STANDARD TAR VISCOMETER AZA0952

Description

Principle of Operation – AZA0952

The AZA0952 operates on the efflux time principle, where viscosity is expressed as the time (in seconds) required for a fixed volume of material to flow through a calibrated orifice under gravity at a specified temperature.

Construction and Working Mechanism

• The instrument consists of a chrome-plated copper bath, which acts as a temperature-controlled jacket.

• The bath is heated using electric immersion heating elements and controlled via a dimmer stat or digital temperature controller, allowing precise temperature regulation at standard test points such as:

  • 25 °C

  • 40 °C

  • 55 °C

• A central sleeve houses the test cup, manufactured from brass or stainless steel, fitted with a precision-machined orifice (commonly 4 mm or 10 mm diameter).

• The orifice is closed using a ball valve assembly, ensuring sharp start and stop of flow.

Test Procedure Overview

1. The bituminous sample is pre-heated and thoroughly stirred to ensure homogeneity.

2. The sample is poured into the test cup and placed inside the temperature-controlled bath.

3. The sample is allowed to equilibrate until it reaches the specified test temperature.

4. The ball valve is released, allowing the material to flow into a receiving flask.

5. A stopwatch is used to record the time taken for a specified volume (typically 50 mL) to discharge.

6. The recorded time, in seconds, represents the empirical viscosity of the material.

This method is well established and referenced in BIS practices, IP methods, and pavement engineering specifications, particularly for cut-back bitumen and road oils used in Indian road projects.

Key Features of AZA0952 Standard Tar Viscometer

Durable and Thermally Efficient Bath

• Chrome-plated copper construction ensures:

  • Rapid and uniform heat transfer

  • Corrosion resistance

  • Long service life under laboratory conditions

Precision-Orifice Test Cups

• Accurately machined orifices ensure repeatable flow characteristics.

• Multiple cup sizes allow testing across different viscosity ranges.

Stable Temperature Control

• Electric heating with dimmer stat or digital controller

• Suitable for all standard bitumen viscosity test temperatures

Uniform Temperature Distribution

• Supplied with a stirrer featuring an insulated handle, ensuring consistent bath temperature during testing.

Simple and Reliable Operation

• Minimal operator dependency

• Ideal for routine quality control and compliance testing

Importance in Road Construction and Bitumen Testing

The AZA0952 plays a critical role in road construction and maintenance by supporting:

Binder Suitability Assessment

Determines whether a cut-back bitumen or road oil has the correct fluidity for:

• Prime coats

• Tack coats

• Surface dressing applications

Application Temperature Guidance

Viscosity values help establish correct spraying and handling temperatures, preventing poor coating or excessive runoff.

Quality Assurance & Compliance

Used by contractors, consultants, and government laboratories to:

• Verify incoming material quality

• Ensure consistency between batches

• Meet MoRTH and project specifications

Performance Prediction

Correct viscosity ensures:

• Effective aggregate coating

• Proper penetration into base layers

• Reduced risk of binder drainage

• Improved long-term pavement durability

Maintenance and Best Practices

• Thoroughly clean test cups and orifices after each test using suitable solvents.

• Avoid air entrapment during sample preparation.

• Periodically verify thermometer accuracy.

• Ensure the ball valve operates smoothly for precise flow initiation.

Technical Specifications – AZA0952

Standards and Compliance

The AZA0952 is designed in accordance with:

• Indian BIS practices for empirical viscosity testing

• IP 72 / BS 2000 series

• Widely accepted pavement engineering and MoRTH practices

Supplied Components

• Viscometer bath with heater and temperature control

• 10 mm test cup

• 10 mm ball valve

• Stirrer with insulated handle

Optional Accessories

• AZA0952A – Cup, 10 mm (Spare)

• AZA0952B – Ball Valve, 10 mm (Spare)

• AZA0952C – Cup, 4 mm

• AZA0952D – Ball Valve, 4 mm

• AZA0952E – Thermometer IP 8C (0 °C to 45 °C)

• AZA0952F – Thermometer IP 9C (40 °C to 85 °C)

• AZA0952G – Thermometer IP 10C (76 °C to 122 °C)

Frequently Asked Questions (FAQ)

Q1. What does AZA0952 measure?
It measures the empirical viscosity of cut-back bitumen and road oils by efflux time.

Q2. What materials are suitable?
Fluid bituminous materials such as cut-back bitumen, road oils, and similar tars.

Q3. How is viscosity expressed?
As the time in seconds required for a fixed volume to flow through a calibrated orifice.

Q4. Why is this test important for roads?
Viscosity determines sprayability, penetration, and coating quality, directly affecting pavement performance.

Q5. What accessories are included?
The bath, heater, stirrer, 10 mm cup, and ball valve. Other items are optional.

Q6. What maintenance is required?
Routine cleaning, proper solvent use, and periodic temperature verification.