EN 14127:2011

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Zerstörungsfreie Prüfung - Dickenmessung mit UltraschallEssais non destructifs - Mesurage de l'épaisseur par ultrasonsNon-destructive testing - Ultrasonic thickness measurement19.100Neporušitveno preskušanjeNon-destructive testingICS:Ta slovenski standard je istoveten z:EN 14127:2011SIST EN 14127:2011en,fr,de01-julij-2011SIST EN 14127:2011SLOVENSKI
STANDARD
EUROPEAN STANDARD NORME EUROPÉENNE EUROPÄISCHE NORM
EN 14127
February 2011 ICS 19.100 Supersedes EN 14127:2004English Version
Non-destructive testing - Ultrasonic thickness measurement
Essais non destructifs - Mesurage de l'épaisseur par ultrasons
Zerstörungsfreie Prüfung - Dickenmessung mit UltraschallThis European Standard was approved by CEN on 25 December 2010.
CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management Centre has the same status as the official versions.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre:
Avenue Marnix 17,
B-1000 Brussels © 2011 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 14127:2011: ESIST EN 14127:2011

Corrosion in vessels and piping . 22A.1General. 22A.2Measurement of general corrosion . 22A.2.1Instrument . 22A.2.2Probes . 22A.2.3Setting of the instrument . 22A.2.4Measuring . 23A.3Measurement of corrosion with pitting . 23A.3.1Instrument . 23A.3.2Probes . 23A.3.3Setting of the instrument . 23A.3.4Measuring . 23Annex B (informative)
Instrument settings . 29Annex C (informative)
Parameters influencing accuracy . 31C.1Parameters influencing accuracy . 31C.2Methods of calculation . 33Annex D (informative)
Measuring technique selection . 36Bibliography . 40 SIST EN 14127:2011

Mode 1 Mode 2 Mode 3
Mode 4
Key A transmit/receive probe Dtransmission pulse indication A1 transmit probe E1 to E3back-wall echoesA2 receive probe Finterface echoA3 dual element probe Gdelay pathB test object Hreceived pulseC sound path travel time Figure 1 — Measurement modes SIST EN 14127:2011

is the thickness; v
is the sound velocity; t
is the measured time; n
is the number of transits through the test object (see Figure 1). SIST EN 14127:2011

Key A transmit/receive probe B test object C sound path travel time D transmission pulse indication E1 to En backwall echoes Figure 2 — Instrument setting for mode 3 7.3 Check of settings Checks of the settings of a thickness measuring system shall be carried out with a reference test piece: a) on completion of all measurement work; b) at regular intervals during the work session; c) if probes or cables are changed; d) if material types are changed; e) if the material or equipment temperature changes significantly; f) if major operating controls are adjusted or considered altered; g) at other intervals as directed by specific procedural instructions. SIST EN 14127:2011

1 mm at v = 5 920 ms-1;
 Zinc
20 µm at v = 4 100 ms-1;  Actual thickness 1 mm + 20 µm = 1,02 mm; )(()s738,1100410209205101763−−−=×+× (2) mm029,19205738,17=×− (3)  Measured thickness
1,029 mm;  Deviation
0,009 mm. Cladding thickness can be measured. Measurement accuracy depends on the same parameters as the measurement of the base material. 8.1.4 Non-metallic coating When measuring through coatings, errors will occur as a result of the differing sound velocities of the coating and the test object. For example, with the instrument calibrated for steel:  Steel
1 mm at v = 5 920 ms-1;  Paint
100 µm at v = 2 100 ms-1 (this is a generic value and not indicative of a type);  Actual thickness
1 mm + 100 µm = 1,1 mm; )(()s165,21002101009205101763−−−=×+× (4) mm282,19205165,27=×− (5)  Measured thickness 1,282 mm;  Deviation
0,182 mm. It can also be difficult to obtain the desired measurement if the coating material is:  similar in acoustic properties to the test piece material;  of a significant thickness compared to that of the test piece. SIST EN 14127:2011

Key A probe B coating or plating C increased sound path through coating D sound path travel time E metal Figure 3 — Increased sound path through coating 8.1.5 Geometry 8.1.5.1 Parallelism The opposite walls of the test object (piece) should be parallel within ± 10° otherwise measurement can be difficult or erroneous. This is due to deformation or lack of back-wall echoes due to “spatial integration”. 8.1.5.2 Curved surfaces In this case the small contact surface area between the probe and the test piece can reduce the effectiveness of the couplant and in turn the signal quality. The probe shall be aligned to the centre of curvature of the test object. These factors will affect measurement performance by giving poor acoustic transmission and repeatability. 8.1.5.3 Concave and convex scanning surfaces The probe face shall always allow adequate coupling. Small radii require a small probe diameter. 8.1.5.4 Range of thickness Accurate measurement depends on material homogeneity throughout its thickness. Local or general changes of composition will result in changes of velocity compared to that of the material of reference blocks and therefore subsequent measurement errors. SIST EN 14127:2011

is the wavelength; f
is the probe frequency; v
is the sound velocity. Probe frequency also dictates the maximum thickness that can be measured. A high frequency probe will have less penetrating power than a lower frequency one. Consideration should be given to the type of material in question as this also has an affect on measuring range. The selection of probe frequency is controlled by the range of material thickness to be measured and also by the type of material. The measuring system shall be selected such that its measuring range properly covers the thickness of interest. In the case of an A-scan instrument (type 5.1 c)) the range setting shall be such that it suits the desired resolution at that range without switching ranges. It is recommended that instrument settings are checked at both ends of the thickness range to be measured. SIST EN 14127:2011

To minimise the risk of error, setting of the instrument shall be carried out in the same plane as the measurement. 9.4 Attenuation Acoustic attenuation is caused by energy loss through absorption (e.g. rubber) and by scattering (e.g. coarse grains). This effect can cause a reduction of signal amplitude or a signal distortion. Castings generally exhibit attenuation through absorption and scattering resulting in lack of or erroneous readings. High attenuation through absorption alone may be found in plastics. 9.5 Surface conditions 9.5.1 General Poor attention to surface conditions will result in either inability to obtain measurements or erroneous measurements. SIST EN 14127:2011
...