ASTM D7091 PDF
This standard is issued under the fixed designation D ; the number 1 This practice is under the jurisdiction of ASTM Committee D01 on Paint and. Related. In nearly the same timeframe, the version of ASTM D, “Standard Practice for Nondestructive Measurement of Dry Film Thickness of. ASTM D describes three operational steps that must be performed prior to coating thickness measurement to help assure the reliability of.
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Appendix 7 was added to accommodate pipe coaters that need to determine coating thickness conformance on non-flat or non-plate areas, including smaller pipe sections on a cart or rack and longer pipe spools.
The BMR is the effect of substrate roughness on a coating thickness gage.
Contained a minimum gage accuracy requirement to qualify for use. Contained 6 appendices Contains 8 appendices. Satm magnitude of nonconforming thickness assessed by obtaining spot measurements in eight equally spaced directions radiating outward from the nonconforming area. While the gage may be out of tolerance by 0. This section lists the items to report when documenting dry film thickness data, including: A one-point or two-point accuracy verification procedure can be performed; typically, the two-point verification provides greater accuracy.
Addressed measurement of coatings d701 steel only. As a result, obtaining single-point measurements may not accurately represent the actual coating system thickness. Change is never easy…. The gage should be veri? Also, uncoated shims of flat plastic sheet with assigned values traceable to a national metrology institution.
SSPC-PA 2 contains three definitions that are critical to understanding this next area of discussion. If a non-conforming area is identified, spot measurements are asfm at 5-foot intervals in eight equally spaced directions radiating outward from the nonconforming area as shown in Figure 13 below.
Measuring Coating Thickness According To SSPC-PA2 – Update KTA University
Leave a Reply Cancel reply Your email address will not be published. If necessary, the gage should be adjusted as described in 7. The two documents are designed to be used in conjunction with each another. ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentioned in this standard. In the edition, if spot or area measurements were out of conformance, each square-foot area coated during the work shift had to be measured, and nonconforming areas had to be demarcated.
To guard against measuring with an inaccurate gage, SSPC-PA 2 requires that gage accuracy be verified at a minimum at the beginning and end of each work shift according to the procedures described in ASTM D These gages are categorized as “magnetic pull-off” and “electronic.
This procedure also verifies that the probe configuration will accommodate the edge configuration before acquiring coating thickness data. The Table enables the specifier to select from five different restriction levels related to spot and area measurements.
Measuring Dry Film Coating Thickness According to SSPC-PA 2
If shims are selected to verify gage accuracy, they should be placed on a smooth steel plate zero-plate. For example, asm the specification requires 3 mils dry film thickness and the coating manufacturer does not provide any additional information regarding a recommended thickness range, then by default the specified range is established as 2.
The manually operated gages may be susceptible to human error caused by inadvertently turning the dial wheel past the point at which the magnet pulls from the surface, yielding a false low measurement.
The minimum value of ? All of the area within five feet of any non-compliant spot measurement is considered non-compliant. The above article was very informative and useful, thanks for sharing it.
Verification of gage accuracy is typically performed using certified coated thickness standards for Type 1 or Type 2 gages or certified shims Type 2 gages.
The number of spot measurements along the edge will vary depending on the total length of the coated edge. Verification of gage accuracy is typically performed using certified coated thickness standards for Type 1 or Type 2 gages or certified shims Type 2 gages. Correction for Base Metal Reading if acquired. Within each area, five randomly v7091 spots are selected. The scale is not linear. The user aatm consult the manufacturers instructions regarding the use of coating thickness gages on these types of coatings.
If a large number of measurements are asttm obtained, the user may opt to verify gage accuracy during measurement acquisition for example, d791. The certified shim should be placed onto a smooth, uncoated metal surface to remove any effect of the surface roughness during this process. This enables the specifier to select from five different restriction levels related to spot d70911 area measurements. All references to the frequency of measurements were removed from the ASTM standard.
If no Restriction Level is specified, then the default is Level 3, which is based on the version of SSPC-PA 2 what many users of the standard have become accustomed to. Spot measurement definition was expanded. Verifying accuracy of Type 2 gage using a certified shim. Use of the gage outside of this range may generate false coating thickness measurements and may damage the instrument.
This inverse relationship is re? It is important to note that both documents address the measurement of the DFT of coatings on ferrous and non-ferrous metal substrates.