of cleanlnes

These se ies of Int ernational Stan ards do not contain r commen ations for the prot ective co ting

sy st ems t o be a pled t o the st eel surfac Neithe do they contain r commen ations for the surfac

q alty r q ir ment for spe ific situations even though surfac q alty can ha e a dir ct influenc on

the choic of prot ective co ting t o be a pled an on it pe formanc Such r commendationsar fou d

in othe document such as national s an ards an codes of practic It wi l be ne es ary for the use s

of these Int ernational Stan ardst o ensur that he q alties spe ified ar

— comp tible an a pro riat e b th for the environmental con itions t o w hich the st eel wi l be ex osed

an for the prot ective co ting sy st em t o be used, an

— within theca a i ty of the cleaning proc d r spe ified

The four se ies of Int ernational Stan ards r fe r d t o a o e deal with the folowing aspe t of

pr p ration of st eel subs rat es befor a plcation of paint an r lat ed prod ct :

— ISO 8 0 on visual as es ment of surfac cleanlnes ;

— ISO 8 0 on t es s for the as es ment of surfac cleanlnes ;

— ISO 8 0 on surfac roughnes charact eris ics of blas -cleaned st eel subs rat es;

— ISO 8 04 on surfac pr p ration methods

Each of these Int ernational Stan ards is in turn divided int o separat e p rt

Some paint (but not al ) r q ir dry surfac s w hen being a pl ed t o st eel s ructur s Thin films of

con ensed wat er on st eel surfac s ar mos ly invisible It is the efor important t o ha e a method b

w hich the pro a i ty of con ensation can be es imat ed prior t o the a plcation of p int

Preparation ofsteel substrates before application ofpaints

Part 4:

Thisp rt of ISO 8 0 gives guidanc on the es imation of the pro a i ty of condensation on a surfac t o

be p int ed It ma be used t o es a l sh w hethe con itions at the jo sit e ar suita le for p inting or not

2 Normati ve r eferences

The folowing document , in w hole or in p rt, ar normatively r fe enc d in this document an ar

in ispensa le for it a pl cation F or dat ed r fe enc s, only the edition cit ed a pl es F or u dat ed

r fe enc s, the lat es edition of the r fe enc d document ( inclu ing any amen ment )a pl es

ISO 8 0 , Data element a d inte cha ge frmats — In ormatio inte cha ge — R epr s entatio o dates

a d times

3 Probabi ity of c ondensation

The r lative h midity of the air an the st eel surfac t empe atur ar the b sis for the es imation of

the pro a i ty of con ensation, but the e isno simple rule t o emplo Thesituation iscomplex be ause

the e ar a multitu e of fact ors w hich ha e an influenc on the con ensation an ev p ration of

mois ur , such as

— heat con uctanc of the s ructur ,

— solar radiation on the surfac ,

— flow of ambient air aroun the s ructur , an

— contamination b hygrosco ic subs anc son the surfac

These fact ors sometimes pro oke wet ing or pr vent drying localy on the surfac , e.g w he e the

surfac t empe atur r mains low or t en s t o fal d e t o heat los es or w he e the air be omes q ickly

saturat ed d e t o r d c d ventiation Natural y, the same fact ors sometimes ha e the o p sit e efe t

The efor , any t es r sult should be int erpr t ed with thegr at es car

Unles othe wise a r ed, the st eel surfac t empe atur should g ene aly be at leas 3 °C a o e the de

w-p int w hen p int ar used

NOTE 1 F or paints that are tolerant o moisture on the surface, a temperature diference les than 3 °C might

b ac epta le

Othe t empe atur dife enc sma bespe ified b the p int man factur r or a r ed b the int er st ed

p rties

If the dife enc betwe n the surfac t empe atur an the dew-p int is below or wi fal below the

r q ir d and/ r a r ed minimum, the pro a i ity of con ensation should be conside ed as being “high ”

If the dife enc is a o e an wi r main a o e the r q ir d an / r a r ed minimum, the pro a i ty

of condensation should be conside ed as being “low”

It is imp rtant t o ju g e w hethe a t empe atur dro , sufficient t o cause con ensation, isl kely t o oc ur

d ring the c itical pe iod Ta le 1 ma be used t o help with this det ermination

If the r lative h midity is 8 % or highe , then painting should be ju g ed c iticaly asthe dew-p int is a

ma imum of 2,5 °C awa

If the r lativ e h midity is high ( 92 % or dew-p int 1,3 °C awa ), painting should only be conside ed

if con itions can be confidently ex e ted to r main s atic or improv e d ring the a plcation an

drying pe iod

NOTE 2 This period is usualy ap ro imately 6 h

If the r lative h midity is a p r ntly satis act ory (for ex mple, 80 % or dew-p int 3,4 °C awa ), the

environmental con itions o e an a pro riat e time pe iod ahead, oft en a out 6 h, should s i l be

conside ed in orde t o asc rtain that dew con itions wi not oc ur

The folowing ins rument should be used, although ins rument othe than those desc ibed ma be

used pro ided that they ha e an eq iv lent or gr at er ac uracy

a) F or air t empe atur measur ment , the momet ers ac urat e t o ± ,5 °C

b) F or air h midity measur ment , any of the fol owing ins rument

1) Aspirat ed psychromet ers an w hirl ng ( lng) hy gromet ers, inclu ing ta les for calculation of

h midity ( e ISO 46 7-1 an ISO 46 7- 2, r spe tively), ac urat e t o ± % RH

NOT 1 T e aspirated psychrometer is the reference instrument ty e ac ording to the World

Mete rolo ical Org nization (WMO)

2) Digital ele tronic hygromet ers b sed on measur ment of ca acitanc chang e of polyme f ilms,

ac urat e t o ± % RH an ca a le of o e ating at any r lative h midity in the rang e 0 % RH t o

1 0 % RH an at any t empe atur in the rang e −40 °C t o + 0 °C

3) Digital ele tronic hygromet ers b sed on measuring the r sis anc chang e in a salt bridg e,

ac urat e t o ±2 % RH an ca a le of o e ating at any r lative h midity in the rang e 0 % RH t o

9 % RH an at any t empe atur in the rang e 0 °C t o 7 °C

Due t o the sensitivity t o hy st er sis, ele tronic dew p int ga ug esshould be han led ac ording t o

man factur r spe ifications and the pro a i ty for hy st er sis should be pr vent ed t o maintain

cor e t r sult The pro e should, for ex mple, not be ex osed t o larg e t empe ature /h midity

v riations C n ensation on the sensor surfac ma give ofset r ading in the orde of 1 %, for

some sensor ty es las ing for day s

NOT 2 Hy grometer are sensitive to contamination; salts or other substances adsorbing moisture wil

cause er one us re dings

NOT 3 Hygromet er req ire calibration; some ty es, as sensor using a salt bridg e, more oft en than other

c) F or surfac t empe atur measur ment , digital ele tronic the momet ers, ac urat e t o ± ,5 °C

Ma netic surfac the momet ers ma be used pro ided that they ha e the r q ir d ac uracy an

ar lef on the surfac for sufficient time t o r ach the surfac t empe atur

d) Digital ele tronic ins rument measuring air t empe atur , surfac t empe atur an h midity,

ca a le of calculating the dew point, as wel asthe dife enc betwe n the air t empe atur and the

dew p int

5.1 Using the ins rument desc ibed in Clause 4 a) an Clause 4 b), measur e the air temperatur e to the

near es 0,5 °C an the r elative h midity

5.2 C lculate the dew-p int , which is a logarithmic fu ction of the v pour pr es ur e at the actual

temper atur e There are ta les or charts fr om which the dew-p int can be dete mined Their p ramete s

ar e air temperatur e and relative h midity at a g iven atmosphe ic pres ur e Such a ta le is g iven in

A nnex A C mmercial dew-p int calculators of suficient ac uracy ma y also be used

Table 1 — Temperature drop ne ded for co densatio to oc ur, as a functio of the relative

h midity

NO E The f ig res are me n values for air temperatures fom 0 °C to 3 °C For a given air temperature, more a curate

fig res c n be obtained f om An ex A

5.3 Using the instrument desc ibed in Clause 4 c), measure the s e l surfac temperatur e Take at

leas one temperatur e measur ement for eve y 1 m

2

of the surfac and ado t the lowes measured

temper atur e in calculating the dew p int Non-contact the momete s (IR-the momete s) should not be

used to measur e surfac temperatur e due to inte ferenc with the surrou ding air

When sele ting locationsfor t empe atur measur ment , any v riation in the thick es of the st eel an

the efe t of shadeshould be conside ed

NOTE S me digital electronic hy grometer also me sure the air temperature an calculate the dew-point

temperature automaticaly

5.4 Es imate the minimum surfac temperatur e (a o e the dew-p int) that is ne ded to o tain a “ low”

risk of condensation u de the prev i ng environmental con itions, se Clause 3

5.5 If using a combined ins rument desc ibed in Clause 4 d), p ints 5.1 to 5.4 shal be r eplac d b the

folowing pr oc d re:Read the dew p int , calculateor r ead the difer enc betwe n the dew p int an the

surfac temperatur e an che k if risks for con ensation ar e considered “low” or “high ”, se Clause 3

6 Test r eport

The t es r p rt hal inclu e the fol owing:

a) a r fe enc t o this p rt of ISO 8 0 , i.e ISO 8 0 -4;

b) the dat e of car ying out the measur ment ( inclu ing the da an hour), ex r s ed in ac ordanc

with ISO 86 1;

c) a desc iption of the ins rument used;

d) thecalculat ed dew-p in

e) themeasur d st eel surfac t empe atur ;

f) thedife enc betwe n the st eel surfac t empe atur an the dew-p int ;

g) theminimum t empe atur dife enc ne ded t o a oid con ensation;

h) any u usual featur s (anomales)o se ved d ring the t est ;

i) an es imat e of the pro a i ity of con ensation as being “high ” or “low”

A nne x A

Ta le A.1 gives the dew-p int t empe atur , t

d, as a function of the air t empe atur , t, an the r lative

h midity, RH

The folowing ins ructions ar given for the use of Ta le A.1

— E t er the ta le at v lues ofr lative h midity w hich s rad lethe actual (measur d) v lue

— E t er the ta le at v lues ofair t empe atur w hich s rad le the actual (measur d) v lue

— Identify the cor espon ing four int erse tion v lues of dew-p int t empe atur , make a lnear

int erp lation in two st epsand rou d of t o 0,1 °C

The v lues given in Ta le A.1 ar comput ed from the folowing formula, de ived from an a pro imat e

formula known as the Ma n s formula

NOTE As can b se n from the formula, t is a comparatively simple fu ction of two varia les, t an RH T is

fu ction therefore len s itself to calculations by use of an ordinary s ientif ic pro ramma le calculat or Such a

calculat or, inclu ing its pro ramme, can b re arded as b ing eq ivalent t o the ta le It is su erior t o the ta le in

that it presents without interpolation a direct re ding of the dew-point t emperature In ad ition, a smal

pocket-ty e calculat or is usual y e sier to manip lat e on site than a comprehensive ta le covering several A 4 format

pa es To make sure that he calculator is properly pro rammed, p t in an ta ulated pair of t-an RH-values an

compare the result with the cor espon ing value of t in the ta le

Table A.1 — Dew-point t emperature t

d

as a functio of the air temperature t and the relative

h midity RH at 1 1 kPa air pres ure

Table A.1 (c ontin ed)

Table A.1 (c ontin ed)

Table A.1 (c ontin ed)

Table A.1 (c ontin ed)

Table A.1 (c ontin ed)