ASTM D – 11, “Standard Test Methods for Field Measurement of Surface locations and the arithmetic mean determined, Method C—A composite plastic. ASTM D – 11 Standard Test Methods for Field Measurement of Surface Profile of Blast Method C—A composite plastic tape is impressed into. ASTM Test Methods determined by averaging a given number (usually 20) of the Hold the gage by its base and Method C: committee at this time is Testex.
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This can be discussed and agreed upon at the pre-construction conference. Inspection Instruments Pipeline Coatings — Volume 2: The s4417 of this peak-valley pattern in the surface effectively increases the surface area, providing an anchor for the coating system. Naturally, the ability to generate reliable data between users employing different instruments, as well as the ability of one user to generate repeatable data using a single instrument, must be assessed.
Difference in Surface Profile Measurements: ASTM D Method B vs CKTA University
A plan is currently under development for an interlaboratory study on the various methods used to extract and analyze samples, as described in the method. There are additional techniques suitable for laboratory use not covered by these test methods. Conversely, concrete is a heterogeneous substrate.
In response to these and other issues, Subcommittee D Many equipment manufacturers have developed loading fixtures with a larger surface area i. As confirmed by a research paper presented at the SSPC National Conference, 3 the adhesion values generated by the various test devices can vary considerably. Methods of generating various peak densities are described in asfm articles, and are based on abrasive size, shape, hardness and other factors.
Pull-Off Adhesion of Coatings on Concrete As stated above, the original version of D published in did not distinguish between testing the pull-off strength of coatings applied to steel versus concrete surfaces.
This method encompasses only one surface characteristic: The decision whether to score has been left to the parties requiring the testing and those conducting it. There are many revisions being considered by the subcommittee. Measuring Surface Roughness of Abrasive Blast Cleaned Steel The industrial protective coatings industry has long recognized the importance of surface profile depth generated by abrasive blast cleaning and some power tools as a means to increase surface area and improve the adhesion of the coating to atsm underlying substrate.
The base of the instrument rests on the peaks of the surface profile while the cone-shaped point projects into the valley. Surface Chloride Extraction and Analysis The protective coatings industry has long recognized the potential consequences of coating over soluble salts i. Both the structure and the coating system protecting the metnod will move while in service. The pull-off method is widely used by coatings manufacturers, specifiers, inspectors and coating specialists.
The specified minimum pull-off strength must also be carefully considered. In d44417, a plan jethod developed to conduct a comprehensive interlaboratory study involving six coatings, six laboratories and five types of adhesion testing equipment.
Differences in Surface Profile Measurements: ASTM D4417- Method B vs. Method C
Tests are done on smooth surfaces, and are not designed to address rough or porous surfaces like concrete block or brick, which would be substantially more difficult to clean without d44417 tools and methods. The tape selected is based on the anticipated or specified surface profile depth.
Currently, this subcommittee has eight task groups that are working on 13 ASTM standards, four f4417 which are proposed standards and nine of which are existing standards that have been slated for revision or renewal, or that have been recently published and require the development of precision and bias statements through interlaboratory research initiatives.
The subcommittee develops and maintains standard test methods, practices and guides relating to the performance, evaluation, specification, application and proper use of industrial protective coatings.
Paint grade replica tape is used to measure surfaces containing a profile from 1. Typically, the higher the coating thickness the greater the surface profile depth.
D44117, Method B and Method C are the most commonly used, so that is what we will be focusing on. Scoring the Coating Cutting scoring through the coating prior to the attachment of the loading fixture has long been a controversial issue. Testing consists of securing a loading fixture to the coating surface with an adhesive. For Method C, there are various ranges of replica tape that can be employed. See Figures 45 and 6. Once the surface profile pattern has been replicated into the tape, it is removed from the surface and placed in a special spring tension anvil micrometer.
Coating manufacturers may also consider these requirements to improve the performance and the service life of the coatings they supply.
ASTM WKDraft Practice for Assessing the Concentration of Soluble Chlorides on Adtm Substrates, provides procedures for four methods of extracting a surface sample, four procedures for analyzing the collected sample for soluble chlorides, and one procedure for analyzing a collected sample for total dissolved salts conductivity.
Industrial Protective Coatings by William D.
While there is current activity on all 13 standards, this article focuses on five major tasks being undertaken by the subcommittee at this time. The average surface profile depth is read from the micrometer dial in mils or micronsafter the micrometer has been corrected for the thickness of the polyester backing material. In response to a growing demand, a number of coatings were developed and advertised as being resistant to graffiti, or easily cleaned of graffiti.
Models from a few gage manufacturers are available that conform to this standard. During abrasive blast cleaning, the mass of the abrasive and the velocity of the abrasive movement created by compressed air generates kinetic energy the abrasive can reach speeds of over miles per hour as it exits the blast nozzle.
So, in effect the reading on the micrometer or the RTR from the replica tape represents several peaks and valleys, while the depth micrometer does not.