Chapters 8,9,10

Front 1

A vibration measuring device (e.g., piezoelectric type).

Back 1

Accelerometer

Front 2

The operating range within which a piece of rotating equipment can operate without causing excessive wear to the bearings, or other types of catastrophic failure

Back 2

acceptable limits

Front 3

Where a solid material is weighed as it is conveyed on a moving belt (conveyor) and an instantaneous weight measurement is taken and the rate of motion of the belt is known

Back 3

mass flow rate

Front 4

A dangerous condition that can occur in a turbine or other type of equipment that moves too fast

Back 4

overspeed

Front 5

Linear speed expressed in distance per unit of time (e.g., feet per second)

Back 5

Rectilinear speed

Front 6

Number of revolutions per unit of time (e.g., revolutions per minute or rpms)

Back 6

Rotational speed

Front 7

The distance traveled per unit of time irrespective of direction (e.g, feet per second)

Back 7

speed

Front 8

A device that measures speed; comprised of a speed sensor and a readout/receiving device

Back 8

speed monitor

Front 9

speed with a specific direction

Back 9

velocity

Front 10

the periodic motion of an object

Back 10

vibration

Front 11

a device used to measure displacement, velocity, or acceleration due to vibration; consists of a pickup device, an electronic amplification circuit, and an output meter

Back 11

vibration meter

Front 12

a device used to sense the effects of vibration by sending a signal to a meter or monitor, or to shut down a device if operating limits are exceeded.

Back 12

vibration sensors or monitors

Front 13

How close a measurement corresponds to its true value

Back 13

accuracy

Front 14

preset mathematical functions calculated in a controller that can be mechanical, analog, or digital. The three most common output functions deal with proportional (P), integral(I), derivative, (D) tuning)

Back 14

algorithms

Front 15

sensing, measuring, comparing, calculating, correcting and manipulating

Back 15

basic control functions

Front 16

when a control loop has feedback(e.g. controller in automatic mode)

Back 16

closed control loop

Front 17

a component of a controller that compares the measurement to a predetermined setpoint

Back 17

comprator

Front 18

the control loop component that receives the appropriate signal from the transmitter and compares the signal to a desired value (setpoint); if there is a difference, then the output of the comparison causes a calculation to be performed to cause a corrective response by the controller output signal to the final control element

Back 18

comparing, calculating, and correcting) elecement

Front 19

a process variable that is sensed to initiate the control signal.

Back 19

controlled variable

Front 20

an instrument that receives a signal from the transmitter and compares it to a setpoint, and produces an output to a final control element

Back 20

ctonroller

Front 21

the control loop component that converts the sensed process variable and transmits and transmits the measured signal

Back 21

converting and transmitting element

Front 22

a device that receives information in one form of an instrument signal and changes it into another form of another instrument signal

Back 22

converting device

Front 23

the accuracy of the instrument (+/-) full scale

Back 23

device error

Front 24

characterized by data that is represented as coded information in the form of binary numbers; used to transmit data to and from field transmitters on a twisted pair of wires; may also be between computers and computer components.

Back 24

digital signal

Front 25

either an analog or digital signal; current or voltage singal

Back 25

electronic signal

Front 26

the most common type of control loop where the change caused by the output of the controller is fed back to the process providing a self-regulating action

Back 26

feedback loop

Front 27

the last active device in an instrument control loop; directly controls the manipulated variable; usually a control valve, louver, or an electric motor

Back 27

final control element

Front 28

a standard bias been added to the instrument signal (e.g., pneumatic 3-15 psig or electronic 4-20 mA) instead of reading zero the reading is 3 psig or 4mA

Back 28

live zero

Front 29

the accumulated error of each device in the loop; calculated as the square root of the sum of the sum of the squares of individual device accuracy

Back 29

loop error

Front 30

the final element (e.g., control valve) is manipulated by the corrective response of the controller output so that the process variable is maintained at the appropriate setpoint value

Back 30

manipulated eleement

Front 31

a process variable that is measured

Back 31

measured variable

Front 32

a way of mechanically transmitting the motion of a primary sensor to controlling mechanism; convey linear or rotary motion by using a pivoting crnk

Back 32

mechanical link

Front 33

when a control loop does NOT have feedback (e.g., controller in manual mode)

Back 33

open control loop

Front 34

one wire per b it or 64+ wires for a 64-bit binary word; used primarily in short distance (a few feet)

Back 34

parallel data communication

Front 35

an instrument communication with a range of 3-15psig; must have an air supply; has a lag time associated within the signal; relatively short transmission distances

Back 35

pneumatic signal

Front 36

how close repeated measurements are versus the action; reproducibility; the closeness of repeated measurements of the same quantity; the agreement between the numerical values of two or more measurements made in the same way and expressed in terms of deviation

Back 36

precision

Front 37

the act of regulating one or more process variables so that a product of a desired quality can be produced

Back 37

process control

Front 38

the difference between setpoint and process variable (SP-PV)

Back 38

process error

Front 39

the act of detecting

Back 39

sensing

Front 40

the control loop component that detects, or senses, the process variable

Back 40

sensing element

Front 41

two data wires; the most common means of communication used between plant equipment

Back 41

serial data communication

Front 42

the desired process value

Back 42

setpoint

Front 43

a device that transmits a signal from one device to another

Back 43

transmitter

Front 44

a sensing element that can stand alone or is individually distinct; connected to a transmitter by sensor wires

Back 44

discrete sensing element

Front 45

a tube that is usually made of stainless steel and allows the process variable to be sensed by the sensor located in the transmitter

Back 45

impulse tubing

Front 46

a range of ordered marks that indicate the numerical values of the process variable

Back 46

instrument scale

Front 47

where the sensing element is a physical part of the transmitter

Back 47

integrally mounted sensing element

Front 48

a linear relationship between two scales (input versus output)

Back 48

linear scaling

Front 49

the number at the bottom of the scale

Back 49

lower range value (LRV)

Front 50

one number that is the difference between the upper and lower range values (URV and LRV) on ascale

Back 50

operating range

Front 51

the act of equating the numerical value of one scale to its mathematically proportional value on another scale

Back 51

scaling

Front 52

detects the process variable; can be an integral part of a transmitter

Back 52

sensor

Front 53

part of transmitter that effectively converts the process variable into a standard instrument signal; a device converts one energy form into another

Back 53

signal converter transducer

Front 54

the algebraic difference between the URV minus the LRV of scale expressed as one number.

Back 54

span

Front 55

the language that instruments use to communicate between one another (4-20 mA, 3-15 psig, or digital)

Back 55

standard signal

Front 56

the number at the top of the scale

Back 56

Upper range value (URV)