Asphalt Institute Vacuum Viscometer, Size 200

Asphalt Institute Vacuum Viscometer, Size 200

The Asphalt Institute Vacuum Viscometer, Size 200, is a precision laboratory instrument engineered for determining the absolute viscosity of highly viscous materials, particularly asphalt binders (bitumen), at the standard test temperature of 140°F (60°C). Widely used in quality control and specification compliance across the paving and roofing industries, this viscometer ensures that asphalt materials consistently meet required performance standards and regulatory requirements.

How it Works: Operates on a vacuum capillary principle, a highly reliable method for measuring the flow resistance of viscous materials. A 3mL sample of the asphalt or bituminous material is carefully introduced into the viscometer. The instrument is then submerged in a constant temperature bath, precisely set to 140°F (60°C), and allowed to reach full thermal equilibrium before testing begins. Once equilibrium is achieved, a controlled vacuum is applied to the system, drawing the asphalt upward through a precisely calibrated capillary tube. The elapsed time for the leading edge of the material to travel between two clearly marked timing lines is recorded in seconds. This time measurement is then multiplied by the viscometer's unique calibration factor — provided on the included Certificate of Calibration — to calculate the absolute viscosity expressed in poise (P).

Viscosity Range and Model Selection: The Size 200 model is specifically engineered for a viscosity range of 2,400 to 52,000 poise, making it ideally suited for testing standard paving-grade asphalts that fall within this range. Selecting the correct viscometer size is critical: if the sample's viscosity falls outside the instrument's calibrated range, results may be inaccurate or the test may not be completable. The Asphalt Institute offers a complete family of five viscometer sizes to accommodate a broad spectrum of material viscosities, from softer, lower-viscosity asphalts to heavily polymer-modified or harder binders. Laboratory technicians should consult viscosity data or conduct preliminary testing to select the most appropriate size for their specific material.

Required Equipment for Operation: To conduct a valid and accurate test, the following equipment is necessary:

Constant Temperature Bath: A temperature-controlled bath with a minimum liquid depth of 7 inches (180mm) is required to fully submerge the viscometer and maintain the precise test temperature throughout the duration of the test. Temperature stability is critical to obtaining repeatable and accurate viscosity measurements.

Viscometer Neoprene Holder: The viscometer must be held securely in a perfectly upright, vertical position within the bath during testing. The Neoprene Holder is designed specifically for this purpose, providing a stable and secure grip while protecting the glass instrument from contact with hard surfaces. This accessory is sold separately.

Vacuum Source: A regulated vacuum supply is required to draw the asphalt sample through the capillary tube at a controlled rate.

Timing Device: A stopwatch or automated timing system capable of measuring elapsed time in seconds is needed to record the flow time accurately.

Standards Compliance: The Vacuum Viscometer is manufactured in strict accordance with the specifications outlined in the following industry standards:

AASHTO T 202 – Standard Method of Test for Viscosity of Asphalts by Vacuum Capillary Viscometer

ASTM D2171/D2171M – Standard Test Method for Viscosity of Asphalts by Vacuum Capillary Viscometer

Compliance with these standards ensures that test results are accurate, reproducible, and accepted by transportation agencies, material suppliers, and regulatory bodies worldwide.

Key Features:

• Accurately measures the absolute viscosity of asphalt binders and other highly viscous materials in poise (P).
• Designed and calibrated for use at the standard industry test temperature of 140°F (60°C).
• Constructed from high-quality, stress-relieved borosilicate glass for superior chemical resistance, thermal stability, and long service life.
• Precisely graduated capillary tube with clearly defined timing marks for accurate and repeatable flow time measurements.
• Each viscometer is individually calibrated and supplied with a unique calibration constant for traceable, reliable results.
• Compatible with the full range of Asphalt Institute viscometer accessories and constant temperature bath systems.

Included Items:

• Asphalt Institute Vacuum Viscometer, Size 200 (PT-114)
• Certificate of Calibration with the instrument's unique viscometer calibration constant

Required Accessories (Sold Separately):

Viscometer Neoprene Holder: Ensures stable, upright positioning of the viscometer within the temperature bath during testing.

Constant Temperature Viscosity Bath: Maintains the required 140°F (60°C) test temperature with the necessary 7-inch (180mm) minimum liquid depth for full viscometer submersion.

Specifications:

• Size: 200
• Viscosity Range: 2,400–52,000 poise
• Test Temperature: 140°F (60°C)
• Sample Volume: 3mL
• Capillary Material: Borosilicate glass
• Standards Compliance: AASHTO T 202, ASTM D2171/D2171M
• Product Dimensions (W x D x H): 12 x 2 x 2 in (305 x 51 x 51 mm)