What is the basic principle of proximity measurement
What type of signal generator is a proximitor
Alternating current (AC) generator
Sound wave generator
Radio Frequency (RF) signal generator
Direct current (DC) generator
What does axial (thrust) movement describe?
The small movement of a shaft toward and away
The twisting motion of the shaft
The vibration of the machine relative to free space
movement of a shaft in the direction of its axis of rotation
In proximity measurement, what variable is directly proportional to the electromagnetic field strength
Shaft imbalance
Distance from the probe tip to the target surface
Lubrication pressure
Bearing temperature
Which device is used to measure the movement of the machine itself (absolute vibration)
Accelerometer
Micrometer
Proximity probe
Seismic velocity transducer
In what unit is vibration frequency commonly measured
Volts (V)
Cycles per second (cps)
Degrees (°)
Newtons (N)
What does the emergency shutdown system do
Adjusts the vibration amplitude
Reduces noise levels
Starts data acquisition
Performs an emergency shutdown in dangerous situations
As the target surface moves away from the probe tip, what happens to the electromagnetic field strength
It disappears completely
It remains unchanged
It decreases
It increases
What does relative vibration describe
The twisting of the shaft around its axis
The movement of a shaft inside the bearing
The movement of the shaft toward a fixed reference point
The vibration of the shaft and the machine relative to free
Which vibration characteristic indicates the rotor’s position at a specific moment
Frequency
Root Mean Square (RMS)
Amplitude
Phase Angle
What happens to the eddy current when the target surface moves away from the probe tip
It increases
It reverses direction
It decreases
It stays constant
What happens when rotating equipment is operating properly?
The shaft speed gradually decreases
The machine stops moving completely
Forces and energy levels become uncontrolled
Forces and energy levels remain under control
When does the alarm system activate
When the machine is not running properly
When the shaft speed increases
When the power supply is turned off
When the machine is perfectly balanced
Where is the fixed reference point located when measuring radial vibration
At the shaft coupling
On the motor casing
On the drive belt
In the bearing wall
What does the change in current flowing through the probe coil indicate
speed of shaft rotation
The vibration frequency
load on the bearings
gap between the probe tip and the conducting material
What is one of the roles of the monitoring rack
To control the lubrication flow
To provide mechanical alignment
To replace damaged gears
To receive and condition transducer signals and send outputs
What is misalignment in rotating equipment
driver and driven device have different centers of rotation
machine vibrates relative to free space
shaft moves toward and away from its bearings
shaft rotates at a very high frequency
What does radial vibration describe?
small movement of a shaft toward and away from its bearings
The twisting motion of a rotating shaft
The movement of a shaft along its axis
The vibration of the machine relative to free space
What type of misalignment is shown in the diagram
Shaft balancing
Angular misalignment
Offset misalignment
Radial misalignment
How do worn bearings affect machine vibration
They increase the amount of vibration
They decrease the vibration amplitude
They completely eliminate vibration
They have no effect on vibration
What can happen if loose mounting bolts are not corrected
Increased lubrication efficiency
Improved shaft alignment
Complete destruction of related equipment
Reduced vibration levels
The output of the preamplifier in a proximity probe is proportional to
frequency of vibration
tension in the belt
displacement between the probe tip and a conducting surface
load on the shaft
What can happen if a machine vibrates excessively and forces are not under control?
The equipment automatically self-repairs
Reduction in noise level
Severe damage and release of high-pressure gases
The machine becomes more efficient
What do electric motors, pumps, compressors, and turbines have in common?
They produce no vibration during operation
They all contain a high-speed rotating shaft
They all operate at very low speed
They do not require electrical power
Which condition causes a shaft to move inside its bearings and contact the bearing walls
Out of balance
Axial movement
Proper lubrication
Radial misalignment
What is vibration?
A rapid back-and-forth movement
A slow circular motion around a shaft
A rapid running movement
A rapid machine movement
What does Peak-to-Peak (Pk-Pk) measure in vibration
The distance from a negative peak to a positive peak
The maximum movement of the wave from zero
The average squared value of the waveform
The number of cycles per second
What tool is recommended to check the tension of drive belts
Tension meter
Tachometer
Lubrication gauge
Vibration probe
What does Root Mean Square (RMS) represent in vibration
The number of cycles per second
square root of the average of the squared values of waveform
The distance from a negative peak to a positive peak
The maximum movement of the wave from zero
What is a good method of determining the condition of rotating equipment?
Measuring the vibration produced during operation
Observing the paint color of the machine
Checking the oil level
Monitoring the power supply voltage
What does the RF signal from the proximitor do at the probe tip
Produces an electromagnetic field
Increases shaft alignment
Reduces bearing load
Generates lubrication pressure
Why is monitoring axial (thrust) movement important
increases lubrication efficiency
lowers the machine’s power consumption
reduces the machine’s operating noise
excessive axial motion can cause serious machine damage
What type of misalignment is shown in the diagram
Shaft balancing
Angular misalignment
Radial misalignment
Offset misalignment
What does amplitude represent in vibration
The magnitude of the vibration
The speed of the vibration
The direction of the vibration
The angle of the vibration
What does absolute vibration describe
The distance between negative and positive peaks
The twisting of the shaft around its axis
vibration of shaft and the machine relative to free space
movement of the shaft inside the bearing
What is another name for proximity probes
Eddy current probes
Seismic velocity probes
RMS detectors
Piezoelectric probes
What is the function of transducers in vibration monitoring systems
They lubricate the bearings automatically
They generate electricity for the machine
They increase the shaft rotation speed
They sense vibration and convert it into an electrical signa
hat does the proximitor’s electronic circuitry produce when the proper voltage is applied?
A thermal wave
An RF signal
A static charge
A mechanical vibration
What is one main purpose of equipment vibration monitoring systems?
To provide early warning of mechanical problems
To reduce the machine size
To increase machine noise
To replace worn-out belts automatically
What action can equipment vibration monitoring systems take when problems arise
Speed up the machine
Improve lubrication by itself
Increase the shaft rotation
Automatically shutdown the equipment
What does the phase angle of vibration describe
The speed of the vibration
The magnitude of the vibration
The location of the rotor at a particular instant
The distance from peak to peak
Which of the following can endanger equipment and personnel when vibration problems occur?
Extra cooling systems
Broken parts, belts, and gears
Improved shaft alignment
Increased lubrication
What does the coil in a proximity probe produce
An electromagnetic field
A hydraulic pressure
A thermal signal
A sound wave
What does a proximity probe consist of
A tension meter attached to a belt
A magnet attached to a rotating shaft
coil of wire wound around metal rod connected to preamplifie
A sleeve bearing filled with oil
What does Peak Amplitude (Pk) represent in vibration?
The total distance from a negative peak to a positive peak
The maximum movement of the wave from zero
The frequency of the wave in cycles per second
The square root of the average squared values of the wavefor
What does the frequency of vibration represent
The size of the vibration
The power consumed by the machine
The distance between peaks of a wave
How fast a machine is vibrating
What can insufficient lubrication between a shaft and a sleeve bearing cause
Vibration
Perfect alignment
Reduced machine speed
Lower energy consumption
What is one purpose of the data acquisition system
To provide early warning and collect diagnostic data
To control shaft alignment
To generate high-pressure gas
To perform emergency shutdowns