ASTM D2717 Standard Test Method for Thermal Conductivity of Liquids
1. Scope
1.1 This test method covers the determination ofthe thermal conductivity of nonmetallic liquids. It is applicable to liquids that are: (1) chemically compatible with borosilicate glass and platinum; (2) moderately transparent or absorbent to infrared radiation; and (3) have a vapor pressure less than 200 torr at the temperature of test.
1.1.1 Materials that have vapor pressures of up to 345 kPa (50 psia), absolute can be tested provided that adequate measures are taken to repress volatilization of the sample by pressurizing the thermal conductivity cell. The usual safety precautions for pressure vessels shall be followed under these circumstances.
1.2 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
2. Referenced Documents
2.1 ASTM Standards:
D86 Test Method for Distillation of Petroleum Products at Atmospheric Pressure
D1160 Test Method for Distillation ofPetroleum Products at Reduced Pressure
D2887 Test Method for Boiling Range Distribution of Petroleum Fractions by Gas Chromatography
D2893 Test Methods for Oxidation Characteristics of Extreme-Pressure Lubrication Oils
3. Terminology
3.1 Units:
3.1.1 The energy units used in this test method are defined as follows:
1 Cal (International Table calorie) = 4.1868 absolute J
1 Btu (British thermal unit) = 1055.07 absolute J
3.1.2 The units of thermal conductivity commonly used and their interconversion factors are shown in Table 1.
3.2 For working purposes in this test method, the rounded-off value of 4.19 J/cal is used, as this is adequate for the precision of the test and also represents the rounded-off value of watt-second per calorie units in Table 1, thus avoiding the difficulty caused by the dual definition of the calorie.
3.3 Symbols:
Tf = filament temperature, °C,
Tb = bath thermostat temperature, °C,
ΔT = Tf - Tb, °C,
rf = filament radius, cm,
ri = internal radius of tube, cm,
ro = external radius of tube, cm,
L = effective length of tube, cm,
R = resistance of filament, Ω,
I = electric current through filament, A,
KL = thermal conductivity of liquid, cal/s·cm·°C,
KG = thermal conductivity of glass-tube, cal/s·cm·°C,
A = [ln(ri/rf)]/2πL, cm(-1), and
B = [ln(ro/ri)]/2πL KG, s·°C/cal.
