ASTM D2533 Test Method for Vapor-Liquid Ratio of Spark-Ignition Engine Fuels
6. Apparatus
6.1 V/L Buret, constructed of borosilicate glass according to the dimensions shown in Fig. 1. The short bottom arm is closed with a rubber serum bottle stopper that is alcohol resistant; U.S. Army Medical Corps type.
6.2 Pressure Control Equipment, including the following:
6.2.1 A 250-mL leveling bulb containing dry glycerol or mercury, attached to the V/L buret by rubber tubing as shown in Fig. 2. The top of the leveling bulb must be fitted with an air-drying device. When mercury is used the drying tube must contain mercury vapor absorbent packed between balls of glass wool. This minimizes the escape of mercury vapor.
6.2.2 Means for measuring the difference in liquid level between the V/L buret and the leveling bulb. A millimetre scale for measuring the heights above a level table top is suitable for use with glycerol. A cathetometer or similar optical leveling device must be used with mercury.
6.2.3 Barometer, accurate to 0.5 mm Hg.
6.2.4 A mercury manometer with 1-mm divisions, required only for measurements at pressures appreciably above or below the prevailing atmospheric pressure (see Note 12). The manometer shall be connected with rubber tubing to one arm of a glass T-tube, the other arms of which shall be connected to the top of the glycerol (mercury) leveling bulb and to a stopcock or pinch clamp.
6.3 Water Bath, glass, at least 10.5 in. (266.7 mm) deep, stirred and thermostatically controlled, capable of being adjusted to any temperature between 90°F (3°C) and 180°F (82°C) and maintaining the water temperature within +/-0.2°F (0.1°C) of the desired temperature.
6.4 Thermometers - ASTM Precision Thermometers having a range from 77 to 131°F and 122 to 176°F (25 to 55°C and 50 to 80°C) and conforming to the requirements for Thermometers 64F and 65F (64C and 65C) as prescribed in Specification E 1 or, for the limited ranges they cover, the ASTM Saybolt Viscosity Thermometers having a range from 94 to 108°F, 120 to 134°F, and 134 to 148°F (34 to 42°C, 49 to 57°C, and 57 to 65°C) and conforming to the requirements for Thermometers 18F, 19F, and 20F (18C, 19C, and 20C) as prescribed in Specification E 1.
NOTE 3 - Digital temperature indicating devices with thermocouple, resistance, or thermistor probes are also acceptable if the system accuracy is at least 0.2°F (0.1°).
6.5 Cooling Bath, containing ice and water at 32 to 36°F (0 to 2°C).
6.6 Hypodermic Syringe, 0.5 and 1.0-mL Hamilton syringes with Chaney adaptors, fitted with a No. 20 gage, 2-in. (51-mm) needle.
6.7 Calibration Accessories, including an analytical balance accurate to 1 mg or better, a capillary stopcock, and weighing vials. A calibration stopper3 for the V/L buret stopcock, that is, an extra three-way solid stopcock stopper with an outlet through the end of the stopper, is convenient during calibration.
7. Reagent
7.1 Acetone
NOTE 4 - Warning: Extremely Flammable.
7.2 Chromic Acid
NOTE 5 - Warning: Causes severe burns. A recognized carcinogen. A strong oxidizer. Contact with organic material may cause fire.
7.3 Glycerol, at least 99 % pure (1 % maximum water content). Store in a dry screw-capped bottle to prevent absorption of moisture.
7.4 Mercury
NOTE 6 - Warning: Poison. May be harmful or fatal if inhaled.
