KTA Podcast #5: Surface Profile Measurement - Replica Tape vs Digital Depth Micrometer

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This podcast covers measuring surface profile and discusses multiple methods for measuring profile. It also covers some of the complications that may occur when using both methods on the same job. Featuring a variety of hands on demonstration and instrumentation use. KTA Chief Operating Officer, Bill Corbett, addresses the digital profile reading equipment. Bill is active in ASTM D146, which is the committee that develops the standards for measuring surface profile. KTA Coatings Group Operations Manager, John Todd, discusses replica tape. John is active in the NACE committees that develop their standard practices for profile measurement.

Пікірлер: 8

@giuseppesantagata2339 6 жыл бұрын

Very useful lesson. But I would like to insert some comments: 1) Regarding potential reading error using replica tape if rubbed over dirt, this problem is valid also for the digital depth micrometer (if in the valley there is some abrasive residue, dust, etc.); - Normally before to place the tape over a blast cleaned surface the involved surfaces are fine blowed up or cleaned with a dry soft brush just before to place the tape: the same procedure will be adpted using the digital depth micrometer, this means that probably if you have to use a clean brush to clean the reading area, you are obligated to use both hands also with this method. 2) On my point of view when you read the profile on the replica tape using the spring micrometer you read the max peak present in the rubbed circled area not "many peaks combined" as you affirm. 3) another important tip: the digital depth micrometer cannot be used everywhere due to its dimension. The tape instead can be placed also in limited areas like internal flange of small anglebar, etc. I am sorry for my poor english I hope is clear what I mean. Regards Giuseppe Santagata

@CoatingsTalk 6 жыл бұрын

Great “vs” topic to cover!

@rajivnjotunindia 6 жыл бұрын

Good topic to cover and discuss

@ktatator 5 жыл бұрын

Thank you, we're glad you enjoyed the topic.

@rockystudios3818 6 жыл бұрын

I have a question here. For testex tape what will be the maximum surface temperature in which it can be used. Because the higher the surface temperature the foam (Milan) used in testex tape can be affected or compressed easily due to heat and give a imperfect reading

@ktatator 5 жыл бұрын

Rocky - thanks for your question. The Testex website states: Press-O-Film HT is formulated for better performance at the high temperatures (above 140°F or 60° C) encountered in the most challenging environments. While stable at 140°F (60° C), the current film starts to gradually soften above that temperature. The new formulation adds a 12°F (6°C) safety margin. Why has Testex changed the formula for Press-O-Film? “Old formulation” Press-O-Film softened at temperatures above 140 °F (60 °C). On the face of it, this would seem a safe operational upper limit. The highest recorded temperature on Earth is only 136 °F (58 °C) and the Threshold of Pain is less, approximately 125 °F (50 °C). Further, the maximum recommended temperature for application of many coatings is about the same as the Threshold of Pain. While it is difficult to imagine using replica tape at temperatures above 140 °F (60 °C) it is, however, possible to imagine storing the tape at those temperatures, especially if the product is kept in a closed container (specifically, a car) in direct sunlight on a very hot day. Here, temperatures can get well above outdoor-ambient. Press-O-Film HT’s new formulation adds 12 °F (6 °C) to the product’s softening point, a margin of safety that can be important to inspectors in extreme - and, especially, in remote - locations. In Testex’ internal testing even the old formula replica tape showed no hint of collapse after 3 hours’ at 140 °F (60 °C) temperatures, so brief exposure to even very hot environments probably need not be a source of concern, however, for safety, exposure to temperatures above 152 °F (66 °C) should never be permitted. Replica tape should always be stored at or below outdoor-ambient temperatures. Long-term storage should be at room temperature, 77 °F (25 °C), or less. The tape itself provides a record of its own thermal history. Un-compressed X-Coarse grade tape should have a thickness between about 5.0 and about 6.0 mils (about 125 and about 155 μm). Thermal collapse will cause it to be less.

@rockystudios3818 5 жыл бұрын

@@ktatator I thank you for the broad understand and knowledge sharing

@michaelh7770 5 жыл бұрын

Would reviewing surface profilometers in this same podcast be reasonable? Unfortunately, the Digital Depth micrometer doesn't fit inside grit-blasted tubes.