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LEVEL MEASUREMENT1.Write the formula for calculating a static head in ka!Static Head = pghp= Density of the liquid

g= Gravityh= height of the liquid column".What are the simle methods for measuring le#el!Gauge glass, Pressure Gauge scale graduated in % of level, Rope and eight ,Dip !ape"etc$.%o& to con#ert a ressure gauge into a le#el gauge!#alculate the static head in $pa using the formula pgh&' Select a pressure gaugeand cali(rate it for the calculated static head' Graduate the pressure gauge scalein terms of %of level''.What is the densit( of crude oil!!he density of crude oil is appro)imately *'+'

).What is an *interface di tae+! Where it used!nterface dip tape is an instrument used for measuring the total and the interfaceliquid level in vessel'-or e)ample. t is used in oil storage tan$s to measure the total liquid level andater level',.E-lain ho& a Le#eltrol &orks! Name the arts of a neumatic Le#eltrol./ 0eveltrol in and instrument used for measuring the liquid level (eteen to$non points' !he 0eveltrol or$s on the (uoyancy principal' 0eveltrol has afloat, hich su(merses proportionately ith liquid level raise in the float cham(er'!he amount of su(mersion of the displacer depends on the liquid density, hichproduces a torque' !he amount of torque produced in measured in terms of % oflevel'Parts of 0eveltrol.-loat cham(er, -loat, !orque lever, 1nife edge, -eed(ac$ 2ellos, /ir Relay,Restriction, -lapper, 3o44le, -eed(ac$ lin$, Density range, /ction change lever,HP and 0P flange,.What is a static head le#el transmitter!/ static head level transmitter is used for measuring the total liquid level in thetan$'/.What are the alication limits of a Le#eltrol and a static head le#eltransmitter!

/ 0eveltrol can measure only for a short and fi)ed height of level' / 0eveltrol hasa high gain output' n can (e used for liquid level as ell for the interface levelmeasurement'Static head transmitter is used for measuring the total liquid level in the tan$' !hetransmitter output is linear'0.What is the oerating rincile of a Magnetrol le#el s&itch!!he 5agnetrol level sitch or$s on the principle of 2uoyancy force'1.What are the oints to consider &hile selecting a le#el s&itch for aarticular rocess!2/8

6hile selecting a level sitch, the folloing points are to (e considered.

- !he characteristic of process 7corrosive or non corrosive8- !he process pressure

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- !he liquid density- !he flange ratings- Proof pressure of the sitch- !he micro sitch contact rating11.What t(e of le#el measuring instrument is suita2le for closed tank!

f the level measurement is required for a fi)ed and small height, a 0eveltrol ismore suita(le'f it is for a total height, then either a static head or a differential pressuretransmitter ith its HP leg connected to the (ottom of the liquid level and the 0Pleg connected to the top of the tan$ to gas phase'1". What is 3ero suression and 3ero ele#ation in le#el measurement!3ero suression4 hen a static head transmitter is installed (elo the 4eroliquid level, the transmitter gets a 9ve error in the level measurement' !his erroris corrected (y a 4ero suppression $it'3ero ele#ation4 hen a static head transmitter is installed a(ove the 4ero liquidlevel, the transmitter gets a ve error in the level measurement' !he error is

corrected (y a 4ero elevation $it'1$. What is an interface in le#el measurement!/n interface is the separation point (eteen the to immisci(le liquids levels n avessel' !his condition arises hen the liquid does not mi) due to its chemicalcomposition and difference in their density'1'.%o& to cali2rate a le#eltrol for an interface le#el measurement!-ill the leveltrol cham(er :**% ith the loer density liquid and ad;ust its 4ero for

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1/. Wh( is a ga controller often used in controlling a le#el in a highressure #essel!Gap controllers output changes from minimum to ma)imum and visa versa henthe process measurement deviates the setpoint (y the set gap' Hence the finalcontrol element i'e' control valve acts li$e an on>off valve' !his helps in

minimi4ing the trim erosion due to a high DP across the control valve hilepartially open'10. %o& to use a 56 7differential ressure8 transmitter for le#elmeasurement!/ differential pressure transmitter gives a linear output for the differentialpressure measured across its HP and 0P cham(ers'#onnect the transmitter?s HP leg to the (ottom of the tan$ and its 0P leg to thetop of the tan$' !he transmitter ill read the liquid level accurately irrespective ofthe change in process pressure a(ove the liquid surface'

9L:W MEASUREMENT

1. What is ;#olumetric< and ;rate of flo&

$. What are the t(es of flo& measurements commonl( used in 56U>A!@rifice plate and a DP transmitter, Daniel @rifice and a DP !ransmitter,Rotameter, PD meters''. What is ;?urnollious Theorem

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' %o& to identif( a ne&l( installed orifice late ustream in a ieline!!he upstream can (e identified (y the orifice plate?s !ag num(er mar$ings' !agnum(ers are alays mar$ed on the upstream of the orifice plate':*' %o& much ustream and do&nstream straight length run is essential foran orifice late flo& measurement!

/n upstream of +D and a don steam of minimum FD is essential for anaccurate orifice plate flo measuring system 7here D= pipeline diameter8'Greater the upstream and donstream length, lesser the flo tur(ulence andgrater the accuracy in the flo measurement'::' What t(e of orifice taing is commonl( used in 6.5.:.!PD@ in general, is using the B-lange !apping?' !he upstream and donstreamorifice tapping are ta$en from the flanges':' Wh( and &hen is flo& measured on a suare root scale!-lo is measured on a square root scale only hen the measurement is donethrough an orifice plate and a DP transmitter' !he flo measured through theorifice plate is alays proportional to the square root of the DP across the orifice

plate'C = $ _ sq root of DP

C = -lo1 = #onstant5/8

DP = Differential Pressure:' What is a ;flo& factor:* squareroot or *>:** linear scale to get the flo calculated (y flo metering' !his is useddue to the standardi4ation of the transmitters signals, to *>:** $Pa or *m/':

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at the operating pressure':F' Wh( is flo& measurement not #er( accurate!-lo measurement is less accurate compared to level, temperature and pressuremeasurement' !his is due to the consideration of various parameters hilemeasuring a flo' !hese parameters, such as the accuracy of the orifice plate

diameter, the pipeline diameter their operating parameters such as temperatureand pressure do not remain same in the process operation as the designedparameters' Generally, an accuracy of % is permitted in a flo measurement':+' What is the actual flo&@ if the oerating ressure is higher then thedesigned ressure!f the operating pressure is higher than the desiged pressure the true flo ill (ehigher then the measured pressure' / simple calculation is as follos'C = C:L sq root of p:MpC = !rue -loC:= 5easured -loP:= @perating pressure

P= Designed Pressure6/8

:' What &ill 2e the ne& flo& factor if a 56 transmitter is re>ranged from ")k6a to ) k6a!/ simple calculation is as follos.C:MC = Sq root of DP:M Sq root of DPC: = C L Sq root of DP:M Sq root of DPC: = 3e flo factor, C =N)isting flo factorDP: = !ransmitter ne range, DP= !ransmitter e)isting rangeC: = CLSC R@@! @- *MC: = :'amplifier magnifies the small signal to a : A D# pea$ to

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pea$ square aves and transmits a signal to the control room'"). What are the ad#antages and disad#antages of a tur2ine meter Vs anorifice late flo& measurement!!ur(ine meter is a good flo measuring unit hen the fluid is lo clean fluid' !hetur(ine meter measures the volumetric flo' t is directly installed on the flo line'

ts accuracy in flo measurement is high' /ccuracy can (e re>calculated and theB$? factor can (e reset periodically'",. What is a ;k< factor on a tur2ine meter! Who ro#ides the ;k< factor!Nach tur(ine meter is specified ith a ?$? factor hich represents the num(er ofpulses produced per a $non quantity of liquid'N)ample. $ = J pulsedMgallonGenerally the B$? factor is provided (y the manufacturer'". :ne cu2ic meter is eual to ho& man( gallons!: #u(ic 5eter = Jt is one and the same' #elsius is the technical name' n simple ords#entigrade is a scale graduated in hundred'). What is a thermo>coule! %o& does it &ork!!o dissimilar metals are elded 7;oined8 at one end to form a Bhot ;unction? andthe other end to form a Bcold ;unction?' 6hen there is a temperature difference(eteen the Bhot? and Bcold? ;unction a mA is produced in the loop proportional tothe temperature difference' !he amount mA production (y a thermo>coupledepends on the characteristic and type of thermocouple li$e B;? , B$? type etc',. What are the measuring ranges of different thermocoule!!he folloing thermocouples measure the temperature accurately ithin thespecified range.

#opper > #onstantan *>** Deg #ron #onstantan *>J** Deg ##hromel > /lumel *>:** Deg #Platinum>Rhodium>Platinum *>*** Deg #. What is the name commonl( used thermocoules in 6.5.:!@n Pump?s (earings. ron constantan@3 Gas !ur(ine?s com(ustion cham(ers. #hromel /lumel/. What is the name of the ca2le used to connect a thermocoule to ameasuring instrument!!he intermediate ca(le used for connecting a thermocouple from the field to thecontrol room instrument is called a Bcompensating ca(le?'

0. What is ;cold Dunction comensation 7CC?8

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a thermocouple' !his compensation is to correct the error caused (y the room7am(ient8 temperature' !he mv produced (y a thermocouple is proportional tothe temperature difference (eteen its Bhot? and B#old? ;unction' !he cold ;unctionis the am(ient temperature 7control room8' 6ithout Bcold ;unction compensation?the temperature at the hot ;unction ill measure inaccurately'

1. What is an RT5! %o& does it &ork!RD! Resistance !emperature Detector8/8

R!D is a positive temperature coefficient resistance hich provides a linear risein its resistance verses the rise in temperature'11. What is the commonl( used RT5 in 6.5.:.!Pt :** platinum resistance :** @hms1". What is ;t 1