Asphalt Institute Vacuum Viscometer, Size 100

Asphalt Institute Vacuum Viscometer, Size 100

The Asphalt Institute Vacuum Viscometer, Size 100, is a precision laboratory instrument engineered for determining the absolute viscosity of highly viscous materials — particularly asphalt binders (bitumen) — at the industry-standard temperature of 140°F (60°C). Widely used in paving and roofing applications, this viscometer plays a critical role in quality control, materials research, and specification compliance, ensuring that asphalt products meet the strict performance requirements of modern infrastructure projects.

How it Works: The viscometer operates on the principle of capillary tube viscometry under a controlled vacuum. A 3mL preheated liquid sample is introduced into the instrument. A regulated vacuum is then applied to draw the liquid through a precisely calibrated capillary tube. The time taken for the leading edge of the liquid to travel between two clearly defined timing marks is recorded in seconds. This elapsed time is multiplied by the instrument's unique calibration factor — provided on the included Certificate of Calibration — to yield the absolute viscosity expressed in poise. This method ensures highly repeatable and accurate results when performed under controlled temperature conditions.

Why Viscosity Testing Matters: Viscosity is a fundamental property of asphalt binders that directly influences pavement performance. Asphalt that is too viscous may be difficult to work with during construction, while asphalt that is insufficiently viscous may lead to rutting or deformation under load. Accurate viscosity measurement ensures that binders are properly graded and suitable for their intended application, whether in highway paving, airport runways, or roofing systems.

Key Specifications — Size 100 (PT-113):

• Viscosity Range: 600–12,800 poise, suitable for many standard grades of paving asphalt
• Testing Temperature: 140°F (60°C)
• Required Sample Volume: 3mL
• Required Bath Depth: Minimum 7in (180mm) for complete and uniform immersion
• Dimensions: 10.25 x 1.625in (260 x 41mm), W x D
• Material: High-quality borosilicate glass for superior durability and thermal resistance

Operation and Required Equipment: To conduct a test, the viscometer must be held in a precise vertical position within a Constant Temperature Viscosity Bath. The Viscometer Neoprene Holder (sold separately) is required to provide stable, properly aligned support during testing. Maintaining the exact 140°F (60°C) test temperature is critical — even minor temperature fluctuations can significantly affect viscosity readings — making a high-precision Constant Temperature Viscosity Bath (also sold separately) an essential component of the testing setup.

Available Models: Asphalt Institute Vacuum Viscometers are available in five sizes to cover a comprehensive range of viscosity requirements:

• (Size 25): 42–800 poise
• (Size 50): 180–3,200 poise
• (Size 100): 600–12,800 poise
• (Size 200): 2,400–52,000 poise
• (Size 400): 9,600–200,000 poise

Selecting the correct size for your application is important. If the viscosity of your sample falls outside the range of your chosen viscometer, results may be inaccurate or the test may not be completable. When in doubt, begin with a mid-range model or consult viscosity data from the asphalt supplier.

Features:

• Constructed from high-quality borosilicate glass for long-lasting durability and resistance to thermal shock
• Precisely measures absolute viscosity of bitumen and other highly viscous liquids
• Clearly graduated timing marks for easy and accurate flow time measurement
• Conforms to industry standards for asphalt binder testing
• Unique calibration constant provided for each individual instrument, ensuring traceability and accuracy

Included Items:

• Asphalt Institute Vacuum Viscometer, Size 100
• Certificate of Calibration, specific to the instrument

Required Accessories (Sold Separately):

• Viscometer Neoprene Holder: Provides stable vertical support within the constant temperature bath
• Constant Temperature Viscosity Bath: Maintains the required 140°F (60°C) test temperature with high precision

Meets the Following Test Standards:

• AASHTO T 202
• ASTM D2171 / D2171M