DeFelsko PosiTest AT-A Automatic Pull-Off Adhesion Tester

Automatic pull-off adhesion testing with fracture records

The DeFelsko PosiTest AT-A is an automatic hydraulic pull-off adhesion tester that measures how well a coating is bonded to metal, wood, concrete and other rigid substrates. An electronically controlled pump applies smooth, continuous pressure, which greatly reduces operator effort and the risk of influencing the pull. Single-use aluminium dollies are glued to the coating, pulled off, and kept as a permanent record. The tester is calibrated and certified to +/-1% accuracy with a NIST-traceable load cell, and DeFelsko lists conformity to ASTM C1583, D4541, D7234 and D7522, ISO 4624 and ISO 16276-1, EN 1542 and EN 12004-2 and AS/NZS 1580.408.5.

Technical specifications

Resolution is 0.01 MPa (1 psi) and accuracy is +/-1% of full scale. Units can be psi, MPa, N per square mm or newton. Maximum pull-off pressure by dolly size is 96 MPa for 10 mm, 50 MPa for 14 mm, 24 MPa for 20 mm and 3.8 MPa for 50 mm dollies; custom 10 mm and 14 mm dollies are available and fit the 20 mm stand-off. The enclosure meets or exceeds IP65 and the built-in lithium-ion battery performs more than 250 tests per charge, with a USB-C port that charges and powers the instrument at the same time.

Memory, reporting and ordering

The AT-A stores maximum pull-off pressure, rate of pull, test duration, pressure against time, dolly size, pass or fail, nature of fracture and notes for 100,000 pulls in up to 1,000 batches. The operator can record cohesive, adhesive and glue failures as estimated percentages for up to five layers, which standards such as ASTM D4541 and ISO 4624 require alongside the pull-off value. Pull rate, pull limit and hold time are user adjustable. Data transfers by USB, WiFi to PosiSoft.net and Bluetooth to the PosiTector app for photos, notes and PDF reports. Each kit includes the tester, charger, dollies, abrasive pad, cutting tool, glue with mixing sticks and palettes, cotton swabs, USB cable, PosiSoft software, a Certificate of Calibration traceable to NIST and a hard-shell case with a two-year warranty. A heavy-duty Pelican case is available by adding -P to the code, and optional conversion kits allow a model to use another dolly size.

Choosing automatic or manual and the dolly size

DeFelsko also lists the manual PosiTest AT-M with codes ATM20, ATM50, ATM50C and ATM50T; it uses a hand pump with a pull rate indicator and stores up to 200 pulls. The automatic AT-A suits inspectors who want a controlled pull rate and a full electronic record. Select the dolly size from the expected bond strength: the 20 mm dolly for high-strength coatings on metal, the 50 mm dolly for weaker coatings on wood, concrete or plastic, the C1583 version for concrete overlays and the tile version for cementitious adhesives. See all portable test and measurement instruments.

Documents and quotation

The attached DeFelsko datasheet covers both the automatic and manual models. Please confirm before ordering the order code and dolly size, whether the Pelican case or a conversion kit is required, the substrate and the standard you inspect to, and send them with your enquiry so the code can be checked against the manufacturer documentation.