What is a high voltage porosimeter?

A high voltage porosimeter is a non-destructive instrument for detecting discontinuities in a coating system, including cavities, pinholes, and cracks. Other names include porosity detector, continuity tester, and cavity tester. There are two types of detectors: low voltage (wet sponge) and high voltage (spark tester). Low voltage detectors, such as the PosiTest LPD, are typically used on coating systems less than 500 µm (20 mils) thick. High voltage spark testers, such as the PosiTest HHD, operate at voltages up to 35,000 V and are typically used on coatings over 500 µm (20 mils) thick.

What is meant by the term "rod-type high voltage porosimeter" or "harness"?

A "rod" type high voltage porosimeter is a self-contained detector with internal battery power and electrodes that attach to the end of an extension rod (rod). It is a compact device. Harness type detectors typically have a separate battery worn on the belt or shoulder strap and electrodes that attach to a handle. The PosiTest HHD is the first combined rod / harness type instrument on the market. With the optional remote handle attachment, the PosiTest HHD converts into a harness style instrument for voltages below 15kV.

How is a high voltage test performed?

A high voltage porosity test is performed by moving a charged electrode over the coated surface. When porosity is encountered, current flows from the electrode into the substrate. Current returns to the detector through the ground wire (earth), completing the circuit and triggering audible and visible alarms. A built-in voltmeter measures and displays output voltages on the screen while in use.

Why is porosity measurement important?

After applying a protective coating, it is important to ensure that there are no defects or discontinuities that expose the substrate underneath. Small areas of thin or missing coating, called “pinholes” or “cavities”, can become hot spots of corrosion and dramatically reduce the life of a protective coating system. They may be invisible to the naked eye. Porosity detectors are often used in applications where corrosion is difficult to control, or in aggressive operating environments where the performance of the protective coating is critical.

How does the PosiTest HHD measure coatings on concrete?

When measuring coating thickness, concrete is not considered a "conductive" substrate because it is much less conductive than metal. However, concrete is still slightly conductive and can carry enough current to allow porosity detectors to work. Therefore, for the purpose of detecting porosities, concrete is considered a "conductive" substrate.

Are custom size electrodes available?

Yes. DeFelsko manufactures a wide variety of coil spring and flat wire brush electrodes. Custom sizes are available upon request.

Are inner tubes, semicircles and other types of electrodes available?

At launch, a flat brush and spring electrodes will be available in pre-stocked and custom lengths, in addition to the portable rubber paddle and fan brush. DeFelsko plans to add more types of electrodes in the future, depending on demand. If you have a request for an electrode configuration not currently offered by DeFelsko, please let us know.

Which electrodes are compatible with the PosiTest HHD?

The PosiTest HHD offers standard connectors and adapters for compatibility with almost all existing electrodes, including SPY, PCWI and Tinker & Rasor.

What is the PosiTest HHD controller?

The PosiTest HHD Controller is a calibrated voltmeter (peak counter, jeep counter) ideal for checking the operating voltage of DC pulsed and continuous cavity detectors in the range of 500 to 35,000 volts. Is the PosiTest HHD controller required to use the PosiTest HHD high voltage high voltage porosimeter? No. The PosiTest HHD has a built-in voltmeter (peak counter, jeep counter) with a traceable long form calibration certificate. However, some standards require a stand-alone voltmeter.

Is the new PosiTest HHD compatible with PosiSoft solutions?

No. The PosiTest HHD does not record any data.

How is the PosiTest HHD calibrated at DeFelsko?

Each PosiTest HHD is calibrated using instruments traceable to a national metrology laboratory. A detailed calibration certificate containing the actual measurement values is included with each instrument.

Are there special shipping considerations for the PosiTest HHD lithium-ion batteries?

The PosiTest HHD and an additional spare battery (charged at less than 30% of its capacity) can be shipped by air and surface transport on major carriers (UPS, FedEx and DHL) to all countries, subject to additional labels. Note: When returning the PosiTest HHD for repair or service, DO NOT include a battery.