Precision Asphalt Testing with Anton Paar’s PNR 12 Penetrometer: Ensuring Quality and Consistency with Automatic Surface Detection

Asphalt forms the foundation of modern road infrastructure, delivering the durability and stability required for highways, streets, and runways. The key binder component of asphalt is bitumen, and the asphalt and bitumen vary in consistency depending on their grade and the ambient temperature. To ensure asphalt performs optimally under diverse environmental conditions, precise testing of bitumen’s consistency is necessary.

Penetration is a fundamental parameter in bitumen classification systems worldwide. A penetrometer provides accurate measurements of bitumen consistency, ensuring effective quality control and reliable performance in road construction projects.

The PNR 12 penetrometer from Anton Paar is a measurement instrument designed to evaluate the resistance of a material against penetration by a test body, both manually and automatically. This consistency is measured in Penetration Units [PU] or 1/10mm, with results expressed as the depth of the test body’s penetration into the sample.

PNR 12 meets a wide range of international standards, including ASTM, EN, ISO, DIN, IP and JIS, ensuring that its test results for bitumen are accurate, reliable, and globally recognized. Officially certified needles are available from Anton Paar, and the instrument features five pre-set programs aligned with standards across various areas, simplifying testing and enhancing ease of use. Additionally, PNR 12 supports up to 15 user-defined programs, allowing for flexibility in conducting customized tests tailored to specific conditions or requirements.

One of the challenges in bitumen testing is accurately positioning the test body on the sample’s surface, especially with shiny bitumen that reflects the needle or when the sample is submerged in water. This process often demands a high level of skill and experience to achieve precise placement.

PNR 12 addresses this challenge with its automatic surface detection feature, powered by a patented force sensor plunger. This technology ensures the needle is always positioned accurately on the surface of the bitumen, even when submerged in water. This feature is ideal for bitumen samples with a penetration unit [PU] of less than 160.

Once the surface is detected and the needle tip is precisely positioned on the surface of the bitumen sample, the plunger automatically inserts the needle into the sample. The penetration results are then displayed on the screen. This automated process guarantees consistent, error-free results, enabling a reliable assessment of bitumen behavior in the medium temperature range - typically at 25 °C. With an optional temperature sensor, the penetrometer also allows for precise temperature-controlled testing.

For user-friendly operation, the PNR 12 penetrometer features a jog wheel for easy navigation of test programs and settings. The instrument displays results in a clear, digital format. Users can set upper and lower limits for penetration depth. If results fall outside the specified range, alarms are triggered to ensure compliance with product specifications.

PNR 12 can store up to 200 test results in its internal memory, making it easy to track asphalt quality over time. These results can be exported to Excel via USB for further analysis, or integrated into a LIMS system for comprehensive reporting.

The PNR 12 penetrometer enables straightforward assessment of the consistency of bitumen and other pasty, creamy and almost-solid samples. Anton Paar offers suitable test kits for various materials, supporting numerous standardized methods. This covers a wide range of applications in the petrochemical, chemical, pharmaceutical, cosmetics, and food industries, allowing for an almost unlimited range of test scenarios.

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