TEMPERATURE AND PRESSURE MEASUREMENTS
Thermodynamics
TEMPERATURE AND PRESSURE MEASUREMENTS
Several types of temperature and pressure measurements are used during
discussions of thermodynamics. Operators must recognize the different types and
their interrelationships in order to understand thermodynamics.
EO 1.3
DEFINE the thermodynamic properties temperature
and pressure.
EO 1.4
DESCRIBE the Fahrenheit, Celsius, Kelvin, and
Rankine temperature scales including:
a.
Absolute zero temperature
b.
The freezing point of water at atmospheric pressure
c.
The boiling point of water at atmospheric pressure
EO 1.5
CONVERT temperatures between the Fahrenheit,
Celsius, Kelvin, and Rankine scales.
EO 1.6
DESCRIBE the relationship between absolute
pressure, gauge pressure, and vacuum.
EO 1.7
CONVERT pressures between the following units:
a.
Pounds per square inch
b.
Inches of water
c.
Inches of mercury
d.
Millimeters of mercury
e.
Microns of mercury
Temperature
Temperature is a measure of the molecular activity of a substance. The greater the movement
of molecules, the higher the temperature. It is a relative measure of how "hot" or "cold" a
substance is and can be used to predict the direction of heat transfer.
Temperature Scales
The two temperature scales normally employed for measurement purposes are the Fahrenheit (F)
and Celsius (C) scales. These scales are based on a specification of the number of increments
between the freezing point and boiling point of water at standard atmospheric pressure. The
Celsius scale has 100 units between these points, and the Fahrenheit scale has 180 units. The
zero points on the scales are arbitrary.
HT-01
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