Asphalt Institute Vacuum Viscometer, Size 50

Asphalt Institute Vacuum Viscometer, Size 50

The Asphalt Institute Vacuum Viscometer, Size 50 (PT-112), is a high-precision instrument engineered for determining the absolute viscosity of highly viscous materials, including asphalt binders (bitumen), at 140°F (60°C). Viscosity measurement at this temperature is a cornerstone of asphalt grading, ensuring materials meet the rigorous performance specifications required for paving, roofing, and other bituminous applications. The Size 50 model is factory-calibrated for a viscosity range of 180 to 3,200 poise, making it well-suited for a broad range of standard asphalt binder grades.

How it Works: This capillary-style viscometer operates on the principle of vacuum-induced flow. A controlled vacuum draws a fixed volume of the asphalt sample up through a precisely manufactured fine-bore capillary tube. The time elapsed (in seconds) for the sample to travel between two calibration marks is carefully measured. This elapsed time is then multiplied by the viscometer's unique, unit-specific calibration constant to yield the absolute viscosity in poise (P). The test requires a minimum sample volume of just 3mL, minimizing material waste.

Each viscometer is meticulously manufactured and individually calibrated to meet the rigorous requirements of AASHTO T 202 and ASTM D2171/2171M, the industry-standard test methods for viscosity of asphalts by vacuum capillary viscometer. This ensures consistent, reliable, and repeatable results across all testing environments.

Testing Requirements: For accurate and compliant testing, the viscometer must be fully submerged in a constant-temperature water bath to a minimum depth of 7in (180mm). The bath must be capable of maintaining a stable temperature of exactly 140°F (60°C) throughout the test, as even minor temperature fluctuations can significantly affect viscosity readings. A 2in (51mm) Neoprene Viscometer Holder is required to secure the viscometer in a perfectly vertical position within the bath, ensuring the sample flows correctly through the capillary. Both the Neoprene Holder and a compatible Constant Temperature Viscosity Bath are essential accessories and are available for separate purchase.

Available Models: The Asphalt Institute Vacuum Viscometers are available in five sizes to accommodate a wide spectrum of asphalt binder viscosities, 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

This range of sizes allows laboratories to select the most appropriate viscometer for the specific grade of asphalt being tested, ensuring the measurement falls within the optimal calibrated range for maximum accuracy.

Key Features:

• Accurately measures the absolute viscosity of bitumen and other highly viscous materials in compliance with AASHTO T 202 and ASTM D2171/2171M
• Ideal for quality control, material specification, and research in the asphalt and bitumen industry
• Constructed from high-quality borosilicate glass for excellent chemical resistance, durability, and clear visibility of the sample during testing
• Precisely graduated markings for accurate and repeatable flow time readings
• Each unit is individually calibrated and supplied with its own Certificate of Calibration

Included Items:

• Asphalt Institute Vacuum Viscometer (Size 50, PT-112)
• Certificate of Calibration with the specific viscometer constant for your individual unit

Required Accessories (Sold Separately):

• Viscometer Neoprene Holder (2in/51mm): Provides sturdy, vertical support for the viscometer during testing, ensuring proper alignment within the bath
• Constant Temperature Viscosity Bath: Essential for maintaining the required 140°F (60°C) test temperature with high stability and uniformity

Specifications:

• Size: 50
• Viscosity Range: 180–3,200 poise
• Test Temperature: 140°F (60°C)
• Minimum Sample Volume: 3mL
• Minimum Bath Depth: 7in (180mm)
• Product Dimensions: 10.25 x 1.625in (260 x 41mm), L x D
• Compliant Standards: AASHTO T 202, ASTM D2171/2171M
• Material: Borosilicate glass