The Elcometer 260 UV Pinhole Flashlight is battery powered and housed in a rugged aluminium case providing a quick, low cost method of testing coatings for pinholes. Featuring a three-Watt purple light emitting diode, the Elcometer 260 UV flashlight has a beam wavelength of 405nm (±5nm), which the human eye perceives as a purple light.
Designed with a specialised diffuser lens that emits a smooth beam image (with no streaks, hot spots or dark spots) and used with National Surface Treatment Centre approved safety glasses for improved contrast, the Elcometer 260UV Flashlight provides optimum integrity and reliability of the visual inspection.
The Elcometer 260 UV Flashlight can detect pinholes from both the base & top coats. A UV reflective additive is applied to the base coat. When inspecting the fluorescent base coat look for black spots or grey areas that indicate pinholes. When inspecting the non-fluorescent top coat, look for glowing spots that indicate pinholes in the top coat (shining thru’ from the base coat).
Features of the Elcometer 260 UV Pinhole Flashlight
Low cost and easy to use • Use UV reflecting base coat and shine the purple light onto the surface. • Any fluorescence identifies pinholes.
Rugged • Manufactured from aluminium alloy and Oring sealed to protect it from moisture and dust.
Portable and secure • Battery powered and features a click-on/push off button with lockout tailcap to prevent accidental activation during transport or storage.
The Elcometer 260 UV Pinhole Flashlight can be used in accordance with:
Corrosion is caused by a steel substrate and oxygen, while contaminants such as water can accelerate the process.
The coating is there to protect the steel from oxygen and contaminants. A flaw in the coating can leave the substrate poorly protected, or in some cases completely exposed.
These flaws are referred to as Holidays, Discontinuities, or Pinholes within the coatings industry; and are often very small or invisible to the naked eye – which is where flaw detectors come in.
Contents 0:31 – What causes corrosion? 0:50 – Types of coating flaws 2:26 – Low Voltage Pinhole or Wet Sponge Technique 3:38 – High Voltage or Holiday Detection Method 5:03 – Continuous DC and Pulsed DC 7:14 – UV Pinhole Technique
There are, essentially, three flaw detection methods…
1. The Low Voltage Pinhole, or Wet Sponge Technique such as the Elcometer 270, is for testing insulating coatings less than 500μm (20mils) thick on conductive substrates, and is ideal for powder coatings and other applications where you do not wish to damage the coating.
The wet sponge method for detecting pinholes – which is a little bit of a misnomer, as the sponge should be damp, and not wet – also works through capillary action.
When you pass a damp sponge steadily over the coated surface, the water is drawn through the holes by capillary action, and when it touches the bare substrate it completes a low voltage circuit, as the test unit is grounded to an uncoated section of the substrate being examined.
When the circuit is complete, the unit alarms, letting you know where you have a pinhole.
2. The High Voltage or Holiday Detection method is where a high voltage current is applied to a probe, which is passed over the coated surface.
The voltage should be high enough so that in areas where the coating is electrically weaker due to a flaw, there is sufficient voltage to break down the gap between the probe and the substrate.
When this break down occurs, the current flows through the substrate, and back into the unit via a grounding cable, setting off an alarm to signal a flaw has been detected.
This allows you to detect flaws that don’t go all the way down to the substrate, as well as voids within the coating.
The high voltage method comes in 2 versions – Continuous DC and Pulsed DC.
Continuous DC is where the current to the probe is constant, and is used to test insulation coatings on conductive substrates up to 7.5mm (300mils) thick.
Elcometer has the Elcometer 266, where the power supply is generated within the handle, and connected back to the instrument via a low voltage cable.
Pulsed DC, on the other hand, is where the energy is contained in very short pulses, with each pulse having more energy than an equivalent Continuous DC instrument.
The break in energy stops the probe from building up a charge on the surface, allowing you to safely test for flaws on damp, dirty, or slightly conductive coatings.
3. The UV Pinhole technique – such as the Elcometer 260, which makes use of a fluorescent coating, which is applied to the surface as a base coat. Once the second coat is applied, any pinholes fluoresce when you shine a UV light on them, revealing their location.
