Pull-off Adhesion Testers
The PosiTest AT Pull-Off Adhesion Tester measures the force required to pull a specified test diameter of coating away from its substrate using hydraulic pressure. The pressure is displayed on a digital LCD and represents the coating's strength of adhesion to the substrate.
Automatic
Memory and Reporting Features
- Internal memory stores maximum pull-off pressure, rate of pull, test duration, and dolly size for 100,000 pulls in up to 1,000 batches
- Record the results as pass/fail and the nature of fracture - cohesive, adhesive, and glue failures
- Wirelessly connect to your smart device using our free PosiTector App (Apple iOS and Android)
- WiFi technology wirelessly communicates with PosiSoft.net, downloads software updates, and allows access to stored measurement data using standard web browsers (see WiFi Features for full details)
- PosiSoft USB Drive - stored readings and graphs can be accessed via USB using universal PC/Mac web browsers or file explorers. No software required
- Compatible with PosiSoft Desktop, PosiSoft.net, and PosiTector App (Apple iOS and Android) software
Recording the Nature of the Fracture
Upon completion of a pull-off test, the dolly and coated surface should be examined. In addition to pull-off force, many National and International standards such as ASTM D4541 and ISO 4624 require the nature of the fracture to be recorded.
- Cohesive fracture: fracture occurs within a coating layer (same coating on dolly face and coated surface).
- Adhesive fracture: fracture occurs at the interface between layers (coating on dolly face differs from the surface).
- Glue failure: visible separation of the glue from itself, the coating or dolly (no coating visible on the dolly face).
The cohesive and adhesive fracture visual analysis can be recorded using the PosiTest AT-A's keypad or touch screen display. Alternatively, the information can be reported using the PosiTector App.
Fractures are visually estimated and recorded as a percent of each. The two-layer example below illustrates a cohesive fracture within coating layer 1 and layer 2 (visually estimated at 50% each). Recorded results are included in reports.
The PosiTest AT-A can record fracture information for up to five layers. For full details and examples see Visual Analysis and Recording of Test Results.