PosiTest  Pull-Off Adhesion
Measures adhesion of coatings to metal, wood, concrete and other substrates

The PosiTest Adhesion Tester literature is available online
http://www.defelsko.com/SalesKit/AT/PosiTest-AT-Literature.pdf

Overview: Measures adhesion of coatings to metal, wood, concrete and other rigid substrates Revolutionary self alignment features and pull rate indicator. Conforms to national and international standards including ASTM D4541/D7234, ISO 4624/16276-1, AS/NZS 1580.408.5 and others

Now available in 2 models... Manual or Automatic

 

• Pull Rate Indicator allows operator to easily monitor and adjust the rate of pull in accordance with international test methods
• Easily select dolly sizes, change measurement units or store readings, with the touch of a button
• Conversion charts not required tester automatically calculates pressure based on dolly size
• Inexpensive, single-use dollies eliminate cleaning for re-use and can be kept as a permanent record
• Each kit comes with everything needed for testing

 

• Environmentally sealed enclosure weatherproof, dustproof and shockproof
• Can be used in any position
• Rugged carrying case
• Two year warranty

 

• Every PosiTest Adhesion Tester pressure system is calibrated and certified to 1% accuracy using NIST traceable load cell
• Self aligning aluminum dolly enables accurate
  measurements on smooth or uneven surfaces
• Hi-grade, industrial pressure sensor ensures
  continued accuracy
• Conforms to national and international standards including ASTM D4541/D7234, ISO 4624/16276-1, AS/NZS 1580.408.5 and others

 

• Internal Memory stores maximum pull-off pressure, rate of pull, test duration and dolly size
• Optional PosiSoft software available for downloading
• LCD displays pressure value in psi or MPa
• 10, 14, 20 or 50 mm dollies maximize capability
  and measurement resolution across a wide range of bond strengths

Two Models (now available in Manual or Automatic)

The PosiTest Pull-Off Adhesion Tester measures the force required to pull a specified test diameter of coating away from its substrate using hydraulic pressure.

The PosiTest AT-A automatic features an electronically controlled hydraulic pump which automatically applies smooth and continuous pull-off pressure at a user-specified rate. More Info The PosiTest AT manual features a heavy-duty manual hydraulic pump designed to apply smooth and continuous pull-off pressure with a single stroke. More Info     Includes all features in overview plus... âñ  New electronically controlled hydraulic pump automatically applies smooth and continuous pull-off pressure at a user-specified rate âñ  Test with the simple push of a button. No twisting, pumping or cranking. No valves to close, needles to reset, or scales to adjust âñ  User selectable pull rates ensure compliance with international test methods for a variety of industries including metal, wood and concrete âñ  Built-in rechargeable batteries perform over 200 tests per charge. Continue testing with AC power while batteries recharge. Supplied with universal AC Adapter Rugged, portable instrument comes complete with convenient shoulder strap. Ideal for lab and field use.   Includes all features in overview plus... âñ  Heavy-duty manual hydraulic pump designed to apply smooth and continuous pull-off pressure with a single stroke âñ  Pull Rate Indicator to manually monitor and adjust the rate of pull âñ  Includes 2 AAA alkaline batteries

Rugged Features: With an environmentally sealed, metal enclosure, heavy duty hydraulic pump and a hi-grade industrial pressure sensor, both the Manual and Automatic PosiTest AT are built to last and can be used indoors and outdoors in all types of weather.

 

 

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. Both the PosiTest AT manual and AT-A automatic 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.

Technical Data (AT manual and AT-A automatic)

Conforms to national and international standards including ASTM D4541/D7234,
ISO 4624/16276-1, AS/NZS 1580.408.5 and others

PosiTest AT (manual model kit shown above)

Resolution: 1 psi (0.01 MPa) Accuracy: ± 1% Full Scale Adhesion Strength Dolly Size Max Pull-Off Pressure 10 mm 10000 psi 70 MPa 14 mm 6000 psi 40 MPa 20 mm* 3000 psi 20 MPa 50 mm** 500 psi 3.5 MPa    *supplied with PosiTest AT    **requires 50mm kit Warranty: 2 Years

Both Kits include:   Adhesion tester with digital display 20 mm aluminum test dollies (20) Abrasive pad Cutting tool Adhesive with mixing sticks and palettes Cotton swabs Instruction booklet Certificate of Calibration traceable to NIST Instructional Video Sturdy, lightweight carrying case Two-year warranty Shoulder strap (AT-A only) Weight of Kit (with case) : 12 lbs / 5.5 kg Carrying Case Dimensions: L – 17 in / 43 cm W – 13 in / 33 cm H – 6 in / 15 cm Aluminum Test Dollies Power: AT Manual – 2 AAA batteries AT-A Automatic – Built-in rechargeable NiMH batteries with recharger/AC power supply. (perform over 200 pull tests per charge)

Adhesion Tester Instructional Video Featuring the PosiTest AT manual

View Video (9 minutes)

Q & A

Are there different models of PosiTest Adhesion Tester to choose from?
Yes, there are two models to choose from. The PosiTest AT-A features an automatic hydraulic pump while the PosiTest AT comes with a manual hydraulic pump.

 

What are the differences between the current PosiTest AT Manual and the new PosiTest AT-A Automatic?
The New PosiTest AT-A is an automatic version of the popular PosiTest AT Manual Adhesion Tester. The electronically controlled hydraulic pump automatically applies smooth and continuous pull-off pressure at a user-specified rate.

New features include...

• Test with the simple push of a button. No twisting, pumping or cranking. No valves to close, needles to reset, or scales to adjust
• User-selectable pull rates ensure compliance with international test methods for a variety of industries including metal, wood and concrete
• Built-in rechargeable batteries perform over 200 tests per charge. Continue testing with AC power while batteries recharge. Supplied with universal AC Adapter

Aside from a few functional differences, your customers will find the New PosiTest AT-A Automatic Adhesion Tester comparable to the current PosiTest AT Manual Adhesion Tester in all respects but the pump.

Are they rugged?
Absolutely. With an environmentally sealed, metal enclosure, heavy-duty hydraulic pump and a hi-grade industrial pressure sensor, both the Manual and Automatic PosiTest AT are built to last and can be used indoors and outdoors and in all types of weather.

What are the benefits of the optional PosiSoft software?
All PosiTest Adhesion Testers have memory for storing data on 200 pulls. This includes maximum pull-off pressure, rate of pull, test duration and dolly size. PosiSoft software downloads this information to a PC. A unique “Listen-to- Gage” feature allows for real time graphing of individual pulls for a more detailed analysis of applied pressure over time (Manual model only).

How are the Manual and Automatic PosiTest Adhesion Testers calibrated at DeFelsko?
The Manual and Automatic PosiTest Adhesion Testers are calibrated against known conditions using NIST traceable equipment. A Certificate of Calibration containing actual measurements is included with every tester.

How much time should be allowed for the included Araldite 2011 to cure?

Are curved dollies available for convex surfaces?
We 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.

Feedback from our customers is that most internal or external pipe applications greater than 200 mm in diameter do not require curved dollies for satisfactory results. In such cases the maximum adhesive gap between the surface of the 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. The smaller surface areas of the dollies will allow them to sit flatter on the curved surface. The height of the actuator pulling the dolly becomes the limiting factor within internal diameters. External diameters can be decreased to as low as 50 and 100 mm respectively.

If you have more specific information on the application it may be possible to provide a more definitive response.

Can pull-off adhesion tests be conducted underwater?
The PosiTest can be used for underwater measurement provided only the cable and actuator are placed under the surface. In such cases, the following precautions should be taken.

• The standoff and actuator should be thoroughly dried immediately upon completion of testing.
• Once dried, a generous amount of lubricant should be applied to discourage corrosion (rust).

Note: During measurement, the manual PosiTest AT may require more than one continuous stroke to complete the test. This differs from our recommendation in the instruction manual and operational video.

PosiTest adhesion testers can be specifically manufactured with longer pressure hoses to facilitate underwater measurement.

Where does failure occur?
Tensile adhesion pulls are evaluated in pounds per square inch (psi) or megapascals (MPa), and visually, as follows:

• Adhesion failure - defined as a failure between two distinct paint layers or between the substrate and the first layer of paint.
• Cohesion failure - defined as a failure or break within one coat of paint (the coating breaks within itself).
• Glue failure - coating bond exceeds the glue strength, and may require re-gluing.

PosiTest AT - Adhesion Tester
ATM	PosiTest® AT Manual Pull-Off Adhesion Tester 0 - 3000 PSI / 0 - 20 MPa
ATA	PosiTest® AT Automatic Pull-Off Adhesion Tester 0 - 3000 PSI / 0 - 20 MPa
AT50KIT	PosiTest® AT Includes 50 mm stand-off, holesaw and test dollies (12) 0 - 500 psi / 0 - 3.5 MPa
DOLLY20	PosiTest® AT Additional 20 mm dollies (10)
DOLLY50	PosiTest® AT Additional 50 mm dollies (4)
ATADHESIVEKIT	PosiTest® AT Adhesive Kit (additional adhesive, mixing sticks, palettes, cotton swabs)
POSISOFTAT	PosiTest® AT PosiSoft Software
TMPLTAS	PosiTest® AT Drilling Template for 50 mm Dollies