AASHTO T 48:2018 Standard Method of Test for Flash Point of Asphalt Binder by Cleveland Open Cup.
4.1.3. Heat Source—Gas burner or electric heater centered under the opening of the heating plate with no local overheating. If using a gas burner, protect the flame from drafts using suitable shields that do not project above the top of the heating plate.
4.1.4. Thermometer Holder—Supplied with the tester; it shall support the thermometer firmly in a vertical position.
4.1.5. Heating Plate Holder—Support to hold the heating plate level and steady.
4.1.6. Ignition Source Applicator—The device for applying the test flame; may be of any suitable design. but the tip shall be 1 .6 to 5.0 mm (0.06 to 0.20 in.) in diameter at the end and the orifice shall have an approximate diameter of 0.8 mm (0.031 in.). The device for applying the test flame shall be so mounted to permit automatic duplication of the sweep of the test flame, the radius of swing being not less than 150mm (6 in.) and the center of the orifice moving in a plane not more than 2.5 mm (0.10 in.) above the cup. A bead having a diameter of 3.8 to 5.4 mm (0.15 to 0.21 in.) shall be mounted in a convenient position on the apparatus so the size of the test flame can be compared to it.
4.2. Thermometer—An ASTM IIC (11 F) thermometer as prescribed in ASTM E 1 with an accuracy of
0.2°C (0.5°F). The thermometer shall be calibrated according to the requirements specified in R 18. This thermometer shall be used to make all temperature measurements required by this method. The thermometric device shall be mounted in the same position as the test thermometer it replaces.
4.2.1 .2. The thermometric device shall 1) have a maximum scale error no greater than that of the test thermometer it replaces, 2) be capable of indicating temperature within 0.1°C (0.2°F), and 3) have the same temperature response.
4.2.1 .3. The thermometric device shall be standardized at the interval specified in R 18. Guidance for performing the standardization is given in ASTM E220 or E644.
4.3. Filling Level Gauge (optional)—A device to aid in the proper adjustment of the sample level in the cup. It may be made of suitable metal with at least one projection, but preferably two, for adjusting the sample level in the test cup to 9 to 10 mm (0.35 to 0.39 in.) below the top edge of the cup. A hole 0.8 mm (0.03 1 in.) in diameter, the center of’ which is located not more than 2.5 mm (0.10 in.) above the bottom edge of the gauge, shall be provided for use in checking the center position of the orifice of the test flame applicator with respect to the rim of the cup. (Figure 4 shows a suitable version.)AASHTO T 48 pdf download.