A LOW TEMPERATURE ADIABATIC CALORIMETER FOR CONDENSED SUBSTANCES. THERMODYNAMIC PROPERTIES OF ARGON

Journal Article · Fri Dec 15 04:00:00 EST 1961 · Proc. Phys. Soc. (London)

DOI:https://doi.org/10.1088/0370-1328/78/6/346· OSTI ID:4785977

Flubacher, P; Leadbetter, A J; Morrison, J A

An adiabatic calorimeter was constructed to study properties of condensed substances 2 to 300 deg K. Two resistance thermometers were used, one of platinum for T > 11 deg K, and one of carbon for T < 11 deg K. The carbon thermometer was calibrated on the thermodynamic temperature scale by using the calorimeter vessel as a gas thermometer; subsequent absolute shifts of its resistance on cycling between room temperature and liquid helium temperatures were taken into account by calibrations against the platinum thermometer. Heat capacities of solid and liquid argon were measured between 2 and 86 deg K with accuracies to plus or minus 2% at the lowest temperatures, increasing to plus or minus 0.2% for T > 20 deg K but decreasing to plus or minus 0.5% at the highest temperatures. In conjunction with these measurements, vapor pressures were measured at 66 to 86 deg K. The heat of fusion was 284.5 plus or minus 0.4 cal mole/sup -1/, the triple point temperature 83.810 deg K, and the triple point pressure 516.86 plus or minus 0.02 mm Hg. The impurity in the specimen of argon was 3 parts per million from a study of the melting range. Direct measurement of the heat of vaporization of the liquid indicated 1563.6 plus or minus 4.6 cal mole/sup -1/ at 85.67 deg K, which corresponds to 1555.0 plus or minus 4.6 cal mole/sup -1/ at the normal boiling point. (auth)

• Research Organization: National Research Council, Ottawa
• NSA Number: NSA-16-013818
• OSTI ID: 4785977
• Journal Information: Proc. Phys. Soc. (London), Journal Name: Proc. Phys. Soc. (London) Vol. Vol: 78
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

ADIABATIC PROCESSES
ARGON
CALORIMETERS
CARBON
ELECTRIC CONDUCTIVITY
ERRORS
EVAPORATION
GASES
IMPURITIES
LIQUEFYING
LIQUIDS
LOW TEMPERATURE
MEASURED VALUES
MELTING
MELTING POINTS
PHASE DIAGRAMS
PHYSICS
PLANNING
PLATINUM
PRESSURE
RESISTORS
SOLIDS
SPECIFIC HEAT
STANDARDS
TEMPERATURE
THERMODYNAMICS
THERMOMETERS
VAPORS
VESSELS