DeFelsko PosiTest AT-A User manual

Automatic Pull-Off Adhesion Tester
Instruction Manual

1
Introduction
The PosiTest AT-A 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 dis-
played on a digital LCD and represents the coating's strength of
adhesion to the substrate.
n accordance with ASTM D4541, D7234, SO 4624, and
others, the PosiTest AT-A evaluates the adhesion (pull-off
strength) of a coating by determining the greatest tensile pull-off
force that it can bear before detaching. Breaking points,
demonstrated by fractured surfaces, occur along the weakest
plane within the system consisting of the dolly (loading fixture,
stu ), glue, coating layers, and substrate.
Basic teps to Perform a Pull-Off Test
1. Dolly & Coating Preparation
Clean and abrade the dolly and coating (pg. 3)
2. Glue & Dolly Application
Prepare the glue, apply it to the dolly, and place the dolly on the
coated surface, allowing the glue to cure (pg. 4).
3. Test Area Isolation - optional
solate the test area of the coating from the area surrounding
the dolly by cutting or drilling (pg. 5).
4. Pull-Off Test (pg. 5).
5. Analysis of Test Results
Examine and evaluate the dolly and coating to determine the
nature of the coating failure (pg. 8).

2
The PosiTest AT-A powers up when the button is pressed.
To preserve battery life, the instrument powers down after 5
minutes of no activity. Alternatively, press and hold the
button for 5 seconds or select Power Off from the menu.
nstrument functions are menu controlled. To access the Menu,
press the button. Navigate using the multifunction keypad
or touch screen display.
PosiTest AT-A Automatic
USB Port Quick Coupling
Actuator
Assembly
Multifunction Keypad
Directional buttons are used to navigate through
menu options and adjust parameters.
Access Menu / Select
Power On / Start Test / Return to Main View
Stop Test / Power Down (hold for 5 seconds)
Screen Capture: Press both buttons simultaneously to
save an image of the the current display. The last 10 screen
captures are stored in memory and can be accessed when
connected to a computer (see PosiSoft USB Drive pg. 12).
Note: Some menus have more than one view.
Use the or uttons or swipe the touch
display to switch etween views.
Hose Actuator
Handle
Touch Screen Display
AC Adapter Port
(Charges batteries
and powers
instrument)

3
Carousel: indicates the current view. Swipe horizontally
or use arrow keys to switch etween views.
Pull Parameters
(pg. 10)
WiFi Bluetooth U B
(Status icons)
Pull Chart
displays
pressure
over time
Current
Reading
Touch creen Display
Dolly
ize
Pull Rate Limit Hold Time
Use the touch screen to interact with menu options. Swipe
horizontally to navigate between views or vertically to move
between batch readings. Alternatively, the directional buttons can
be used for navigation.
Battery
(pg. 7)
Main View (shown with memory atch open)
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.
As coating abrasion may introduce flaws, it should
only be used when necessary to remove surface contaminants,
or when the bond strength between the glue and the coating
is insufficient for pull testing.
NOTE:

Glue & Dolly Application
Glue election
The glue included in the PosiTest AT-A kit has been selected due
to its versatility. This glue has minimal impact on a variety of
coatings and has a tensile strength exceeding the maximum
performance capabilities of the pressure system under ideal
conditions. Other glues may be preferred based on requirements
such as cure time, coating type, working temperature and pull-off
strength. Quick curing one-part cyanoacrylates (super glues) may
be sufficient for painted surfaces, but two-part epoxies are
preferred for porous or rough coatings.
2. To promote the bond between the dolly and the coating,
degrease the area of the coating to be tested using alcohol or
acetone to remove any oil, moisture or dust.
Ensure that any alternative abrasion techniques,
degreasers or adhesives do not alter the properties of the coating.
Test by applying a small amount of degreaser or glue to a sample
area and observing effects.
NOTE:
Dolly Application
1. Mix the glue per manufacturer’s instructions and apply a
uniform film of glue on the base of the dolly.
2. Attach the dolly to the prepared coating test area.
f the coated surface to be tested is overhead or vertical,
a means to hold the dolly in place during the cure time may be
required, i.e. removable tape.
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:
4

Test Area Isolation
The decision of when to cut around a dolly is dependent on the
standard, specification, or contractual agreement to which the test
is to comply. The primary purpose for cutting through the coating is
to isolate a specific diameter test area. When the decision to cut
into the coating has been made, it is recommended to cut all the
way through to the substrate. As a minimum, it is suggested to
carefully cut away excess glue from the dolly application process.
This typically prevents a larger area of coating from being pulled
away from the substrate, resulting in a higher pull-off pressure.
Cutting Instructions
1. Cut through the coating around the edges of the dolly with
the included cutting tool, removing any excess glue.
2. Clear away any debris from the cutting process.
NOTES:
- Cutting may induce coating surface flaws such as
microcracking that may alter test results.
- For coatings with strong lateral bonding, it is recommended to
cut completely through the coating down to the substrate.
Drilling Template
When testing very thick coatings, the optional drilling template
may be preferred.
1. Push the actuator handle completely down into the actuator
assembly. Place the actuator over the dolly head and
attach the quick coupling to the dolly by reaching through the
holes in the actuator and lifting the coupling. Release the
quick coupling when the dolly head is completely engaged.
2. Press the button to power-up the instrument if necessary.
3. Verify Pull Parameters (pg. 10) are set to the preferred dolly
size, pull rate, pull limit and hold time. Change if necessary.
Pull-off Test
Prepare the Instrument
The 50 x 50 mm square dolly size is used for testing tile
adhesion and should NOT be used when testing with 50mm
round dollies.
NOTE:
5

f recording of test results is desired, a memory batch
must be opened prior to the test. Select New Batch from the
Memory menu (pg. 9).
NOTE:
4. Press the button to initiate the test.
nThe instrument begins building pressure (priming stage) and a
green animated arrow (up) appears on the display. When the
priming pressure is achieved the LCD starts displaying pressure
versus time on the chart.
nPressure build-up stops when the dolly is pulled from the
surface, the pull limit has been reached or when the button is
pressed. The maximum pressure value will blink on the display
and a red animated arrow (down) will display while the pump
retracts the actuator.
Perform the Test
CAUTION: To avoid injury, keep fingers a ay from the
quick coupling and actuator assembly until the pull test
has completed and the actuator has been fully retracted. Press the
stop button to abort the pull test at any time.
Setting a Pull Limit or stopping the test before a fracture
occurs is useful when the coating strength exceeds specified
requirements.
NOTE:
5. Remove the dolly from the actuator assembly.
6. Examine the dolly and surface to analyze the result (pg. 8).
Recording the Result
f a memory batch is open, the maximum pressure result is
automatically stored into memory (pg. 9). Pass/fail, pull
parameters, date and time are also recorded.
The nature of the fracture (cohesive, adhesive, glue), batch and
reading notes can also be recorded. Swipe the touch screen
horizontally or use the left/right buttons to navigate to the
appropriate view and select Edit. See Memory Views (pg. 7).
6

Memory Views (carousel)
Main View Reading ummary
Reading NoteLayer/Fracture Batch Note
When a memory batch (pg. 9) is open, a carousel appears at the
top of the display. Views are represented by dots, the solid dot
indicates the current view.
Swipe horizontally to navigate between views or vertically to move
between batch readings. Alternatively, the directional buttons can
be used for navigation. Six views are available:
Reading List
All stored measurement data can be accessed using PosiSoft
solutions (pg. 12).
Recording Fracture Analysis
Layer 2
Layer 1 Layer 2: 50% Cohesive (C)
Layer 1: 50% Cohesive (B)
The cohesive and adhesive fracture visual analysis results can
be recorded (available for up to 5 coating layers).
7
Dolly
Face
Coated
urface

Cohesive and adhesive fractures are identified as follows:
Select Edit to set the number of layers
and cohesive/adhesive fracture details.
Use the buttons to adjust.
Analysis of Test Results
Upon completion of the pull-off test, the dolly and coated surface
should be examined. n addition to pull-off force, many National
and nternational standards such as ASTM D4541 and SO 4624
require the nature of the fracture to be recorded.
Dolly Face Coated urface
Adhesive fracture:
fracture occurs at the interface
between layers (coating on
dolly face differs from surface).
Cohesive fracture:
fracture occurs within a coating
layer (same coating on dolly
face and coated surface).
n
n
8

Glue failures typically occur when the glue is improperly mixed or
the coated surface has not been adequately prepared (pg. 4).
The PosiTest AT-A provides an interface to document the nature
of the fracture for each pull-off test (pg. 7). Fracture results are
included in test reports.
Glue failure: visible separation of the glue from itself,
the coating, or dolly (no coating visible on the dolly face).
Dolly
Glue
Cohesive fracture
(within a layer)
Adhesive fracture
(between layers)
Glue failure
(coating/glue)
UB TRATE
n
Memory Menu
New Batch
Open
Closes any currently opened batch and creates a new memory
batch, named using the lowest available number (example: B2).
New batches are date stamped when they are created.
The PosiTest AT-A stores 100,000 readings in up to 1,000
batches. Stored measurements can be reviewed on-screen or
accessed via computers, tablets, and smart phones.
Selects a previously created batch to open and make current.
9

10
Close
Stops the recording process, closes the current batch, and
removes batch information from the display.
etup Menu
Pull Parameters
Dolly ize: Select the dolly size being utilized for the test (10,
14, 20, 50, or 50 x 50 mm)
Rate: User selectable pull rate (unit/sec). Specified rate is
maintained for the duration of the test.
Limit: Pressure will build-up until the set Limit is reached or the
dolly is pulled from the surface, whichever occurs first. By default,
the instrument will pull to the maximum limit for selected dolly size
(see Technical Data pg.16).
Select desired parameter using the buttons or touch
screen. Use the and buttons to adjust.
Delete
Removes a batch and associated measurements from memory.
Hold Time:
(up to 60 seconds)
pressure is
maintained (held)
at defined Limit.
Default: 0 seconds
Hold Time is
displayed on
the pull chart
(shaded area)
Defined
Hold Time
Orientation
Rotates display between landscape (default) or portrait views.
deal for use in horizontal or vertical positions.

Units
Converts the display from psi, MPa, N/mm2, or Newtons (unit of
force). Existing measurements in memory are not converted.
Switching units closes Memory.
Gage Info
Displays the model number and serial number, PosiSoft.net
registration key, the amount of remaining memory for storage of
readings, date and time, and software packages.
For security purposes, the registration key is required to add the
Gage to your PosiSoft.net account (pg. 12).
Restores factory settings and returns the instrument to a known
condition. The following occurs:
- All batches, stored readings, notes, batch names, and screen
captures are erased.
- Menu settings are returned to the following:
Memory = OFF
Pull Parameters = default
Orientation = Landscape
Bluetooth = ON
WiFi = OFF
U B Drive = ON
Units = psi
Backlight = Sun
Language = English
Reset
Date, Time, and WiFi are not affected by a Reset.
NOTE:
n the unlikely event that the instrument becomes unresponsive
or will not power down, press and hold and until the
screen fades to white, then release. The gage will restart.
All measurements are date and time stamped (24 hour format)
when stored into memory. t is therefore important to keep both
the date and time current using this menu option. Use the
and buttons to scroll, and the and buttons to adjust
each value. The instrument’s date and time can also be viewed
in Gage nfo and on top of the main menu.
et Clock
11

Selects display brightness (Sun, Normal, or Night). f Auto Dim is
enabled (default), the display dims slightly after a period of no
activity to conserve battery life. Press the button to brighten
the display.
Backlight
Accessing tored Measurement Data
DeFelsko offers the following free solutions for viewing, analyzing
and reporting data:
Posi oft U B Drive - Connect the instrument to a PC/Mac using
the supplied USB cable. View and print readings and graphs
using universal PC/Mac web browsers or file explorers. No
software or internet connection required.
Posi oft Desktop - Powerful desktop software (PC/Mac) for
downloading, viewing, printing, and storing measurement data.
ncludes a customizable, templated PDF Report Generator. No
internet connection required.
Posi oft.net - Web-based application offering secure, centralized
storage of measurement data. Access your data from any web-
connected device.
PosiTector App - App for compatible iOS and Android smart
devices. Permits users to create, save and share professional
PDF reports. Add images and notes using the smart device’s
camera and keyboard.
For more information on our PosiSoft solutions, see:
www.defelsko.com/posisoft
Connect Menu
Allows connection to your local wireless network or mobile
hot spot. deal for using your network’s internet connection for
synchronizing stored measurements with Posi oft.net (above).
See www.defelsko.com/wifi
WiFi
12

13
When U B Drive is enabled , the PosiTest AT-A uses a USB
mass storage device class which provides users with a simple
interface to retrieve stored data in a manner similar to USB flash
drives and digital cameras. U B Drive is also required to import
stored measurements into Posi oft Desktop software (pg. 12).
U B
When enabled and connected to a computer, the PosiTest AT-A
will be recognized as a Key oard. Readings are sent to the
computer as they are taken, emulating keystrokes, followed by a
carriage return.
Keyboard
tream
NOTE:
Stream individual readings to a USB connected computer via a
serial protocol. deal for use with serial compatible SPC data
collection software.
For more information on USB Keyboard and Streaming
visit: www.defelsko.com/usb/stream
The above WiFi and U B menus contain a ync .net Now
option. When selected, the instrument immediately synchronizes
stored measurement data via its respective communication
method (internet connection required). Alternatively, select Auto
ync .net from within the U B connect menu to automatically
synchronize upon connection to a PC. Additional measurements
added to memory while connected are synchronized only when
the USB cable is disconnected and reconnected, or when the
ync.net Now option is selected. WiFi connected gages
automatically attempt synchronization upon power-up.
ync .net Now
Posi oft Desktop is required when using U B to
synchronize measurements with PosiSoft.net.
NOTE:
Allows communication with a smart device running the
PosiTector App (pg. 12) via auto-pairing Bluetooth mart
(BLE) wireless technology.
Bluetooth mart

ync Batches
Select batches to flag them for synchronization to the PosiTector
App. ync Batches is useful when connecting a new device to
an instrument with pre-existing batches, since only batches
created while Bluetooth mart is enabled are automatically
selected.
Selected batches are synchronized when the next reading is
taken in a batch flagged for synchronization, or when the ync
Batches option is selected at the bottom of the list of selected
f Bluetooth mart is disabled or disconnected, data
from batches selected in the ync Batches menu are held in a
queue until communication with the PosiTector App is re-
established.
NOTE:
end Batches
Transfers selected batches to the PosiTector App. end Batches
is useful when switching between devices, as only readings and
batches that have yet to be synchronized with any smart device
are synchronized automatically.
The end Batches option is visible in the menu when the
instrument is connected to a smart device running the PosiTector
App.
The instrument will perform a Hard Reset (pg. 11)
after an update. All stored measurements will be erased from
memory.
Updates
Determine if a software update is available for your instrument.
See www.defelsko.com/update
WARN NG:
14

15
Power upply / Charging
Power ource: Built-in rechargeable NiMH battery
>200 pulls with full charge
The built-in rechargeable NiMH batteries are charged using the
included AC power supply/charger. Ensure batteries are charged
prior to use. The USB port will not charge or power the PosiTest
AT-A.
The charging process takes 2-3 hours depending on remaining
battery power. Alternatively, the AC power supply can be used to
power the instrument.
The icon will display while the instrument is charging.
When fully charged the icon will appear.
To maintain battery performance, it is recommended to fully
charge the PosiTest AT-A gage every month. Avoid completely
discharging the battery.
The PosiTest AT-A internal NiMH battery pack is user
replaceable. n the unlikely event power issues are experienced,
please contact our technical support or your local dealer for OEM
battery pricing, availability and detailed replacement instructions.
NOTE:
Calibrations are typically performed by the instrument
manufacturer or by a certified calibration laboratory in a controlled
environment using a documented process. The PosiTest AT-A is
shipped with a Certificate of Calibration showing traceability to a
national standard. For organizations with re-certification
requirements, the PosiTest AT-A may be returned at regular
intervals for calibration. DeFelsko recommends that our customers
establish their instrument calibration intervals based upon their
own experience and work environment. Based on our product
knowledge, data, and customer feedback, a one year calibration
interval from either the date of calibration, date of purchase, or
date of receipt is a typical starting point.
Calibration and Verification
Calibration

Technical Data
Conforms to: ASTM D4541, ASTM D7234, SO 4624 and others.
pecifications:
*requires the use of a 50 mm stand off
Resolution: 1 psi (0.01 MPa) Accuracy: ±1% Full Scale
The instrument also measures in N/mm2and Newtons (unit of
force). See Units (pg. 11).
Dolly ize (mm) Max Pull-Off
Pressure (AT-A)
10 mm 14,000 psi (96 MPa)
14 mm 7,000 psi (50 MPa)
20 mm 3,500 psi (24 MPa)
50 mm* 560 psi (3.8 MPa)
16
Verification
The PosiTest AT Verifier is available for verifying the accuracy
and operation of PosiTest Adhesion Testers and is an important
component in fulfilling both SO and in-house quality control
requirements. Fully portable with hardshell carry case for use in
the field or laboratory. Learn more at: www.defelsko.com/at/verifier

www.defelsko.com
© 2021 DeFelsko Corporation USA
All Rights Reserved
This manual is copyrighted with all rights reserved and may not be reproduced or transmitted, in
whole or part, by any means, without written permission from DeFelsko Corporation.
DeFelsko, PosiTector, PosiTest, and PosiSoft are trademarks of DeFelsko Corporation registered
in the U.S. and in other countries. Other brand or product names are trademarks or registered
trademarks of their respective holders.
Every effort has been made to ensure that the information in this manual is accurate. DeFelsko
is not responsible for printing or clerical errors.
Limited Warranty, ole Remedy
and Limited Liability
DeFelsko's sole warranty, remedy, and liability are the express
limited warranty, remedy, and limited liability that are set forth on
its website: www.defelsko.com/terms
Returning for ervice
There are no user serviceable components. Any service must be
performed by DeFelsko Corporation.
f you need to return the instrument for service, please follow the
instructions provided at www.defelsko.com/service.

Manual de Instrucciones
Automatic Pull-Off Adhesion Tester

1
Introducción
El medidor de adherencia manual portátil por tracción
PosiTest AT-A mide la fuerza necesaria para realizar una
tracción de prueba sobre un diámetro específico para separar
un revestimiento de su sustrato con presión hidráulica. a
presión se muestra en una pantalla CD digital y representa la
fuerza de adhesión del revestimiento a su sustrato.
De acuerdo con las normas ASTM D4541, D7234, ISO 4624 y
otras, el PosiTest AT-A evalúa la adhesión (fuerza de tracción)
de un revestimiento determinando la mayor fuerza de tensión
por tracción que puede soportar antes de separarse. os puntos
de fractura que se muestran en las superficies se suceden a lo
largo del plano más débil del sistema formado por la dolly, las
capas de revestimiento y el sustrato.
Pasos básicos para probar la adherencia del
revestimiento con un medidor de adherencia de PosiTest:
1. Preparación del dolly y del recubrimiento
a dolly y el revestimiento estarán limpios y lijados (pág. 3).
2. Aplicación del adhesivo y del dolly
Prepare el adhesivo y aplíquelo al dolly. Pegue el dolly
a superficie preprada y deje que el pegamento fragüe (pág. 4).
3. Prueba de desprendimiento de la zona - paso opciona
Separe el revestimiento del área de prueba del resto
del recubrimiento cortando alrededor del dolly (pág. 5).
4. Cómo medir (pág. 5).
5. Análisis de los resultados
Examine el dolly, el revestimiento y evalúelos para determinar
el fallo (pág. 9).