test tommorow

What is the REFERENCE for gauge pressure?

Atmospheric Pressure

What gauge is referenced to ABSOLUTE ZERO?

Absolute

What gauge reads the DIFFERENCE between two measured pressures?

Differential

Which gauge is more ACCURATE? (absolute, differential, or vacuum)

Absolute

What is INFERRED measurement?

Some other variable is measured, then translated. (also called indirect)

Which is more RELIABLE and ACCURATE: mechanical or electrical gauges?

Electrical

Which is more EXPENSIVE: mechanical or electrical gauges?

Mechanical

What are 5 factors that affect a LIQUID'S PRESSURE?

Height
Weight
Temperature
Atmospheric Pressure
Mechanical Machines

What is the biggest factor that affects a GAS' PRESSURE?

Temperature

How do gases EXERT PRESSURE?

Equal pressure in all directions

What is the MEASUREMENT for atmospheric pressure?

14.7 psi

The HIGHER the elevation, the _______ the atmospheric pressure.

lower

How does a THERMISTOR work?

Changes electrical resistance when the temperature changes

How does a THERMOCOUPLE work?

Convert heat into a proportional voltage

How does a RESISTANCE TEMPERATURE DETECTOR (RTD) work?

Certain metals are used to detect temperature changes in order to adjust resistance

What are 2 METALS used in an RTD, and why are they used?

Nickel - most sensitive

Platinum - best for wider temperature ranges

Describe 2 characteristics of VOLUMETRIC FLOW RATE:

Measures the VOLUME of material that flows during specific period of TIME

Not measured directly, but INFERRED

Describe a characteristic of FLOW VELOCITY:

The DISTANCE a material travels per unit of TIME

Describe 2 characteristics of MASS FLOW RATE:

The WEIGHT of materials that flow during a specific period of TIME

Usually SOLIDS

What is a REYNOLD'S NUMBER (R Number)?

Number used to identify type of flow current

What are the 3 types of FLOW determined by the R NUMBER? (and their VALUES)

Laminar
2k or less

Transition
3k

Turbulent
7k-8k

What does LAMINAR flow look like?

Very streamline and uniform

What does TRANSITION flow look like?

Off center, but still straight

What does TURBULENT flow look like?

Swirls; not straight at all

What FLOW DETECTOR is this:

PADDLE wheels that rotate.
Uses TEE/SADDLE fittings.
HALL EFFECT causes voltage pulse.

ROTOR flow detector

What FLOW METER is this:

BLUNT OBJECT in flow path.
VORTICES develop.
PRESSURE CHANGES create pulses.

VORTEX flow meter

What FLOW METER is this:

Use a THERMISTOR.
Uses THERMAL CONDUCTIVITY.
TEMPERATURE affects RESISTANCE.

THERMAL flow meter

What METER is this:

Measures MASS FLOW.
U SHAPED tube VIBRATES from MAGNET.
KINETIC energy RESISTS vibration.

CORIOLIS meter

What FLOW METER is this:

Sound causes DOPPLER EFFECT.
Uses PIEZEOELECTRIC device.
Turns SOUND into ELECTRICITY.
Good for DIRTY liquids.

ULTRASONIC flow meter

What FLOW DETECTOR is this?

VOLUMETRIC FLOW into VOLTS.
Based on FARADAY LAW.
VOLTAGE PRODUCED = FLOW RATE.

ELECTROMAGNETIC flow detector

What is POINT LEVEL measurement? (2 characteristics)

Detects if interface is at a PREDETERMINED point

Detects using BOOLEAN signals

What is CONTINUOUS LEVEL measurement? (2 characteristics)

Locates interface within range of ALL POSSIBLE LEVELS at ALL TIMES

ANALOG signal between 4 and 20 mA

What kind of MEASUREMENT is this:

OBSERVE location of top of material

VISUAL measurement

What kind of MEASUREMENT is this:

DIPSTICK inserted into material

ROD GAUGE measurement

What kind of MEASUREMENT is this:

TRANSPARENT tube connected to side of vessel

SIGHT GLASS measurement

What kind of MEASUREMENT is this:

ROUND object riding on SURFACE of liquid

FLOAT TYPE measurement

What kind of MEASUREMENT is this:

WEIGHTED probe has BUOYANCY, tends to FLOAT; uses ARCHIMEDES' principle

DISPLACEMENT LEVEL measurement

What kind of MEASUREMENT is this:

OLDEST method, also called PURGE, uses DIP TUBE and BUBBLER PIPE

BUBBLER measurement

What kind of MEASUREMENT is this:

Uses MOTION to measure level by SPINNING, it is INVASIVE

PADDLE WHEEL measurement

What kind of MEASUREMENT is this:

Pressure detector using INDIRECT/INFERRED measurement, material exerts its OWN WEIGHT

HYDROSTATIC HEAD LEVEL measurement

What kind of MEASUREMENT is this:

Uses 2 PRESSURE DETECTORS, one placed at BOTTOM, other placed in VAPOR SPACE

DIFFERENTIAL PRESSURE measurement

What kind of MEASUREMENT is this:

Uses INFERRED measurement value of WEIGHT, also is NONINVASIVE and very ACCURATE

WEIGHT measurement

What kind of SENSOR is this:

Detect presence of CONDUCTIVE LIQUID, a type of SINGLE POINT measurement

CONDUCTIVE PROBE sensor

What kind of SENSOR is this:

Uses DIELECTRIC, a type of CONTINUOUS LEVEL measurement

CAPACITIVE PROBE sensor

What kind of SENSOR is this:

Creates ULTRASONIC WAVES made by OSCILLATOR, amount of TIME waves travel is MEASURED

ULTRASONIC sensor