PosiTest AT-A Automatic Pull Off Adhesion Tester

The Positest AT-A Automatic Adhesion Tester measures the force required to pull a specified test area of coating away from a substrate using hydraulic pressure. An electronically controlled hydraulic pump automatically applies smooth and continuous pull-off pressure. The pump greatly reduces user effort and the risk of influencing the pulling process.

The AT-A's built-in rechargeable battery performs over 200 tests per charge. The supplied AC adapter / charger allows you to continue testing with AC power while the battery recharges.

The AT-A is features an environmentally sealed enclosure. It is weatherproof, dustproof and shockproof. Meeting or exceeding IP65 rating.

Features

• Select from four Stand-offs - 20 mm, 50 mm, 50x50 mm Tile and 50 mm C1583
• Environmentally sealed enclosure – weatherproof, dustproof and shockproof - meets or exceeds IP65
• Inexpensive, single-use dollies eliminate cleaning for re-use and can be kept as a permanent record
• Self-aligning aluminum dolly enables accurate measurements on smooth or uneven surfaces
• 10, 14, 20 or 50 mm dollies maximize capability and measurement resolution across a wide range of bond strengths
• Calibrated and certified to ±1% accuracy using a NIST traceable load cell
• Conforms to international standards including ASTM C1583/D4541/D7234/D7522, ISO 4642/16276-1, BS EN 12004-2, AS/NZS 1580.408.5 and others
• Electronically controlled hydraulic pump automatically applies smooth and continuous pull-off pressure. Greatly reduces user effort and the risk of influencing the pulling process
• Impact and scratch resistant color touch screen with keypad for operation with or without gloves
• Built-in rechargeable battery performs over 200 tests per charge. Continue testing with AC power while the battery recharges.
• Rubberized, shock absorbing grips provide a stable, skid-resistant footing
• 10, 14, 20 or 50 mm dollies maximize capability and measurement resolution across a wide range of bond strengths. Maximum pull-off pressure by dolly size:
  • 10 mm: 14000 psi (96 MPa)
  • 14 mm: 7000 psi (50 MPa)
  • 20 mm: 3500 psi (24 MPa)
  • 50 mm: 560 psi (3.8 MPa)
• User selectable measurement units: psi (pounds per square inch), MPa (Megapascal), Nmm2 (Newtons per millimeter square) or Newton (force)
• User adjustable pull rate, pull limit and hold time
• Rotating display for horizontal and vertical use
• Software Updates via web keep your instrument current

Model Comparison

* Optional 20mm/50mm/50 mm C1583/50 mm Tile Conversion Kits allow each model to be used with alternative dolly sizes. Custom 10 and 14 mm dollies are available for special applications (compatible with 20 mm stand off).

ATA Self-Alignment Feature

Unequal pulling force during testing caused by uneven adhesive bond lines and coating surfaces can result in random, unexplainable readings. To obtain more repeatable and meaningful adhesion measurements, it is imperative that the pulling force applied to the test dolly is uniformly distributed over the surface being tested.

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Both the PosiTest AT-M manual and PosiTest AT-A automatic models compensate for misalignment. The self-aligning, quick-coupling actuator and spherical articulating dolly head enable uniform distribution of the pulling force over the surface being tested, preventing a one-sided pull-off

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
• 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 wit PosiSoft Desktop, PosiSoft.net and PosiTector App (Apple iOS and Android) software solutions

PosiTector App Features Add images and notes using the camera or keyboard Create customized, professional PDF reports Share, backup, synchronize and report measurement data Auto-pairing Bluetooth (BLE) connection

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Touch Screen Display

Use the touch screen to interact with menu options. Swipe horizontally to navigate between views or vertically to move between batch readings. Alternatively, the keypad can be used for navigation and selection.

User adjustable dolly size, pull rate, pull limit and hold time.

Batch summary provides an at-a-glance review of test results

View test parameters and reading results. Reading is recorded as pass or fail based on set test parameters. The pass/fail results can be revised.

Notes can be added for each reading

Include a note for a batch (group) of readings

Record the nature of failure - cohesive, adhesive and glue failures

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 surface). Glue failure: visible separation of the glue from itself, the coating or dolly (no coating visible on the dolly face).

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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.

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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.

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Examples
(based on above five layer illustration)

Optional Accessories

Dollies Loading fixtures, stubs for adhesion testing. Choose from the following sizes and quantities: Size Quantity Order Code 10 mm 10 DOLLY10 14 mm 10 DOLLY14 20 mm 10 DOLLY20 50 mm 4 DOLLY50

Dolly Multipacks Larger quantity of dollies at a reduced cost. Select from the following multipacks Size Quantity Order Code 10 mm 100 DOLLY10APK100 14 mm 100 DOLLY14APK100 20 mm 100 DOLLY20APK100 50 mm 50 DOLLY50APK50

20 mm Conversion Kit Order Code: AT20KIT Interchangeable stand-off allows a PosiTest ATM20 or ATA20 to pull 10, 14 and 20 mm dollies Ideal for high bond strength finishes such as coatings on metal Includes 20 mm stand-off, 20 mm hole saw and 20 mm aluminum test dollies (20)

50 mm Conversion Kit  Order Code: AT50KIT Interchangeable stand-off allows a PosiTest ATM20 or ATA20 to pull 50 mm dollies Ideal for lower bond strength finishes such as coatingson wood, concrete and plastic Larger surface area of dolly provides improved low range precision and repeatability Includes 50 mm stand-off, 50 mm hole saw and 50 mm aluminum test dollies (12)

Drilling Template for 50 mm Dollies  Order Code: TMPLTAS Drilling template and drill bits to isolate test area, ideal for thicker coatings on concrete Includes (10) drill bits 5/32" (4 mm)

Glue Kit Order Code: ATADHESIVEKIT ResinLab EP11HT 2-Part Epoxy Additional glue, mixing sticks, palettes and cotton swabs

50 mm x 50 mm Tile Accessory Kit - AT50TKIT Interchangeable standoff allows a PosiTest ATM50 or ATA50 to pull 10, 14 and 20 mm dollies Ideal for high bond strength finishes such as coatings on metal Includes 20 mm stand-off, 20 mm hole saw and 20 mm aluminum test dollies (20)

50 mm C1583 Accessory Kit - AT50CKIT Ideal for measuring the tensile strength of concrete surfaces and concrete repairs and overlay materials Conforms to ASTM C1583 Includes 50 mm C1583 steel dollies (4), 50 mm diamond grit cutting tool with arbor and 50 mm C1583 stand-off NOTE: Drill required (not included)

Pelican Case for PosiTest AT Pull-Off Adhesion Testers (Order Code: CASEATAB-P) Heavy-duty, waterproof Pelican cases complete with a custom foam insert to securely hold your PosiTest instrument

Complete Kit

The PosiTest AT kits come complete with Automatic Adhesion Tester, built-in rechargeable NiMH battery with charger, dollies, abrasive pad, cutting tool, glue with mixing sticks and palettes, cotton swabs, USB cable, PosiSoft Software, instruction booklet and video, shoulder strap, Certificate of Calibration traceable to NIST, two-year warranty, and a sturdy, lightweight carrying case.

Related Products

ATM Pull-Off Adhesion Tester Positest ATM, ATM20A, ATM50A

AT-VERIFY Adhesion Tester Accuracy Verification Kit

Photo Gallery

Downloads

PosiTest AT-A Automatic Pull Off Adhesion Tester - Instruction Manual

PosiTest AT-A Automatic Pull Off Adhesion Tester -Data Sheet

FAQ's - Frequently Asked Questions

Do your instruments require any formal training for use? Do you offer ‘demo’ models?
No. Our instruments are designed for simple operation, feature easy-to-use menus, both full and quick instruction manuals, and helpful videos. In lieu of demonstration models, we provide unlimited technical support via telephone and/or email, and a limited 30-day money back guarantee.

Is the PosiTest AT calibrated at the factory?
The PosiTest AT arrives fully calibrated and ready to measure. A Long-Form Certificate of Calibration traceable to NIST or PTB is included, which documents actual readings taken by your instrument at our calibration laboratory on standards traceable to a national metrology institute. Beware of ‘Certificates’ or ‘Certificates of Conformance’ offered by competitors. These typically do not include actual instrument readings, and are often insufficient to meet common quality requirements.

Is the PosiTest AT portable, and suitable for use in the field?
Absolutely. With an environmentally-sealed, metal enclosure, heavy-duty hydraulic pump and a high grade industrial pressure sensor, both the Manual and Automatic PosiTest AT are built to last. Weatherproof, dustproof and shockproof, they can be used indoors, outdoors and in all types of weather (meets or exceeds IP 65). For added utility and convenience, PosiTest AT-A Automatic models also include a handy shoulder strap and rubberized grips.

Does the PosiTest AT include steel loading fixtures (dollies)?
The PosiTest AT is supplied with self-aligning dollies that are precision-manufactured from strong and lightweight aluminum alloy (6061-T6). As a lower-cost alternative to steel loading fixtures, factory aluminum dollies are a single-use/consumable item and ideal for keeping as a permanent visual record of testing.

Do you have a recommended adhesive for my particular application?
The ResinLab EP11HT epoxy adhesive supplied with the PosiTest AT is simple to use and suitable for testing a wide range of coating types. In some instances, specialized coatings will require a more specialized adhesive.

Is the PosiTest AT-A more accurate than the PosiTest AT-M?
The certified accuracy of both PosiTest AT models is identical. However, the fully automatic design of the PosiTest AT-A provides improved measurement consistency by eliminating the potential for operator influence from the test process.

What is the difference between the 20mm and the 50mm loading fixtures?
The 50 mm dolly is commonly recommended for use with concrete, wood and composite substrates, and measures coatings with expected adhesion values between 50 psi and 560 psi (50 - 500 psi for AT-M models). The 20 mm dolly is recommended for testing coatings applied to metals or with expected adhesion values greater than 500 psi.

Can I use the PosiTest AT-A on curved surfaces?
Yes. Feedback from our customers is that the PosiTest AT gages are suitable for testing most internal or external pipe applications greater than 200 mm in diameter. In such cases, the maximum glue gap between the surface of the 20 mm dolly and the coating is 0.5 mm. For smaller pipe diameters, depending on the expected pull-off strength of the coating, it may be possible to use a 10 mm or 14 mm dolly. External diameters can be decreased to as low as 50 mm and 100 mm, for the 10 mm and 14 mm dollies, respectively. Manufacturers do do not provide or support the use of curved dollies for adhesion testing. In addition to affecting the surface area used in calculating pull-off strengths and the direction of the force lines (creating unwanted shear forces), most adhesion testing standards specifically call for the use of flat dollies.

How many measurements can I take with the PosiTest AT-A on a single battery charge?
The rechargeable battery pack (user replaceable) in the PosiTest AT-A can perform over 200 tests on a single charge. Use the included AC adaptor to continue testing as the battery recharges.

What is the lowest adhesion strength that the PosiTest AT-A can measure?
When utilized with a 50mm dolly, the PosiTest AT is in a priming state until reaching a priming pressure of 50 psi. It is only after the priming pressure is reached that the instrument begins calculating and displaying the pull rate. While it is possible to obtain readings below this priming pressure with the AT-M model, the AT-A automatic does not allow the operator to build priming pressure very slowly and is therefore not suitable for use below the priming pressure of 50 psi. Note that all reported adhesion values (including those obtained below the priming pressure) are subject to the PosiTest AT gage’s full-scale accuracy of ± 1% (± 30 psi, AT-M; ± 35 psi, AT-A).

Is there a faster curing adhesive than the epoxy supplied with the PosiTest AT?
The versatile epoxy adhesive supplied with the PosiTest AT reaches full cure within 24 – 48 hours. Operators who require faster cure times should evaluate other adhesives for their compatibility with both the coating being tested and our aluminum test dolly. Cyanoacrylate (‘super glue’) type adhesives are often sufficient for lower pull-off strengths.

Can I use the PosiTest AT on flexible or brittle substrates?
The PosiTest AT is designed for use with rigid, structural substrates. A flexible substrate can adversely impact test accuracy and repeatability. Furthermore, use of the PosiTest AT for measuring the adhesion of coatings applied to a brittle substrate typically results in the destruction of the substrate material, making it challenging to quantify the coating-substrate bond strength.

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