Module 1: Pressure Measurement Flashcards
Organizations that transform one substance into another
PROCESS INDUSTRIES
Common reasons process industries measure pressure
- Safety
- Process Efficiency
- Cost-savings
- Inferred measurement of other variables
Inferred measurements of other variables
- How 2 or more liquids in a tank interface
- Rate of flow
- Level of fluid
- Density of fluid
Amount of force applied over defined area
PRESSURE
___ increases if force increases or area over force decreases
PRESSURE
3 Factors influencing pressure exerted by liquid
Depth of liquid, density of liquid, pressure on the surface of liquid
Pressure is affected by the —-, rather than the volume of liquid
DEPTH
Mass of substance per unit volume
DENSITY
higher density liquids are — per unit volume
HEAVIER
Ratio of density of liquid to density of water at same temperature
SPECIFIC GRAVITY
Pressure exerted above column of liquid being measured
PRESSURE ON THE SURFACE OF A LIQUID
2 Factors affecting pressure exerted by gas
- Volume of container
- Temperature of gas
Liquids and gases are referred as
FLUIDS
describes how pressure of gas tends to increase as volume of container decreases
BOYLE’S LAW
Absolute pressure inversely proportional to volumw
BOYLE’S LAW
Describes how gases tend to expand when heated
CHARLE’S LAW
Two categories of pressure units
- Units of force over area
- Units referenced to column of fluid
3 reference pressures
ABSOLUTE
GAUGE
DIFFERENTIAL
Compared measured pressure to a perfect vacuum. Can never be negative
ABSOLUTE PRESSURE
Uses the pressure of surrounding atmosphere as reference pressure
GAUGE PRESSURE
Uses a second process pressure as reference pressure. It is also often used to infer rate of flow thru pipe
DIFFERENTIAL PRESSURE
3 TYPES OF MEASURABLE PRESSURE
HEAD PRESSURE
STATIC PRESSURE
VAPOR PRESSURE
known as HYDROSTATIC PRESSURE
HEAD PRESSURE
Pressure exerted by a column of fluid
HEAD PRESSURE
