Applicable Standards

This instrument is designed and manufactured in accordance with the national standard GB/T 3536–2008 “Methods for Determination of Flash and Fire Points of Petroleum Products” (Cleveland Open Cup Method).

This instrument is also suitable for the JTG 3410-2025 Highway Code T0611-2011 “Asphalt Flash and Fire Point Test” (Cleveland Open Cup Method), as well as the international standard ISO 2592 test method and the American Society for Testing and Materials standard ASTM D 92.

Uses and Scope of Application

This instrument is suitable for determining the flash point and fire point of viscous petroleum asphalt, coal tar asphalt, and liquid petroleum asphalt materials with a flash point above 79°C using the Cleveland Open Cup (COC) method, for assessing construction safety.

Operating conditions of the instrument

1. Power Supply: 220V ±10%, 50Hz

2. Ambient temperature: -10°C to 50°C

3. Relative humidity: ≤85%

Main Features and Technical Parameters

1. Automatic sweep-and-ignite;

2. The electric furnace heating power is continuously adjustable from 0 to 1000W:

3. The heating wire is protected by a transparent quartz tube, eliminating open flames, offering explosion protection, and enabling rapid heating.

4. Temperature measurement range: 0–360°C.

Main Structure and Principle Block Diagram

Figure 1: Schematic Diagram of the Structure

Figure 2: Schematic Diagram of the Principle

Installation and Usage

1. Open the packaging box and inspect the instrument’s exterior and associated accessories according to the complete set of instruments and technical documentation. If there is no damage or missing parts, proceed with installation according to the structural diagram.

2. Check whether the power ground connection is secure.

3. Turn on the power switch; once the indicator light illuminates, you can begin conducting the test.

4. Wash the sample cup with solvent, dry it, and mount it on the stand.

5. Install the thermometer by inserting it vertically into the sample cup, ensuring that the bulb of the thermometer is approximately 6.5 mm above the bottom of the cup and positioned about 16 mm from the cup’s edge on the side opposite the igniter.

6. After preparing the specimen, pour it into the test cup up to the marked line, ensuring that no other parts of the test cup are contaminated with asphalt. (Note: The specimen heating temperature must not exceed 55°C below the flash point.)

7. All equipment should be placed in a dimly lit indoor area with no significant air circulation, and enclosed on three sides by a windbreak (to be provided by the user).

8. Connect the igniter to a combustible gas pressure vessel (such as a liquefied propane tank or natural gas tank) using a flexible hose. Turn the igniter to one side, perform an ignition test, and adjust the flame so that it forms a standard spherical shape or a small spherical test flame with a diameter of 4 mm ± 0.8 mm.

Test Procedure

1. Begin the heating test, rapidly increasing the temperature at a rate of 14°C/min to 17°C/min. When the sample temperature reaches 56°C below the expected flash point, adjust the heater to reduce the heating rate so that, 28°C before the expected flash point, the heating rate can be maintained at 5.5°C/min ± 0.5°C/min.

2. Begin the test when the sample temperature reaches 28°C below the expected flash point. Press the igniter button every 2°C to cause the igniter’s pilot flame to sweep horizontally in an arc with a radius of 150 mm, centered at the rim of the test cup; the time it takes to traverse from one side of the test cup rim to the other should be approximately 1 second. At this point, verify that the igniter’s pilot flame is a fireball with a diameter of 4 mm ± 0.8 mm, positioned 2.5 mm above the rim of the test cup. (Note: Do not breathe directly over the sample cup during the test.)

3. When a brief, fleeting blue flame first appears on the surface of the test sample, immediately read and record the temperature from the thermometer as the flash point of the sample. Be careful not to mistake the bluish-white flame surrounding the test flame for the flash point flame.

4. Continue heating, maintaining a sample heating rate of 5.5°C/min ± 0.5°C/min, and perform the ignition test using the igniter in accordance with the above operational requirements.

5. When the specimen ignites immediately upon contact with the flame and continues to burn for at least 5 seconds, stop heating and record the temperature shown on the thermometer as the specimen’s flash point.

6. At least two parallel tests shall be conducted on the same sample. When the difference between the two measurement results does not exceed the allowable deviation for repeatability testing, which is 8°C, the integer part of their average shall be taken as the test result.

7. Precision or Allowable Difference

The allowable difference for repeatability tests is: flash point ±8℃, ignition point ±8℃.

The allowable difference for reproducibility tests is: flash point 16°C, ignition point 14°C.

8. After the test is completed, clean up thoroughly and be sure to turn off the power.

Notes and Precautions

1. To ensure clear observation of flash fires, the instrument should be placed in a wind‑sheltered location with relatively low lighting whenever possible during experimental testing.

2. The instrument should be placed in a dry, insulated environment free from contaminants and corrosive gases such as acids or alkalis, and kept clean.

3. During testing, the copper cup should be handled with care to prevent the glass tube from breaking and causing an electrical leak.

4. After the power is turned on, rotate the locator knob clockwise; if the current indicator still does not cross zero, simply turn it a bit further to the right.

5. When adjusting the heating rate, be sure to avoid allowing the heating current to exceed 3.8 A for extended periods of time, in order to ensure the long‑term stable operation of the instrument.

Common Faults and Troubleshooting Methods