Important Inst Q & A

8/10/2019 Important Inst Q & A

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INSTRUMENT QUESTION & ANSWERS

INTRODUCTION:

It is the branch of engineering which deals with the measurement, monitoring, display etc. of the several ofenergy exchanges which take place during process operations. "In short Instrumentation is the study ofInstrument."

INSTRUMENT:

Instrument is a device which is used to measure, monitor, display etc. of a process variable.1. What are the process Variabes!The process Variables are: low. !ressure. Temperature. evel. #uality i.e. $ %&, '%&, p( etc.

". De#i$e a the process Variabe a$% state their $it o# 'easre'e$t. !

(o):)ny fluids or li*uids flowing from one place to another place is called flow and it is defined as volumeper unit of time at specified temperature and pressure

'onditions, is generally measured by positive+displacement or rate meters.U$its:kg hr, litter min, gallon min, m- hr, m- hr. /0ases1

*ressre:It is defined as orce per unit )rea. ! 2 )U$its :bar, !ascal, kg cm&, lb in&.

+e,e:The height of the water column, li*uid and powder etc., at the desired measurement of height betweenminimum level points to maximum level point is called level. The measurement principle is, head pressuremethod.U$its:3eters, mm, cm, percentage.

Te'peratre:It is the degree of hotness or coldness of a body is called temperature.U$its :4egree 'entigrade, 4egree ahrenheit, 4egree 5elvin, 4egree 6ankin.

Qait-:It deals with analysis./ p(, $ '%&, $ 7&, 'onductivity, Viscosity 1

. What are the pri'ar- ee'e$ts se% #or #o) 'easre'e$t!

The primary elements used for flow measurement are: %rifice !late. Venturi tube. !itot tube. )nnubars. low o88le. 9eir lumes.

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A

/. What are the %i##ere$t t-pes o# ori#ice pates a$% state their ses!The different types of orifice plates are: 'oncentric. Begmental. Cccentric. #uadrant Cdge.

Co$ce$tric:

The concentric orifice plate is used for ideal li*uid as well as gases and steam service. This orifice plate betaratio fall between of 7.=; to 7.>; for li*uids and 7.&7 to 7.>7 for gases, and steam. Dest results occurbetween value of 7.< and 7.E. Deta ratio means ratio of the orifice bore to the internal pipe diameters.

/


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#uadrant edge orifices produce a relatively constantcoefficient of discharge for services with low6eynolds numbers in the range from =77,777 downto ;,777.

/ ig < 1. 2o) %o -o i%e$ti#- a$ ori#ice i$ the pipe i$e!)n orifice tab is welded on the orifice plate which extends outer of the line giving an indication of the orificeplate.

3. Wh- is the ori#ice tab pro,i%e%!The orifice tab is provided due to the following reasons. Indication of an orifice plate in a line. The orifice diameter is marked on it. The material of the orifice plate. The tag no. of the orifice plate. The mark the inlet of an orifice.

A%,a$ta0es a$% Disa%,a$ta0es o# Ori#ice *ates)dvantages of orifice plates include: (igh differential pressure generated Cxhaustive data available ow purchase price and installation cost Casy replacement4.What is 5er$oi6s theore' a$% )here it is appicabe!DernoulliGs theorem states the "total energy of a li*uid flowing from one point to another remains constant."It is applicable for non compressible li*uids.

7. 2o) %o -o i%e$ti#- the 2. *. si%e or i$et o# a$ ori#ice pate i$ i$e!The marking is always done (. !. side of the orifice tab which gives an indication of the (. !. side.

8. 2o) %o -o caibrate a D. *. tra$s'itter!The following steps are to be taken which calibrating:=. )dHust 8ero of the Txr.&. Btatic pressure test : 0ive e*ual pressure on both sides of the transmitter. Jero should not shift. If it isshifting carry out static alignment.-. Vacuum test : )pply e*ual vacuum to both the sides. The 8ero should not shift.


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+ii% i$es : %n li*uid lines the transmitter is mounted below the orifice plate because li*uids have aproperty of self draining. Ori#ice pate

(o) %irectio$

*ri'ar- isoatio$ ,a,e

= +IQUID SERVICE >

)a- 'a$i#o% ,a,e

(o) tra$s'itter

K +


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Stea' Ser,ice Co$%e$sate pot

)a- 'a$i#o% ,a,e

? @ (o) tra$s'itter

1". Dra) a$% epai$ a$- #o) co$tro oop !

CB,*ositio$er

Ori#ice pate

*NEUMATIC> *ri'ar- isoatio$ ,a,e =(+OW CONTRO+ +OO*>

AIR SU**+ (RC

)a- 'a$i#o% ,a,e

(o) tra$s'itter AIRSU**+

1. A$ operator tes -o that #o) i$%icatio$ is 'ore; 2o) )o% -o start checi$0! irst flushing the transmitter. lush both the impulse lines. )dHust the 8ero by e*uali8ing if

necessary. If still the indication is more then. 'heck .!. side for choke. If that is clean then. 'heck the leaks on .!. side. If not. 'alibrate the transmitter.

1/. 2o) %o -o %o a ero chec o$ a D.*. tra$s'itter !'lose one of the valve either (.!. or .!. open the e*uali8ing valve. The %! should read 8ero.

1. 2o) )o% -o %o


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Bame repeat for .!. side by connecting pump to (.!. side, keeping e*uali8er open and (.!. sideisolation valve closed.

'lose the seal pot vent valves. 'lose e*uali8er valve. %pen both the primary isolation valves.

13. 2o) %o -o cacate $e) #actor #ro' $e) ra$0e si$0 o% #actor a$% o% ra$0e!

#= L M!= #= 2%ld flow F #&2 ew flow#& L M!& L M!=2 %ld 4! L M!&F Ne)4!

#&NM!= 2 #=N L M!&

#=GM!& #& F L M!=

%ld flow N new 4!ew flow 2

L%ld 4!

%! $ 2 low, I! $ 2 M!( F L M! x =7 /or1 %! $ 2 L I!$ O =714. 2o) )i -o ,e$t air i$ the D.*. ce! What i# sea pots are se%! )ir is vented by opening the vent plugs on a li*uid service transmitter. %n services where seal pots are used isolate the primary isolation valves and open the vent valves.

ill the line from the transmitter drain plug with a pump.

17. Wh- #o) is 'easre% i$ sare root!low varies directly as the s*uare root of different pressure 2 5 s*uare root of 4!. Bince this flow variesas the s*uare root of differential pressure the pen does not directly indicate flow. The flow can be determinedby taking the s*uare root of the pen. Bay the pen reads ;7$ of chart.

18. What is absote pressre!)bsolute pressure is the total pressure present in the system)bs. pressure 2 0auge pressure K )tm. pressure.

"9. What is absote ero pressre!

)bsolute 8ero 2 >E7 mm (g Vacuum."1. What is the 'ai'' Vac'!The maximum Vacuum 2 >E7 mm (g.

"". What is Vac'!)ny pressure below atmospheric pressure is vacuum.

At' F 439 '' Hero Vac'&;?@?.doc E


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Hero E7 mm Vacuum /or nearest1 and adHust 8ero. )pply -E7 mm Vacuum adHust span. />E7 + -E7 2


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=. G'G type Dourdon tube.&. 'onnecting link.-. Bector gear.. 4ial.Uses o# 2air Spri$0 : (air spring serves two purposes namely To avoid backlash error /eliminate any play into linkages1. It serves as a controlling tor*ue.

+ E V E +

"8. 5rie#- epai$ the %i##ere$t 'etho%s o# e,e 'easre'e$t!There are two ways of measuring level:=. 4irect&. Indirect. T)!C 3C)BF6C=. Direct e,e 'easre'e$t:

/a1 Dob and tape: TAN (ighest point reached by) bob weight and measuring li*uidTape provide the most simple)nd direct method of3easuring li*uid level. 4istance to be measured

+IQUID after tape is taken out ofTank.

Dob /weight1

/b1 Bight glass:

This consists of a graduated glass tube mounted on the side of the vessel. )s the level of the li*uid in thevessel change, so does the level of the li*uid in the glass tube.

I$%irect e,e 'easre'e$t:

/)1 !ressure gauge:

This is the simplest method, for pressure gauge is located at the 8ero level of the li*uid in the vessel. )ny risein level causes an increase of pressure which can be measured by a gauge.

/b1 !urge system:In this method a pipe is installed vertically with the open and at 8ero level. The other end of the pipe isconnected to a regulated air r supply and to a pressure gauge. To make a level measurement the air supply isadHusted so that pressure is slightly higher than the pressure due to height of the li*uid. This is accomplishedby regulating the air pressure until bubbles cab be seen slowly leaving the open end of the pipe. *ressre 0a0e As e,e 0a0e

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Air re0ator

N "pr0e Air spp- Rota 'eter

The air pressure to the bubbler pipe is minutely inCxcess of the li*uid pressure in the vessel, so that

)ir pressure indicated is a measure of the level inThe tank.

The method above is suitable for open tank applications. 9hen a li*uid is in a pressure vessel, the li*uidcolumn pressure canGt be used unless the vessel pressure is balanced out. This is done through the use ofdifferent pressure meters.

/c1 4ifferential pressure meter:

'onnections are made at the vessel top and bottom, and to the two columns of the 4.!. meter. The topconnection is made to the .!. column of the transmitter and the bottom to (.!. column of the transmitter.The difference in pressure in the vessel is balanced out, since it is fed to both the column of the meter. Thedifference in pressure deducted by the meter will be due only to the changing, level of the li*uid.

/d1 4isplacer type level measurement:

The leveltrol is one of the most common instruments used measuring level in closed tanks. This instrumentworks of )rchimedes principle. The displacer in immersed in the li*uid due to which there is loss of weightdepending on the specified gravity of the li*uid. This displacer hangs freely on a knife transmitted to the

pneumatic or electronic counterpart at the other end.

9. Epai$ ho) -o )i 'easre e,e )ith a %i##ere$t pressre tra$s'itter.The bottom connection of the vessel is connected to high pressure side of the transmitter.

4ifferent !ressure 2 ( O 4

2D

2* +* K +

D B * TRANSMITTER

This difference pressure is applied to (.!. side of the transmitted and calibrated.

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J 2 =7 inches 02 7.? 0B2 7.@ Bpan 2 /-771 /7.?1 2 &


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The 6V should be selected so that the displayed result represents the 8ero or sub+8ero value of the process variable /e.g. 7+=;7tonsday, 7+=77$ level, 7+=7 bar /ga1, +=K- bar /ga1, 7+;77 R', +;7K;7 R' etc.1. Clevated 8eros /=77+-77 tonsday, =77+&77 R'1 should be avoided.

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Cose ta$ )ith )et e0: Bpan 2 /O1 /01(9at minimum level 2 / P 1 / 01 S / d 1/ 0B 1(9at maximum level 2 / O K P 1 / 01 S / d 1 / 0B 1 9here: 02 Bpecific gravity of tank li*uid 0B2 Bpecific gravity of tank li*uid (9 2 C*uivalent head of waterO, P and J are shown in fig.

%

Cxample : O 2 -77 inches P 2 ;7 inches d 2 ;77 inches 0 2 7.? 0B 2 7.@Bpan 2 / -77 1 / 7.? 1 2 &


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/. What is pr0e e,e s-ste'!This method is also known as bubbler method of level measurement. ) pipe is installed vertically with itsopen end at the 8ero level. The other end of the pipe is connected to a regulated air supply and to a pressuregauge or to ! transmitter. To make a level measurement the air supply is adHusted so that pressure is slightlyhigher than the pressure due to the height of the li*uid. This is accomplished by regulating the air pressureuntil bubbles can be seen slowly leaving the open end of the pipe. The gage then measures the air pressureneeded to over come the pressure of the li*uid.U ! 2 ( O 4USE: %n for corrosive li*uids where the transmitter cannot be directly connected to process eg... )cids,Bome organic li*uids.

. Epai$ the )ori$0 o# a e,etro.&;?@?.doc =


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The leveltrol is used for measuring level of li*uids in a closed vessel.=. !6I'I!C. : It works on )rchimedes principle "The loss in weight of a body immersed in a li*uid is

e*ual to amount of li*uid displaced by the body". The leveltrol basically consists of the following :&. 4IB!)'C6:It is consists of a cylindrical shape pipe sealed and filled inside with sand or some weight.

The purpose of this is to convert change in level to primary motion. The variation in buoyancy resultingfrom a change in li*uid level varies the net weight of the displacer increasing or decreasing the load onthe tor*ue arm. This change is directly proportional to change in level and specific gravity of the li*uid.

-. 6C)P:)mplifies pressure variations at the no88les.


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4CBITP d

4CBITP 4

%n a level set the difference of two specific gravities.

8. 2o) )i -o caibrate a e,etro i$ the #ie%!

4isplacer chamber

evel transmitter.

Transparent !.V.' tube

'alculation W = If the calibrating li*uid is water: !rocess i*uid 4ensity =X 4isplacer height 2 mm of (&%.

'alculation W & If the calibrating li*uid is other li*uid: !rocess i*uid 4ensity 'alibrating li*uid density X4isplacer height 2 mm of (&%. /'alibrating li*uid height in mm1.

=. irst close both the primary isolation valves and drain the li*uid inside the chamber.&. )dHust the 8ero to get 7$ output.-. 'onnect a transparent !V' tube to the drain point as shown in hook up.


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-. 'heck linearity.

4isplacer length: in mm4ensity ow : dl in 5g =4ensity (igh : 4( in 5g =)larm Trip point $: O(( Trip !oint: P in mm

/1. 2o) )i -o app- )t. test caibratio$ to a e,etro.

9t. test calibration method:=. 6emove the displacer from the tor*ue arm.&. )pply e*uivalent weight on the tor*ue arm that is e*ual to the wt. of the displacer. )dHust 8ero $

output.-. or Bpan : V 2 r&h

oss in weight 2 9t. of float + wt. of the float immersed in li*uidoss in weight 2 Y wt. of float + Vol. x d ZBpan wt. 2 /wt. of float + oss in wt.1r 2 radius of the displacer.h 2 ht. of displacer.


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/7. Epai$ the )ori$0 o# a$ E$ra# e,e 0a0e!The Cnraf precise level gauge are based on servo powered null+balance techni*ue. ) displacer serves as acontinuous level sensing element.!rinciple:) displacer with a relative density higher than that of the product to be measured, is suspended from astainless steel wire D, that is attached to a measuring drum. ) two phase servo meter controlled by acapacitive balance system winds or unwinds the measuring wire until the tension in the weighing springs is inbalance with the weight of the displacer partly immersed in the li*uid. The sensing system in principlemeasures the two capacitance formed by the moving center sensing rod C provided with two capacitor plates

and the side plates. In balance position the capacitances are of e*ual value. ) level variation will a differencein buoyancy of the displacer. The center sensing rod will move in the direction of one of the side capacitorplates. This causes a difference in value of these capacitances. Dy an electronic circuit this change is detectedand integrated. 4uring the rotation of the servo motor the cam driven transmitter continuously change thevoltage pattern to a remote indicator of which the receiver motor drives a counter indicating level variation.

T E M * R E T U R E

/8. What are the %i##ere$t 'etho%s o# te'peratre 'easre'e$t! Epai$.The different methods of temperature measurement are:=. 3echanical &. Clectrical.Mecha$ica 'etho%s:1. Mercr- i$ 0ass ther'o'eters: This consists of a glass tube of very fine bore Hoined to a reservoir at thebottom and sealed at the top. ) measured *uantity of mercury is the enclosed. 9hen the thermometer isheated the mercury expands much more than the glass and is therefore forced to rise up in the tubing ) scaleis fixed at the side.

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". 5i'etaic Ther'o'eter :Two metals whose coefficient of linear expansion is different are welded androlled together to the desire thickness. The actual movement of a bimetal is its flexivity with one end fixed, astraight bimetal strip%e#ects i$proportion to its temperature, to the s*uare of its length and inversely withits thickens.. *ressre Spri$0 Ther'o'eters: Thereare four classes of pressure spring thermometers.=. i*uid filled 2 class =&. Vapor pressure 2 class &-. 0as filled 2 class -


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Ther'ocopes T-pes a$% Ra$0e:

Type T' !ositive wire color egative wire color 6ange 8 / [ 1 Iron 9hite 'onstantan 6ed +-77 to=6t. 2 6esistance of Temperature to measured.6o. 2 6esistance of 8ero temperature.\ 2 'o. off of thermal /expansion1.t 2 Temperature to be measured.These metals have a positive temperature co+efficient of expansion. Therefore resistance increases as the

temperature increases.

Types of material used: /=1 !latinum /&1 ickelThese metals have a positive temperature co+efficient of expansion. Therefore resistance increases as thetemp. Increases.

Cacatio$ o# Resista$ce or *t199.6o. 2 =77O for platinum 2 7.77-?; c.To calculate 6esistance at =77Gc.6=77 2 =77 Y=K /-?.; x =7 < x =771Z 2 =77 K /=77 x 7.-?;16=77 2 =-?.;Resista$ce at 1996c F 17.

9. What is *t 199 'ea$!!t=77 means =77 %(3B at 7G' for a platinum resistance bulb.

1. What is t)o )ire a$% three )ire R.T.D. s-ste'!Two wire 6 .T .4. system:Two wire 6T4 system use for short distance like a compressor field local panel.

Three wire Bystem:Three wire systems use for long distance coke a field to control 6un.The third wire is used for compensation of lead wire resistance.

T)o@)ire R.T.D Three@)ire R.T.D

? @ ? @

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0al

0al


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R1 R" R1R"

R R

R.T.D R.T.D". Dra) a pote$tio'eter te'p. Measri$0 circits a$% epai$ its!

Ther'oCope T)o %i##ere$t si0$a AM*

UN $o) Si0$a

Ser,o baa$ci$0 'otor

Meas. Co$sta$t ,ota0e $o)$ Circit si0$a si0$a

O*ERATION:The input to the instrument is a measurement of some in the processes using a sensing element /such asthermocouple1 or a device to produce direct voltage, which is the voltage /signal1. This voltage is subtractedfrom a voltage developed by a known constant voltage in a potentiometer measuring circuit. The subtractionoccurs by connecting two voltages in series with the opposing polarity, difference between these two voltages

produces signal, the voltage going to the amplifier. The error will positive or negative depending on which ofthe two voltages greater. 9hen amplified, the error signal will drive servo balancing motor in appropriatedirection to adHust circuit /actually drive the slide wire1 until the difference between the feedback voltage andthe input voltage is balance out. )n error signal e*ual to 8ero results /null point1 the balancing /servo motoris be longer driven1. What is the co$sta$t ,ota0e $it! 6&2&@.< 63 6c

'r= 6= K &k 'r E


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Materia #or Wes :=. Btainless steel.&. Inconel.-. 3onel.


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Blide wire

Dalancing motor R.T.DIn a balance wheatstone bridge resistance thermometer a resistance bulb is connected into one branch of ad.c. bridge circuitQ in another branch is a variable resistance in the form of a calibrated slidewire. Variations intemp. of the measured medium cause a change in resistance of the bulb and a conse*uent unbalance of thebridge circuit. ) self balancing wheatstone bridge recogni8es the condition of unbalance, determines its

direction and magnitude and position the slidewire contractor to rebalance the bridge and indicate the temp.on the scale.

The 4. '. potential appearing at )) is converted by the converting stage to an ). '. voltage appearing at DDand is multiplied by the voltage amplifier to a large value at cc. It is then used to control the power amplifieroutput 44 which drives the balancing motor in the proper direction to balance the bridge.

The polarity of the signal at )) determines the phase of the alternating voltage at DD which in turndetermines the direction of rotation of the balancing motor.

3. 2o) is ato'atic Re#ere$ce L$ctio$ co'pe$satio$ carrie% ot i$ te'p! Recor%ers!

RheostatK +

Bcale

Variabe Resistor

K +

Re#ere$ce 2ot

$ctio$ L$ctio$*

or automatic reference Hunction compensation a variable nickel resister is used. )s the temperature changes,so does its resistance. This reference Hunction compensatory is located, so that it will be at the temperature ofthe reference Hunction. The reference Hunction is at the position where the dissimilar wire of the thermocoupleis reHoined, which invariably is at the terminal strip of the instrument.

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=%'>" )here: %' F Measre% %ia'eter o# ori#ice.

% F %' 1 ? 9. P %h F Drai$ hoe %ia'eter.%h % F Correcte% %ia'eter ori#ice sie.

44. Epai$ the )ori$0 o# Rota'eter!

OUT +ET

The flow rate varies directlyTapered glass tube as the float rises and falls in

Bcale the tapered tube.

IN +ET

Variable area meters are special form of head meters. 9here in the area of flow restrictor is varied. Bo as tohold the differential pressure constant. The rotameters consists of a vertical tapered tube through which the

metered fluid flows in upward direction. ) "float" either spherical or cone shaped, actually more dense thanthe fluid being measured, creates an annular passage between its maximum circumference and the weight ofthe tapered tube. )s the flow varies the "float" rises or falls to vary the area of the passage so that thedifferential across it Hust balances the gravitational force on the "float" i.e. the differential pressure ismaintained constant. The position of the "float" is the measured of the rate of flow.

47. Epai$ the )ori$0 o# a 'a0$etic 'eter.)n electric potential is developed when a conductor is moved across the magnetic field. In most electricalmachinery the conductor is a "wire"Q the principle is e*ually applicable to a moving, electrically conductiveli*uid. The primary device of commercial magnetic meters consists of a straight cylindrical electricallyinsulated tube with a pair of electrodes nearly flush with the tube wall and located at opposite ends of a tubediameter. ) uniform a.c. magnetic field is provided at right angles to electrode diameter and to the axis of thetube. The a.c. voltage developed at the electrodes is proportional to the volume flow rate of fluid, and to amagnetic field strength. This device is limited to electrically conducting li*uids. The magnetic meter isparticularly suited to measurement of slurries and dirty fluids, since there are no location for solids to collectexcept the walls of the tube itself.

48. Epai$ the )ori$0 o# a trbi$e 'eter.Turbine meters consist of a straight flow tube within which a turbine or fan is free to rotate, about its axiswhich is fixed along the center line of the tube. Btraightening vanes upstream of the turbine minimi8espossible rotational components of fluid flow. In most units a magnetic pick+up system senses the rotation ofthe rotor through the tube wall. The turbine meter is a flow rate device, since the rotor speed is directlyproportional to flow rate. The output is usually in the form of electrical pulses from the magnetic pick+up

with a fre*uency proportional to flow rate. Turbine meter are primarily applied to measurement of clean andnon+corrosive hydrocarbons.

79. Epai$ the )ori$0 o# a *itot tbe.The pitot tube measures the velocity at point in the conduct. If *uantity rate measurement is desired, it mustbe calculated from the ratio of average velocity to the velocity at the point of measurement.*ri$cipe : If a tube is placed with its open and facing into a stream of fluid, then the fluid impinging on theopen end will be brought to rest, and the kinetic energy converted to pressure energy. This the pressure builtup in the tube will be greaterthan that in the free stream by the impact pressure or pressure produced by loss

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of kinetic energy. The increase in pressure will depend upon the s*uare of the velocity of the stream. Thedifference is measured between the pressure in the tube and static pressure of the stream. The static pressureis measured by a tapping in the wall of the main or by a tapping incorporated in the pitot static tube itself.The difference between the pressure in the tube and static pressure will be a measure of the impact pressureand therefore of the velocity of the stream oil.

71. Where is the i$te0ra ori#ice se% !Integral orifice is used to measure small flow rates. It is mounted directly on the secondary device. Theintegral orifice diameter varies between 7.7&7 inch and 7.&;7 inch diameter. The integral orifice finds

considerable use in laboratory and pitot plants.'alculation of flow rate :Q$ B (c F s C)i (a ('


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%n pipe si8es less than & inches corner taps located directly at the face of the orifice plate.

. Ve$a co$tracta a$% ra%is tapsVena contracta taps located at = pipe diameter upstream and at point of minimum pressure downstream.There are mostly widely used for measurement of steam.6adius taps are located = pipe diameter upstream and ^pipe diameter downstream for the inlet face of theorifice are a close approximation to vena contracta taps upto 7.>&d 4./. ( #o) taps:ace flow taps are located at &^ pipe diameter upstream and D pipe diameter downstream. ull flow taps at&^ and D pipe diameter have the same advantage as vena contracta or radius taps.

Ve$tri Tbesor applications where high permanent pressure loss is not tolerable, a venturi tube /igure E1 can be used.

Decause of its gradually curved inlet and outlet cones, almost no permanent pressure drop occurs. Thisdesign also minimi8es wear and plugging by allowing the flow to sweep suspended solids through withoutobstruction.

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(owever a Venturi tube does have disadvantages:

'alculated calibration figures are less accurate than for orifice plates. or greater accuracy, eachindividual Venturi tube has to be flow calibrated by passing known flows through the Venturi andrecording the resulting differential pressures.

The differential pressure generated by a venturi tube is lower than for an orifice plate and, therefore, ahigh sensitivity flow transmitter is needed.

It is more bulky and more expensive.

)s a side noteQ one application of the Venturi tube is the measurement of flow in the primary heat transport

system. Together with the temperature change across these fuel channels, thermal power of the reactor can becalculated.

7. What is Re-$o%s $'ber !4ynamic similarity implies a correspondence of fluid forces in two systems. In general situation there aremany classes of forces that influence the behavior of fluids. Bome of these are inertial viscous, gravitational,compressibility, pressure and elastic forces. 'ertain dimensionless ratio are developed based on fluidproperties. Velocities and dimension, which are essentially force ratio.The more important of these are 6eynolds number

V F ,eocit- , D D F i$si%e %ia'eter o# pipe R F F #i% %e$sit- F ,iscosit-

or most applications in practical flow measurement the 6eynolds number is taken to be sufficient criterion ofdynamic similarly. The magnitude of 6eynolds number not only indicates whether the flow is laminar orturbulent but also furnishes the probable shape of velocity profile. 4ue to the strong role it plays as anindicator of varying flow characteristics, many of the deviation from the theoretical e*uations are called6eynaldo number effects.73. 2o) )o% -o choose %i##ere$tia ra$0e !The most common diff. range for li*uid measurement is 7+=77" (&%. This range is high enough to minimi8ethe errors caused by une*ual heads in the seal chambers, differences in temps. of load lines etc. The =77"

range permits an increase in capacity up to


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film of measured li*uid. The number of cycle of the measuring element is indicated by means of a pointermoving over the dial, a digital totali8er or some other form of register, driven from the measuring elementthrough an adHustable gearing.The 'ost co''o$ #or's o# positi,e %ispace'e$t 'eters are :=. 6eciprocating !iston type.&. 6otating or %scillating !iston type.-. utating 4isc type.. %val 0ear type.77. Wh- are t)o p0s pro,i%e% o$ a D.* tra$s'itter!=.The top plug is a vent plug for venting the air entrapped inside the cell.&.The bottom plug is a drain plug for draining the li*uid accumulated inside the cell.

CONTRO+ VA+VES78. What is a co$tro ,a,es !

) control valve is the final control element, which directly changes the valve of the manipulated variable bychanging the rate of flow of control agent.) control valve consists of an operator and valve body. The operator provides the power to vary the positionof the valve plug inside the body. The plug is connected to the operator by a stem, which slides through astuffing box. The air signal from the controller is applied above the diaphragm. The increasing air signal fromthe controller is applied above the diaphragm. )n increasing air signal will push the operator stem downwardsagainst the force exerted by the spring on the diaphragm plate. The valve is adHusted in such a way that the

plug starts moving when - psi is applied to the diaphragm and touches the seat when =; psi is applied to thediaphragm. Thus an increase in air pressure will close the valve. (ence the home ")ir to 'lose". )nother typeis ")ir to open", such that - psi on the diaphragm the value is closed and =; psi air signal it in fully open.89. What are the %i##ere$t t-pes o# co$tro ,a,es !The commonly used control valves can be divided as follows.=. 4epending on )ction.&. 4epending on the Dody.1. Depe$%i$0 o$ actio$:4epending on action there are two types of control valves, /=1 )ir to close, /&1 )ir to open.". Depe$%i$0 o$ bo%-:=. 0lobe valves single or double seated.

&. )ngle valves.-. Dutterfly valves.


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In double seated valves the upward and downward forces on the plug due to reduction of fluid pressure arenearly e*uali8ed. It is generally used on bigger si8e valves and high pressure systems. )ctuator forcesre*uired are less i.e. ) small si8e actuator.

8. What is C, o# a ,a,e !'v is the capacity of a valve and is defined as :"o of gallons per minute of water which passes through a fully open valve at a pressure drop of = psi. 'V 2 * / _! 0 1

9here: 'v 2 Valve co+efficient * 2 Volumetric flow rate /gallons minute 1 _! 2 !ressure drop across the valve in psi.

0 2 Bpecific gravity of flowing fluid.The valve coefficient 'v is proportional to the area G)G between the plug and valve seat measuredperpendicularly to the direction of flow.

8/. What are the %i##ere$t t-pes o# actators !The different types of actuators are :=. 4iaphragm %perated.&. !iston %perated.

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8. What t-pes o# bo$$ets )o% -o se o# hi0h te'p. a$% ,er- o) te'p. !2i0h te'peratre: Donnets are provided with radiation fins to prevent gland packing from gettingdamaged.O$ ,er- o) te'peratre: Cxtended bonnets are used to prevent gland packing from getting free8ed.

83. 2o) )i -o )or o$ a co$tro ,a,e )hie it is i$e !9hile the control valve is in line or in service, it has to be by passed and secondly the line to be

depressuri8ed and drained.

84. What is the se o# a ,a,e positio$er !The valve positioner is used for following reasons :=. #uick )ction control valve.&. Valve hysteresis.

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-. Valves used on viscous li*uids.. 6eversing valve operation.

87. Whe$ ca$ a b- pass be $ot se% o$ a positio$er !) by pass on a positioner cannot be used when :=. Bplit 6ange operation.

&. 6everse )cting !ositioner.-. Valve bench set not standard.

88. What is the se o# btter#- ,a,es !

Dutterfly valves are used only in systems where a small pressure drop across the valve is allowed. Thebutterfly is fully open when the disc rotates by @7. )%ra)bac o# this valve is that even a very small angulardisplacement produces a big change in flow.

199. What is the se o# three )a- ,a,es !Three way control valves are only used on special systems, where a dividing or mixture of flows according toa controlled ratio is re*uired.

191. What are the %i##ere$t t-pes o# p0s !The different types of plugs are generally used are :/ = 1 V. port plug / & 1 'ontoured plugV@port p0:

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!orted plug are generally used on double seated valves. This is because ported plugs, have a more constantoff balance area.Co$tore% p0:'ontoured plugs are generally used on single seated valve with small trim si8es.

19". What is a ca0e ,a,e !) cage valve uses a piston with piston ring seal attached to the single seated valve "plug". (ere thehydrostatic forces acting on the top or the piston or below the valve plug tend to cancel out. The seat ring isclamped in by a cage. 'age valves are generally used for noise reduction.

19. What are the a%,a$ta0es o# Ca'#e ,a,es !'amflex valves are intermediates between globe valve and butterfly valve. The plug rotates E7G for fullopening.A%,a$ta0es:=. )ctuator forces re*uired are very less.&.Cxtended bonnet and hence can be used on any service i.e. on high temp. and very low Temperature.-. Variations in flow.


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1.+i$ear: The valve opening to flow rate is a linear curve".Ea perce$ta0e: or e*ual increments of valve opening it will give e*ual increment in flow rate range.)t small opening the flow will also be small..Qic ope$i$0: )t small opening the increments in flow rate is more. )t higher opening the flow rate becomes steady.

197. What is a soe$oi% ,a,e ! Where it is se% !

) solenoid is electrically operated valve. It consist of a solenoid / coil 1 in which a magnetic plunger moveswhich is connected to the plug and tends to open or close the value. There are two types of solenoid valves :=. ormally open &. ormally closedUSE : It is used for safety purpose.

198. 2o) )i -o cha$0e the ,a,e characteristics )ith positio$er !The positioner contains different types of came in it. selection of the proper cams in it.Dy selection of theproper cam the valve opening characteristics can be changed.

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119.2o) )i -o cha$0e the actio$ o# a co$tro ,a,e !=. If the control valve is without bottom cap. The actual needs to be changed.&. If bottom cap is provided.a1 4isconnect the stem from the actuator stem.b1 Beparate the body from the bonnet.c1 6emove the bottom cap and the plug from body.d1 4etach the plug from the stem by removing the pin.e1 ix the stem at the other end of the plug and fix the pin back.f1 Turn the body upside down. 'onnect it to the bonnet after inserting the plug and stem.

g1 'onnect back the stem to the actuator stem.h1 ix back the bottom cap.i1 'alibrate the valve.

What is 5e$ch set o# co$tro Va,e!(ow much pressure is re*uired for operate the valve 7 ` =77 $ without any accessories it is called

bench set.

111. 2o) )i -o seect the co$tro ,a,e characteristics !The graphic display of flow various lift shows then the 4esired or inherent characteristic is changed byvariations pressure drop. This occurs as the process changes from condition where most of pressure droptakes place at the control valve is a condition where most of the pressure drop is generally distributedthrough rest of the system.

(o) : This variation in where most of the total drop take place is one of the most important aspects ischoosing the proper valve characteristics for give process.

(o) co$tro :ormally C*ual percentage valve is used.

*ressre Co$tro :ormally linearvalve is used to maintain a constant pressure drop.

Te'p. Co$tro :ormally e*ual percentage valve is used.

+ii% +e,e Co$tro :ormally linear valve is used.

Dasically in selecting a valve characteristic two important point have to be taken into account.a1 There should be a linear relationship between the position of the plug and the flow through the valve in awide range of change in the pressure drop across the valve.b1 The pressure drop across a valve should be as low as possible

Co$tro ,a,e sii$0

11". What is the e##ect o# pipe re%cers o$ ,a,e capacit-!9hen control valves are mounted between pipe reducers, there is a decrease in the actual valve capacity. Thereducers create an additional pressure drop in the system by acting as contractions of enlargements in serieswith the valve.3etric formula: for inlet and outlet reduces.

"

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%" C,"

R F 1 1. 1 @D" 9.9/%"

or outlet reducer only or inlet reducer with entrance angle less than


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TT TIC

Master co$troer Sa,e or Se Co$%ar-

Stea' Co$troer

*T

(ee% )ater (e 0as

*V

'ascade means two controllers is series. %ne of them is the 3aster or !rimary and the second is thesecondary of slave controller. The output of the secondary controller operates the final control element, thatis the valve.+oop epa$atio$:The output of the temp. transmitter goes as measurement signal to the TI' which is themaster controller. Bimilarly the output of pressure transmitter goes as measurement signal to the !I' which isthe secondary controller.The output of TI' comes at set point to !I' which is turn operates the valve. The re*d. temp. is set on theTI'.Use o# casca%e s-ste':'ascade loops are invariably installed to prevent outside disturbances from entering the process. Theconventional single controller as shown in the diagram cannot responds to a change in the fuel gas pressureuntil its effect is felt by the process temp. sensor. In other words an error in the detected temperature has todevelop before corrective action can be taken. The cascade loop in contrast responds immediately correctingfor the effect of pressure change, before it could influence the process temperature. The improvement incontrol *uality due to cascading is a function of relative speeds and time lags. ) slow primary /3aster1variable and a secondary /Blave1 variable which responds *uickly to disturbances represent a desirablecombination for this type of control. If the slave can respond *uickly to fast disturbances then these will notbe allowed to enter the process and thereby will not upset the control of primary /master1 variable. It can be

said that use of cascade control on heat transfer e*uipment contributes to fast recovery from load changes orother disturbances.

114. Epai$ ratio co$tro s-ste'.

U$ co$troe% #o)/ ) 1 (T Ratio co$troer

(1? ("Seco$%ar- co$troer

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/ D 1 (TCo$troe% #o) (V

) ratio control system is characteri8ed by the fact that variations in the secondary variable do not reflect backon the primary variable. In the above diagram 7 a ratio control system the secondary flow is hold in someproportion to a primary uncontrollable flow.If we assume that the output of primary transmitter is ), and the output of the secondary transmitter is D,)nd that multiplication factor of the ratio relay is 5, then for e*uilibrium conditions which means set valve is

e*ual to measured valve, we find the following relation :5) + D 2 7or D) 2 5, where G5G is the ratio setting of the relay.117. Epai$ #e to air ratio co$tro o# #r$aces.

Air (RC Master stea'

(RC (C(T (RC

RS* pri'ar-seco$%ar-

(V RR (T

Ratio co$troer(e 0as

118. What is (r$ace Dra#t co$tro !Dalanced draft boilers are generally used negative furnace pressure. 9hen both forced draft and induced draftare used together, at some point in the systemthepressure will be the same as that of atmosphere. Thereforethe furnace pressure must be negative to prevent hot gas leakage. Cxcessive vacuum in the furnace howeverproduces heat losses through air infiltration. The most desirable condition is that the one have is a very slight

/about 7.=" (&7 1 negative pressure of the top of furnace.

1"9. What is #ee% bac co$tro ! What is #ee% #or)ar% co$tro ! Discss its appicatio$ !(ee% bac co$tro: Co$troer=(IC> Measri$0 ee'e$t Set poi$t Tra$s'itter

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Co$tro ,a,e Ori#ice pateeed back control involves the detection of the controlled variable and counteracting of charges its its valuerelative to set point, by adHustment of a manipulated variable. This mode of control necessities that thedisturbance variable must affect the controlled variable itself before correction can take place. (ence the termGfeedbackG can imply a correction GbackG in terms of time, a correction that should have taken place earlierwhen the disturbance occurred.

(ee% #or)ar% co$tro : Ori#ice

Otpt (T

Co$troer A%%iti,e re0ator

eed forward control system is a system in which corrective action is based on measurement of disturbancesinputs into the process. This mode of control responds to a disturbance such that is instantly compensates forthat error which the disturbance would have otherwise caused in the controlled variable letter in time.eed forward control relies on a prediction. )s can be seen from the figure of feed forward control anecessary amount of input goes to the process. This measurement goes to the controller which gives outputto the control valve. The control valve regulates the flow.

(ee% bac co$tro :

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In feed forward control no difference between the desired result and actual result need exist before correctiveaction is taken in feed back control a difference must exist. (ence, open loop or feed forward control iscapable of perfect control, but feed back is not. 4ue to economic impartibility of precision , predicting theamount of correction necessary to achieve satisfactory results with feed forward control, feed back control ismost often used. In order to properly choose the type of feed back controller for a particular processapplication, two factors time and gain must be considered.

1"1. Epai$ three ee'e$t #ee% )ater co$tro s-ste'!(ee% )ater co$tro Dr' e,e co$tro Stea' co$tro

*" *1 */

Sare root Sare root etractorEtractor *

Co'pti$0 eatio$:*F R = *"@ *1 @ > ? */? 9*F Otpt.*1; *"& */ F I$pt1F A%Lstabe sppressio$.9F A%L.5ias.

1"". Epai$ A$ti@sr0e co$tro! Co'pressor

*DT

*i$et *otet

Ratio

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(T ( (RC= (o) co$,erter>

5-@*ass ,a,eThis method of surge control uses the ratio of compressor pressure rise to inlet flow rate to set the flow inby+bass loop. 9hen the suction pressure drops and discharge shoots up, the compressor starts surging. Thepdt senses this and gives the signal to the 6' which will open the by+pass valve.

What is Sr0e!Burge occurs in a turbo compressor when discharge head cannot be sustained at the available suction flow.Burge occurs at specific combinations of head and flow, as defined by the compressor manufacturerGsperformance curves. %ne or more of the following can result from surge: Fnstable operation !artial or total flow reversal through the compressor 4isrupted process 3echanical damage to the compressor

Sr0e is sa- acco'pa$ie% b- the #oo)i$0: Increase in discharge temperature 6eduction in discharge pressure

Increase in vibration Bharp rise in inlet temperature dependent on the volume flow at the suction.

Avoiding SurgeIn the gas compressor section/igure


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A$s. : Intrinsic safety is a techni*ue for designing electrical e*uipment for safe use in locations madeha8ardous by the presence of flammable gas or vapors in air.

"4efn. :" Intrinsically safe circuit is one in which any spark or thermal effect produce either normally or underspecified fault conditions is incapable of causing ignition of a specified gas or vapor in air mixture at the mosteasily ignited concentration.

2AHARDOUS AREAS :The specification of products or systems sold as intrinsically safe must state in what ha8ardous areas they are

infect intrinsically safe. Fniversal cooling of ha8ardous areas has not, unfortunately, been adopted in allcountries. (owever two sets of codes in common use are.

Qe. : What %oes a tra$s'itter otpt start #ro' @1 psi or =9." @ 1 0BC'"> or / @ "9 'a. etc. !A$s. : The transmitter output stance from what is known as "live 8ero". This system has specificadvantages :=. The systems automatically alarms when the signal system becomes inoperative.&. The output areas is linear / 6atio of = : ; 1.

DEAD HERO SI


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It is any operable arrangement of one or more automatic controllers in closed loops with one or moreprocesses.

SE+( O*ERATED CONTRO++ER :It is one in which all the energy needed to operate the final control element is derived from the controlledmedium through the primary element.

RE+A O*ERATED CONTRO++ER :It is one in which the energy transmitted through the primary element is either supplemented or amplified for

operating the final control element by employing energy from another sources.

*ROCESS :) process comprises the collective function performed in and by the e*uipment in which a variable is to becontrolled.

SE+( RE


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CORRECTIVE ACTION :It is the variation of the manipulated variable produced by the controlling means. The controlling meansoperates the final control element / control value 1 which in turn varies the manipulated variable.

RE(ERENCE IN*UT :It is the reference signal in an automatic controller.

SET *OINT :

It is the position to which the control point setting mechanism is set.

CONTRO+ *OINT :It is the value of the controlled variable which under any fixed set of conditions the automatic controlleroperates to maintain.

D E ( I N A T I O N.

ACCURAC :

) number or *uantity which defines the limit of error under reference conditions.

ATTENUATION :

) decrease in signal magnitude between two points, or between two fre*uencies.

DEAD TIME :

The interval of time between initiation of an impact change or stimulus and the start of the resulting response.

DRI(T :

)s undesired change in output over a period of time, which change is unrelated to input, operatingconditions, or load.

ERROR :

The difference between the indication and the true value of the measured signal.

S*AN ERROR :

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It is the difference between the actual span and the specified span and is expressed as the percent of specifiedspan.

HERO ERROR :

It is the error of device operating under the specified conditions of use when the input is at the lower rangevalue.

STATIC


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It is the general behavior of the output of a device as a function of input both with respect to time.

SI Co$,erter 'onverts an analogue signal /such as a voltage signal from a

temperature sensor1 into a digital signal suitable for input to a computer.

A$ti@Aias (iter )n anti+alias /or anti+aliasing1 filter allows through the lower fre*uency components of asignal but stops higher fre*uencies, in either the signal or noise, from introducing distortion. )nti+alias filtersare specified according to the sampling rate of the system and there must be one filter per input signal.

5acbo$eThe maHor multi+channel link in a network, from which smaller links branch off.

5ac0ro$% NoiseCxtraneous signals that might be confused with the re*uired measurement.

5a% The rate of data transmission in serial data communications, approximately e*ual to one bit persecond.

Chro'e )n alloy of nickel with about =7$ chromium, used with )lumel in 5+type thermocouples.

Co$sta$ta$ )n alloy of


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Di##ere$tia I$pts 6educe noise picked up by the signal leads. or each input signal there are two signalwires. ) third connector allows the signals to be referenced to ground. The measurement is the difference involtage between the two wires: any voltage common to both wires is removed.

Di0ita@to@A$ao0e =DBA> Co$,erter Fsed to produce analogue output signals. These may be controlsignals or synthesised waveforms.

Eectro'oti,e (orce =e'#> 4ifference of potential produced by sources of electrical energy which can beused to drive currents through external circuits. Fnit is the volt.

E$%ra$ce i'it In fatigue testing, the number of cycles which may be withstood without failure at aparticular level of stress.

EIAClectronic Industries )ssociation.

Ether$et ) local area network to which you can connect data ac*uisition devices.

E@T-pe Ther'ocope 'hromel+constantan thermocouple with a temperature rangeof 7+?77 o'.

(I(O b##er) first in, first out, store. The first value placed in the buffer /*ueue1 is the first valuesubse*uently read.

(iteri$0)ttenuates components of a signal that are undesired: reduces noise errors in a signal.

(ree$c-3easured in hert8 /cycles per second1, rate of repetition of changes.

(ree$c- Co$ter'ounts digital pulses over a defined gate time. ) typical gate time is between 7.= and =7seconds.

(ro$t pa$eThe front surface of a unit, generally containing switches and indicator lights.


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Isoatio$ to Earth or S-ste' ) high transient voltage at one input may damage not only the input circuit,but the rest of the data ac*uisition hardware, and, by propagating through the signal conditioning and )4circuits, eventually damage the computer system as well. Pou can prevent this type of damage by isolating theinput from the earth of the data ac*uisition and computer hardware.

Isoatio$ 5et)ee$ I$pts ) transient at an input can also propagate to other e*uipment connected to thatinput. This is prevented by providing isolation between inputs.

@T-pe Ther'ocopeIron+constantan thermocouple with a temperature range of 7 to >;7 o'.

@T-pe Ther'ocope'hromel+)lumel thermocouple with a temperature range of +&77 to =&77 o'.

N@T-pe Ther'ocopeicrosil+isil thermocouple with a temperature range of +&77 to =&77 o'.

Resotio$The resolution of an )4 or 4) converter is the number of steps the range of the converter is

divided into. The resolution is usually expressed as bits /n1 and the number of steps is &n/& to the power n1,so a converter with a =&+bit resolution divides its range into &=&or


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Tra$sie$t) short surge of current or voltage, often occurring before steady+state conditions have becomeestablished.

T@T-pe Ther'ocope'opper+constantan thermocouple with a temperature range of +&77 to


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*RIMAR (EED5AC :It is the signal which is related to the b[tr[(-dj( q3ith thereference input to obtain the actuating signal. Bimply stated primary feedback is the actual measurement ofthe controlled variable which when compared with the desired measurement of the controlled variableproduces the actuating signal.

*OSITIONIN< ACTION :It is that in which there is a predetermined relation between the value of the controlled variable and theposition of the final control element.

*RO*ORTIONA+ ACTION :It is that in which there is a continuous linear relationship between the value of the actual measurement of thecontrolled variable and the value position.

(+OATIN< ACTION :It is that in which there is a predetermined relation between the deviation and speed of final control element.

DERIVATIVE ACTION :It is that in which there is a predetermined relation between a time derivative of the controlled variable andposition of final control element.

REST ACTION :It is the value movement at a speed proportional to the magnitude of deviation.

RATE ACTION :It is that in which there is a continuos linear relation between the rate of change of controlled variable andposition of final control element. 6ate action produces value motion proportional to the rate of change of

actual measurement.*RO*ORTIONA+ 5AND :It is the range of values of the controlled variable which correspond to the full operating range of the finalcontrol element.

RESET RATE :It is the number of timesminute that the effect of proportional position action upon the final control elementis repeated by proportional speed floating action.

There are two ways of expressing reset action :=. 6eset time and &. 6eset 6ate

1. Reset Rate : It is commonly expressed as a number of "repeats" per minute. It is determined by dividing.a1 Travel of final control element / Value stroke 1 in one minute as a result of the effect of proportional speedfloating action.b1 The travel as a result of theeffect of proportional position action with the samedeviation in both cases.

". Reset Ti'e : It is the time interval by which the rate is commonly expressed in minutes. It is determinedby subtracting.

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a1 The time re*uired for a selected motion of the final control element resulting from combined effect of theproportional position plus rate action.b1 The time re*uired for the same motion as a result of the effect of proportional position action alone withthe same rate of change of controlled variable in both cases or expressed in another way. It is the time lead interms of air pressure on the control value produced by rate action compared with proportional position actionfor the same rate of change of actual measurement in both cases.

E + E C T R O N I C S

Qe. : What is a %io%e!A$s. : ) diode consists of two electrodes /=1 )node /&1 'athode. The current flow is only in one direction.) diode is the most basic solid state /semi conductor1 device. The above figure shows a !.. Hunction. The !.material has holes and the . material has electrons.

(ORWARD 5IAS :

REVERSE 5IAS :

/ = 1 9here the applied voltage overcomes the barrier potential /the p side is more positive than the n side1the current produce is large because maHority carriers cross the Hunction in large numbers. This condition iscalled forward bias./ & 1 9hen the applied voltage aids the barrier potential /n side K ve than p side1 the current in small. Thisstate is known as 6everse Dias.

Qe. : What is a ha# )a,e; # )a,e a$% bri%0e recti#ier !A$s. :2A+( WAVE RECTI(IER :

(U++ WAVE RECTI(IER :

5RID


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VO+TA


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Qe. : What are o0ic 0ates ! Epai$ )ith trth tabe.

)ns. :0)TC : ) gate is a logic circuit with one output and one or more inputs . )n output signal occurs only forcontrol combination of input signals.1. OR @


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Ecsi,eOR


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DCS ARC2ITECTURE

Evolution of DCS:

Pneumatic Control System - Single Loop Controllers, More Hardware, Less

Accurate, Cumbersome Maintenance. SLPC - Electronic Controllers, Singlemulti Loop, More Hardware !CS - "ntroduced in t#e $%&s, Microprocessor 'ased, (rap#ic )ser "nter*ace,

"nter*ace +it# t#er !eices, Aailability o* eports / !iagnostics, )ser0riendly.

I/O Block Diagram

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I% Dlock 4iagram

[D 3arshalling6ack

4'B4'B

ield /Hazardous Area1 'ontrol 6oom /Non-HazardousArea1

Transmitters

C/Vsetc.

E7


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*rocess Co$tro @ Co'po$e$ts

2ARDWARE

1ransmitter, Control 2ales etc. Cables, 3unction 'o4. 'arriers, Conerters etc. Power Supply Modules

" Cards / Processor Communication Modules System Communication 'us 5etwor6 (rap#ic !isplay Station 7 C1 perator "nter*ace 7 8eyboard 1ouc#screen Mouse etc.

SOFTWARE DCS

System Con9guration 7 !atabase 'uilder, Control Con9guration Etc. (rap#ic 'uilder

History 'uilder / eport +riter !iagnostic 1ools Logic Editor Control Language 7 )ser Programmable So*tware

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4'B )6'(ITC'TF6C4'B )6'(ITC'TF6C

ieldI%s

3arshalling6ack

I%,!rocessor6ack

DCS COMMUNICATION 5US

IN(ORMATION NETWOR

COMMN.IB(

COMMN.IB(

!' %therBPBTC3B

EN


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E-


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oxboro 4'B

Documents

Important Inst Q & A