PosiTest Pull-Off Adhesion Tester INSTRUCTION MANUAL v. 3.0 PosiTest AT (manual) PosiTest AT-A (automatic) Simple. Durable. Accurate.
Introduction The portable, hand-operated 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 pressure is displayed on a digital LCD and represents the coating's strength of adhesion to the substrate.
Step 1: Dolly & Coating Preparation Dolly Preparation 1. To remove oxidation and contaminants, place the included abrasive pad on a flat surface and rub the base of the dolly across the pad 4-5 times. 2. As required, remove residue left from the abrading process using a dry cloth or paper towel. Coating Preparation 1. Lightly roughen the coating using the included abrasive pad.
3. Gently push down on the dolly to squeeze out excess adhesive. Do not twist or slide the dolly back and forth on the coating as air bubbles may be generated. 4. Carefully remove excess adhesive from around the edges of the dolly with included cotton swabs. 5. Allow to cure per the adhesive manufacturer's instructions NOTE: Many adhesives cure faster and provide a stronger bond when cured with heat. Similarly, cold environments may cause a longer cure time and weaker bond strength.
Step 4a: Pull-Off Test (PosiTest AT Manual) Battery Compartment Pump Handle LCD Actuator Handle Hose Actuator Assembly USB port Pump Quick Coupling The PosiTest AT powers-up and displays dashes when the button is pressed. To preserve battery life, the instrument powers down after 5 minutes of no activity.
3. Close the pressure relief valve on the pump completely. (turn clockwise) NOTE: As required, verify and adjust the dolly size by pressing the button. Select the pressure units by pressing the button. The instrument will maintain these adjustments even after the button is pressed. 4. Zero the instrument BEFORE pumping by pressing the button. This prepares the instrument for the test by clearing the display, and zeroing the instrument. 5.
Step 4b: Pull-Off Test (PosiTest AT-A Automatic) Hose LCD Actuator Handle USB port Actuator Assembly AC Adapter Port (Charges batteries and powers instrument) Quick Coupling Quick Guide (1) Connect the actuator to the dolly (2) Power-up with the button (3) Verify measurement units, dolly size and pull rate (4) Ready the instrument with the button (5) Test with the button 1.
4. Press the button to ready the instrument. This prepares the PosiTest for the test by clearing the display and zeroing the instrument. 5. Press the button again to start the test that consists of 4 stages that occur automatically: Stage 1. Initiation - the display shows a blinking "0". Stage 2. Priming - the pump applies initial pressure to the dolly. Stage 3. Test - when the priming pressure has been achieved (see step 5 on pg.
Step 5: Analysis of Test Results Test results can be considered 100% valid when the coating is completely removed from the substrate. When only a portion of the coating is removed, specific results should be noted including the fracture pattern to determine the cohesive properties of the coating and adhesion properties between the dolly and adhesive, adhesive and coating, distinct coating layers, and coating and substrate.
Power Supply / Low Battery Indicator PosiTest AT (manual) 2AAA atteries aline b As the batteries become weak the symbol will alk appear on the LCD. The batteries should be replaced at the earliest opportunity. Power Source: AAA alkaline batteries USE ONLY AAA ALKALINE BATTERIES. Nickel-cadmium and nickel-metal hydride rechargeable batteries will work but the low battery symbol may stay on.
Calibration The PosiTest is shipped with a Certificate of Calibration showing traceability to a national standard. For organizations with re-certification requirements, the PosiTest may be returned at regular intervals for calibration. DeFelsko recommends that our customers establish the instrument calibration intervals based upon their own experience and work environment.
