Asphalt Institute Vacuum Viscometer, Size 400

Asphalt Institute Vacuum Viscometer, Size 400

The Asphalt Institute Vacuum Viscometer (Size 400) is a high-precision laboratory instrument engineered to measure the absolute viscosity of highly viscous materials, including bitumen (asphalt cement), at a standard test temperature of 140°F (60°C). Accurate viscosity measurement is a critical step in asphalt grading, quality control, and ensuring optimal performance in paving, roofing, and other asphalt-related applications.

Principle of Operation: This viscometer utilizes the principle of capillary viscometry under a controlled vacuum. A precise volume of the test sample is drawn through a calibrated capillary tube, and the time required for the liquid to travel between two clearly marked graduation points is carefully recorded. This elapsed time is then multiplied by the instrument's unique calibration constant to yield the absolute viscosity expressed in poise (P). The simplicity and accuracy of this method make it a trusted approach in both research and quality assurance settings.

For reliable and repeatable results, a minimum sample volume of 3mL is required. The viscometer must be fully submerged in a constant-temperature water bath with a minimum depth of 7 inches (180mm) to ensure the sample remains at a stable and uniform test temperature of 60°C throughout the measurement process.

Product Details: The Size 400 model is specifically engineered for materials exhibiting very high viscosity, with a measurement range spanning 9,600 to 200,000 poise. This makes it ideal for testing stiffer, harder-grade asphalts that fall outside the range of smaller viscometer models. The capillary tube features permanent graduations, enabling easy and accurate reading without the need for additional measurement tools. To ensure secure, stable positioning within the water bath during testing, a compatible Viscometer Neoprene Holder is required (sold separately).

The viscometer is constructed from high-quality, stress-relieved borosilicate glass, which offers excellent chemical resistance, thermal stability, and durability — essential properties for repeated use in demanding laboratory environments.

Compliance and Standards: This viscometer is manufactured in strict accordance with the specifications outlined in AASHTO T 202 and ASTM D2171/2171M, two of the most widely recognized industry standards for asphalt viscosity testing. Compliance with these standards ensures that results are reliable, reproducible, and accepted for use in material specifications, quality control programs, and regulatory reporting.

Available Models: The Asphalt Institute Vacuum Viscometer is available in five sizes to accommodate a wide range of viscosity values, all tested at 140°F (60°C):

• (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 is important to ensure accurate measurement. If the viscosity of the sample falls outside the range of the selected viscometer, results may be inaccurate or unusable.

Key Features:

• Accurately measures the absolute viscosity of bitumen and other highly viscous materials
• Fully compliant with AASHTO T 202 and ASTM D2171/2171M testing standards
• Designed for precise testing at a controlled temperature of 140°F (60°C)
• Permanently graduated capillary tube for consistent, easy-to-read results
• Constructed from high-quality, stress-relieved borosilicate glass for durability and chemical resistance
• Available in five sizes to cover a broad spectrum of viscosity ranges

Included Items:

• Asphalt Institute Vacuum Viscometer, Size 400
• Certificate of Calibration

Required Accessories (Sold Separately):

• Viscometer Neoprene Holder: Provides a stable, secure base for the viscometer during water bath testing, preventing movement that could affect results.
• Constant Temperature Viscosity Bath: An essential accessory for maintaining the precise and uniform temperature required by ASTM and AASHTO test standards. Without a properly controlled bath, test accuracy cannot be guaranteed.

Specifications:

• Viscosity Range: 9,600–200,000 poise
• Test Temperature: 140°F (60°C)
• Minimum Sample Volume: 3mL
• Minimum Bath Depth: 7in (180mm)
• Applicable Standards: AASHTO T 202, ASTM D2171/2171M
• Product Dimensions: 12 x 2 x 2in (305 x 51 x 51mm), L x W x H
• Material: Stress-relieved borosilicate glass