Definitions Flashcards
FCE stands for
Final control element
CO stands for
Controller output
PV stands for
Process Variable
UTP stands for
Upper trip point
LT stands for
Level transmitter
LTP stands for
Lower trip point
Def : ripple
A variation in dc voltage magnitude
Def : seebeck effect is
Redistribution of electrons when one end of the conductor is heated
Def : law of intermediate metals?
The introduction of a third metal into a cct has no effect on Eo if the junctions created by 3rd metal are the same temp
Rtd temp coefficient def
Temp resistance compared to temp change
Def ice point (rtd)
Ohms at 0’C
Def : control algorithm
A mathematical representation of the control action being performed
Def : Control action (P)
Control action where there is a continuous linear relation between output and input
Def : control action, integral (reset)
The RATE OF CHANGE of the output is proportional to the input
Def : control action, derivative (Rate) (D)
The RATE OF CHANGE of the output is proportional to the RATE OF CHANGE of the input
Def : control action, proportional-plus-integral (PI)
The output is proportional to the linear combo of the input and time integral of the input
Def : control action, proportional-plus-derivative(PD)
The output is proportional to a linear combination of the input and the time rate of change of the input
Def : control action, proportional- plus -integral-plus -derivative
The output is proportional to a linear combo of the input , the time integral of the input and the rate of chang of the input
Def : stable control
The PV eventually reaches a constant value after an error occurs
Def : unstable control
The PV oscillates wildly after an error occurs
Def : controlled variable (CV)
A process variable (PV) that is to controlled at a desired state by manipulate another process variable
Def : negative feedback
Returning part of an output signal and using it to reduce the value of the output signal
Def : stability
Freedom from undesirable deviation
Def : step change
The change from 1 value to another in a single increment of negligible time
Def : transient
The behavior of a variable during transition between 2 steady states
Def : damping
Reduction of oscillations in response to a step change
Def : bias
The CO required to maintain the balance between SP and PV
Def : offset
Solution?
Controller thinks the 2 are @ the same point. Caused by spring not matching controller.
Solution: adjust spring
COo is
Bias spring
Def : proportional gain?
Adjusted by?
- regulates how much CO changes after an error
- physical knob
Def : pump head
The height of a vertical column of liquid that the pump holds up
Def NPSH
Pump
Net positive suction head
Measure of the pressure at the pump end of the outlet
Def : incident radiation
The energy hitting a body in the form of waves or particles
Def : absorbed radiation
Radiant energy absorbed through a body
Def : reflected radiation ?
Symbol?
Is the radiant energy reflected by a body
Symbol R
Def : transmitted radiation?
Symbol?
Transmitted through a body
Symbol T
I = A + R + T = 1 is for
Sum of incident radiation
Def : Emissivity
The ratio of radiant energy an object emits dived by the amount of energy a black body emits at the same temp
Def : blackbody
Absorbs all radiation and radiates more than any other
Controllers
ADC is
Analog to digital
Controllers
DAC is
Digital to analog
Def :Grey body
Object with emissivity of less than 1. Same at all wave lengths
Def : non grey body
Emissivity varies varies with wave length and temp
Def flocculation
Chemical process to remove coloital and spended solids ( particles attract of the colotals)
Def : conduction (heat)
Heat transfer from high heat to low heat in same object
Def : convection (heat)
Heat transfer from 1 location to another
Def : radiation ( heat)
Heat transfer through space
Def : crystallization
Separates solids from liquids by dropping heat till solids precip out as crystals
UEL IS
Upper explosive limit
OEL is
Occupation exposure limit
LEL IS
lower explosive limit
Vena contracta
Point of lowest pressure and highest velocity
KPaa
Kp atmospheric
KPabs
Absolute pressure (all)
KPag
Gage pressure
HUH
