ASTM D4417-19 pdf free download.Standard Test Methods for Field Measurement of Surface Profile of Blast Cleaned Steel.
1.1 These test methods cover the description of techniques for measuring the profile of abrasive blast cleaned surfaces in the field. There are other techniques suitable for laboratory use not covered by these test methods.
1.2 Method B may also be appropriate to the measurement of profile produced by using power tools.
Note I — The Method 11 procedure in this standard was developed for use on flat surfaces. Depending on the radius of the surface, the results could have greater variability with lower values and averages.
1.3 SSPC standard SSPC-PA 17 provides additional guidance for determining conformance with surface profile requirements.
1.4 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.
4. Summary of Test Method
4. 1 The methods are:
4. 1.1Method A- The abrasive cleaned surtace is compared to commercial replicas of various surface proble depths prepared by different blast media and the range determined. The geometry of the specific abrasive cleaned surface can also be observed. This does not apply when combinations of blast media, such as shot and grit, are used.
4. 1 .2 Method B—The depth of profile relative to the peaks is measured using a fine-pointed probe at a number of locations and the average of the maximum peak-to-valley distances (or alternatively, the average peak-to-valley distances) is determined.
4.1.3 Method C—A composite plastic tape is impressed into the blast cleaned surface forming a reverse image of the profile. The average maximum peak-to-valley distance can be measured using a suitable thickness gage. The average of these distances can be determined from a group of measurements. Specially designed optical readers can also determine the peak density from the tape replica.
4. 1.4 Method D—A trace measurement is taken by a portable stylus surface roughness instrument to obtain maximum peak-to-valley distance. The average of these distances is determined from a group of five traces. These devices can also determine peak count information.ASTM D4417 pdf download.