36778395 Analytical Instruments EI 338

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Two marks Questions & Answers



Unit-I

1· What are the three types of membrane sensor?

Glass sensor

Solid state sensor

Solid matrix sensor

Gas sensin ele!trode &"io!atliti! ele!trodes are merely spe!ial desins that

in!oprate one of the three types#

$· %ow measurements are done in ion sele!tie ele!trodes?

'on sele!tie ele!trodes measure ion a!tiities(ie measures thethermodynami!ally effe!tie free ion !on!entration#'n dilute solutions(ion

a!tiity usually appro!hes ion !on!entration#

)· *efine !ondu!tiity of ele!trolite?

The !ondu!tiity of ele!trolite is a measure of the ability of the solution to !arryele!tri! !urrent#The !urrent throuh the solutin takes pla!e throuh the

moement of ele!tri!ally !hared patrti!les !alled ions#+· ie the methodes of measurin !ondu!tan!e?

,ull methode

*ire!t readin method#

-·Why temperature !ompensation ne!essary in !ondu!tiity measurement?

The !ondu!tiity of ele!trolyti! solution aries with temperation#this is be!ause(

the ioni! mobilites are temperature dependent#the temperature !oeffi!ent is ofthe order of 1#- to $. at room temperature# So !ontrole of temperature is ery

essential #

/· Gie the methodes of measurements of 0xyen?

ethodes used to measure 0xyen are !lassified as either 2hysi!al or 3hemi!almethodes #2hysi!al methode uses the paramaneti! property of 0xyen or

thermal !ondu!tiity as the basis for 4uanditatie determination#3hemi!al

methode in!ludes potentiometri! & !atlyti! !ombustion#5· Gie the workin prin!iple of ele!tri!al !ondu!tiity meter?

The instrument works on the follow in prin!iple (that the !ondu!tiity of an

a4ueous solution depent on the inorani! impurity(& the instrument measures

this in terms of resistense of a std6 water !olumn or tube throuh whi!h thesample is passed#the !ondu!tiity is the re!ipro!al of resistan!e#

7· Gie the appli!ation of Sili!a analyser ?

'n thermal power plants(sili!a !ontent is measured in steam beforeturbine#Sili!a analisers are used ffor anion ex!haner (efluent moniterin &efluents of mixed 8bed ex!haners#

9· What are the two measurements made in Sili!a analiser?

3hemi!al blank measurements

Quanditatie determination

1:· What is !hemi!al blank measurement?



'n this see4uense the ammonia moiybdate solution (sulphuri! a!id&redu!tion

solution are simultaniously added to the mixin essel#This solution is diluted

with sample to a suitable olume & is then empited to the (easurin !uettewhere it is measured & drained away#This is known as !hemi!al blank

measurement#

11· What is the use of blank in sili!a analyser? The reason for the use of blank on ea!h !y!le is to ie the analyser lon term

stability by !ompensatin for the effe!t of ariables su!h as !oloration of the

sample or reaents(temperature(or ain of the lamp of photo !ell#1$· Gie the appli!ation of Sodium analyser?

Sodium analysers find appli!ations in thermal power plants for determinin

sodium ion !on!entration in boiler water ( moniterin !arry oer dete!tion of

!ondenser leakes &the exhaustion of water treatment plant !ation ex!haneunits#

1)· Why ammonia as is added to the sample in Sodium analyser?

The sodium sele!tie lass ele!trode !arries out the measurement in buffered

solution aboe 1:2% ( wher it responds spe!ifi!ially to alue of the sample issodium ion a!tiity # So the 2% must be ad;usted to with in desired rane #The

2% alue of the sample is maintained in the flow !ell by addin ammonia as tothe sample#

1+· %ow 2% of a solution is measured & ie the ,ernst e4uation?

2% is measured by ele!tro !hemi!al !ell ( !onsist of two ele!trodes

easurin <le!trode

=eferen!e <le!trode

easurin ele!trode is sensitie to hydroen ions &=ef6<le!trode is not

sensitie to hydroen ions#The 2% is !al!ulated by ,ernst e4un6 whi!h is ien as

E=E0 +2.303RT/F[PcH]

Where 2!% is the 2% alue deiation from 5#

= is the as !onstant T is the absolute temperature

> is the >aradays !onstant#

1-· Gie the different types of ele!trodes used for 2% measurements?

%ydreen ele!trode

Glass ele!trode

3alamel ele!trode

3ombination ele!trode

1/· Gie the !hara!terists of lass ele!trode?

Sensitiity is aboe 9-.

>aste response

ow meltin point



=elatiely hih ele!tri!al !ondu!tiity

%ih hiros!opi!ity#

15· Gie the desin !riteria of 2% meter?

'nput impedan!e of 2% meter should be ery hih#

3urrent should not be drawn from the solution from the 2% !ell#

Temp6 !ompensation must be proided with resistee thermo meter or

by thermistor#

17· Gie the eneral !lassifi!ation of 2% !ell?

,ull defle!tion type or potentiometri! type#

*ire!t readin type#

19· *ifine humidity &*ew point?

%umidity is the measure of water apour present in a as#'t is usually measuredas absolute humidity(relatie humidityor dew point temperature#

*ew ppoint is the temperature at whi!h saturation of waterapour pressure

is e4ual to the partial pressure of waterapour in the atmosphere#

$:· %ow humidity or moisture is measured &ie the tyoes of it?

=esistie %yrometer

3apasitie %yrometer

i!rowae %yrometer

Aluminiumoxide %yrometer

3rystal %yrometer

Unit II

GAS ANALYSER

1) Define Thermal Conductivity of a gas?

Thermal 3ondu!tiity of a as is defined as the 4uantity of heat

@in !alories transferred in unit time @se!onds in a as between two

surfa!e 1 !m$ in area when the temperature differen!e the surfa!es is

1B3#

2) Why thermistors are used in thermal conductivity analyzer as a heat sensing

elements?



Thermistors possess the adantae of bein extremely sensitie

to relatiely minute !hanes in temperature and hae a hih neatie

temperature !oeffi!ients# The speed of response is also hih#

) What are the appli!ations of thermal !ondu!tiity as analyCer?

a# 't is used in the measurement of hydroen in blast furna!e

ases

b# 'n the determination of aron in 0xyen in the pro!ess of air

de!omposition

!# 'n the determination of sulphur dioxide in roastin ases in

the produ!tion of sulphuri! a!id#

4) How is nitrogendio!ide "re"ared #y chemiluminescence? The nitri! oxide rea!ts with oCone to form nitroenDdiDoxide

with !hemilumines!en!e #

,0 E 0) DDDDF ,0$ E h @liht :#/D )

$) What are the advantages of Hydrogen %ulfide analyzer?

i) 't do not re4uire pumps or aspirators to pull in the sample

ii) They are unaffe!ted by wind or ariations in relatie

humidity#

&)What is the use of gold films in H 2% analyzer?

Gold films absorb hydroen sulfide and reister the !on!entration by a

proportional !hane in their resistan!e#

') Where are the electrochemical sensors used?

<le!tro!hemi!al sensors are preferred in appli!ations where the

atmosphere is oxyen( where ruedness is not important#

() What is the "rinci"le of H2% analyzer?



Sample at a !onstant flow rate enters a humidifier where it

bubbles throuh a -. a!eti! a!id solution# The sample then flows into

the rea!tion window of the sample !hamber( where it passes oer an

exposed surfa!e of paper sensin tape imprenated with lead a!etate#

%$S rea!ts with lead a!etate to form lead sulfide !ausin a brown stain

on the paper# The rate of rea!tion and resultin rate of !olor !hane is

proportional to the !on!entration of %$S in the sample#

)What is the "rinci"le of C* analyzer?

't is based on the oxidation of !arbon monoxide# 't is oxidiCed by

hot mer!uri! oxide#

30 E %0 DDDDF 30$ E %@

The mer!ury apor released may be measured photometri!ally#

1+ ) What is the use of "rotective filter in ,ndustrial analyzer?

'n 'ndustrial analyCer asD handlin !omponents should always

in!lude a small prote!tie filter( pre!eded by a ma;or filter if the as

!ontains suspended matter that re4uires remoal#

11) What is the use of stream drying e-ui"ment?

'f a as sample has a water apour !on!entration hih enouh to

!ause !ondensation within the analyCer( or if moisture is an interferent(

stream dryin e4uipment is ne!essary#

12) What is the need of #y"ass "um"ing devices ?

The bypass pumpin dei!es are needed to keep fresh sample

rapidly supplied to the input of the analyCer#

1.) What are the a""lications of o!ygen analyzer?

i 't is used in the areas of oxyen absorption studies on plants

and tissues #

ii 't is used in food pro!essin industries#



iii 't is also used in respiratory studies#

14) What are the sources of error in o!ygen analyzer?

i The filament temperature is affe!ted by !hanes in the thermal

!ondu!tiity of the !arrier as#

ii The !ross tube must be horiContal to aoid an error due to

raitational !himneyDflow effe!ts#

iii %ydro!arbons and other !ombustible ases in the sample stream

rea!t on the heated filaments !auses !hanes in temperature and

therefore their resistan!e( whi!h results in lare error#

1$) What is the "rinci"le of thermal conductivity analyzer?

't !onsists of a measurin !ell and referen!e !ell# When a aswhose thermal !ondu!tiity is lower is passed throuh the measurin !ell(

then the platinum wires in the measurin !hamber are !ooled less and their

ele!tri!al resistan!e be!omes more# The oltae a!ross the diaonols is

then proportional to the as bein measured#

1&) /!"lain the different analysis methods of 0itrogen *!ide?

i 'nfrared

ii Hltraiolet

iii 3hemilumines!ent

i 3olorimetri!

<le!tro!hemi!al

1') What are the a""lications of /lectrochemical and ,nfrared sensors?

i <le!tro!hemi!al sensors are used for ambient air monitorin

ii 'nfrared sensors are used for sta!k as !on!entration

1() /!"lain the detection methods of Car#on ono!ide nalyzer?

i ,on dispersie method

ii er!ury Iapour

iii 3atalyti! 0xidation

i <le!tro!hemi!al fuel !ell



1) What is necessity of converting nitric o!ide to nitrogendio!ide?

This is be!ause nitri! oxide is essentially transparent in the isible and

ultraiolet reions( it must first be !onerted to ,0$ before it !an be measured#

2+) /!"lain the cali#ration methods used in 0*2 analyzer?

The !alibration methods are *ynami! !alibration & Stati!

!alibration

*ynami! !alibration re4uires preparation of inert as !ontainin

a known !on!entration of ,0$#This may be a!!omplished by as dilution

te!hni4ues#

Stati! !alibration is !arried out with standard solutions of nitrite#

UNIT - III

CHROMATOGRAPHY

1#*efine !hromatoraphy#

3hromatoraphy is defined as the physi!al and !hemi!al method of seperation between arious !omponents of a mixture into pure fra!tions or bands of ea!h

!omponent#

$#what are the different types of as !hromatoraphy?

The different types of as !hromatoraphy are

Gas li4uid !hromatorapry

Gas solid !hromatoraphy#

)#*efine retention time in a !hromatoraphy#

The time re4uired for ea!h of the !omponents to emere from sample ormixture is !alled as the retention time#

tmDtime for unretained !omponentt=1Dretention time of !omponent 1

t=$Dretention time of !omponent $

Amount

0f !omD

ponent



T'<DDDD

+#What are the different parts of as !hromatoraphy? 3arrier as supply with reulators(aues and flow meters

Sample in;e!tion system

3hromatoraphi! !olumn

Thermostat

*ete!tor

=e!order#

-#Gie the seletion !riteria for !arrier as#

The seletion !riteria for !arrier as are

't should be ery !heap

't should hae hih thermal !ondu!tiity 't should be inert

The !arrier as should be sele!ted a!!ordin to the type of

dete!tor used#

/#Write short notes about as !hromatoraphi! !olumn#

The !olumn a!ts as the heartn of a as !hromatoraphy( where the fundamental

pro!ess of seperation takes pla!e#'ts a!tion is based on the fa!t that when a sample of

as or apour is introdu!ed into the !olumn( it spreads by mole!ular diffusion to ie a!on!entration profile#As the sample moes throuh the !olumn( additional spreadin

takes pla!e# "ut (the band maintains the eneral shape( whi!h is dete!ted and re!orded

as a !hromatoraphi! peak#The !hromatoraphi! !olumns are of two types as

2a!ked !olumn

3apillary or 0pen tubular !olumn#

5#What is pyrolysis in as !hromatoraphy ?2yrolysis is an a!!epted method of handlin solid samples# 't extends as

!hromatoraphi! analysis to !ompounds su!h as rubber ( soil( textiles( !oals( resins(

polymers( paint films et!#

The method lends itself to studies on heat stability and thermal de!omposition#'t is also !alled as !ontrolled thermal framentation#

7#ist some dete!tors in as !hromatoraphy #Thermal !ondu!tiity dete!tor

>lame ioniCation dete!tor Thermioni! emmision dete!tor

<le!tron !apture dete!tor

>lame photometer dete!tor



2hoto ioniCation dete!tor

<le!trolyti! !ondu!tion type of dete!tion

*ual dete!tor

9#Gie the prin!iple of GasDSolid !hromatoraphy#

When a as or apour !omes in !onta!t with an adsorbent( !ertain amount of itet adsorbed on the solid surfa!e#this takes pla!e a!!ordin to a phenomenon !alled

anmuir phenomenon ien by JKm L k 1!Ek $!

where k 1(k $!onstants

xmass of as or apour adsorbed

m mass of adsorbent

! apour !on!entration in as phase

1:# #Gie the prin!iple of GasDi4uid !hromatoraphy#

'f the apour or as !omes in !onta!t with a li4uid( a fixed amount of it etsdissoled in the li4uid# This takes pla!e a!!ordin to %enryMslaw of partion ien by

x Km Lk!

where m mass of li4uid used

!apour !on!entration in the as phase

x mass of as

k !onstant #

11#What are the adantaes of as !hromatoraphy?

The adantaes of as !hromatoraphy areGood a!!ura!y and pre!ision

%ih sensitiity Apparatus !ost is !heaper than li4uid !hromatoraphy

Shorter time of analysis

oner life of the instrument#

1$#Write the features of thermal !ondu!tiity dete!tor #

't is simple( inexpensie( nonDsele!tie and non destru!tie and displays a

uniersal respon!e

"ein non destru!tie (the !olumn effulent !an be passed throuh a T3* and

then into a se!ond dete!tor The sensitiity is :#) nKml # The linearty is between 1:+ to 1:-

't is parti!ularly suitable for fra!tion !orre!tion and preparatie as

!hromatoraphy #

1)#0n what fa!tor does the !hoi!e of dete!tor will depend on li4uid !hromatoraphy?

Good sensitiity



"etter sele!tiity

The dete!tor must be able to operate in the presen!e of ba!kround

sinal The response time of the dete!tor must be !ompa!tible with

!hromatoraphy eent #

1+#What are the limitations of bulk property dete!tor?

imitations 6

't is insensitie't re4uires ood temperature !ontrol#

1-#Write the limitations of as !hromatoraphy #0nly about $:. of known !ompounds lend themseles to analysis by as

!hromatoraphy # This is be!ause the !ompounds are olatile and they !annot pass

throuh the !olumn# Also they are thermally unstable and de!ompose under !ertain!onditions of seperation#

1/# What are the different typesof li4uid !hromatoraphy?

The different typesof li4uid !hromatoraphy are i4uidDli4uid !hromatoraphy

i4uidDsolid !hromatoraphy

'on ex!hane !hromatoraphy or "onded phase !hromatoraphy

<x!lusion !hromatoraphy

15#,ame the different types of pumps used for mobileDphase deliery system in li4uid

!hromatoraphy #

The different types of pumps used for mobileDphase deliery system in li4uid!hromatoraphy are

• =e!ipro!atin pump

• Syrine type pump

• 3onstantDpressure pump#

17#What are the different types of !olumns used in li4uid !hromatoraphy ?

The different types of !olumns used in li4uid !hromatoraphy are

Standard !olumn

=adial !ompression !olumn

,arrowDbore !olumn

Short (fast !olumn

Guard !olumns and inDline filters#

19#Write short notes on thin layer !hromatoraphy @T3 #

%ere the stationary adsorbents are applied to a planar lass or a plasti! surfa!e

and the solent is made to flow oer them # All the basi! types of !tions like



adsorption( partition( ion ex!hane and el filtration !an be used on T3 while solents

are applied in a !hamber#

$:#What are the typi!al !olumn appli!ation in li4uid solid !hromatoraphy ?

They are used in plasti!iCers( antioxidants( poly!y!li! aromati!s( orani!

peroxides#

Unit IV

1#State ambertMs law 0= "ouuerMs law#

The mathemati!al statement whi!h states that the radiant power absorbed is

proportional to the thi!kness traersed is !alled the lambertMs law ien by n p:Dln pLln @p:KpLkMb

where p: is the radiant power at xL: and

p represents the radiant power of the transmitted radiation that emeres from the

absorbin medium at xLb and b represents the thi!kness

k is a !onstant#

$#State "eerMs law#

The dependen!e of radiant power on the !on!entration of absorbin spe!ies !an beien by "eerMs law#

n p:KpLkMM3

Where p: is the radiant power at !L: and

p is is the radiant power at !L! and! is the !on!entration of absorbin spe!ies

#

)#State ambertD"eer law#The relation representin

np:KpLkb!

Where p: is the radiant power at distan!e&!on!entrationL:#and2 is the radiant power at distan!eLb&!on!entrationL! and

N is a !onstant is known as ambertO"eer law#

+#State the ma;or pro!ess inoled in AAS# The AAS phenomenon !an be diided into two ma;or pro!ess

1#The produ!tion of free atoms from the sample

$#The absorption of radiation from an external sour!e by these atoms

-#,ame the types of dete!tors used for '= spe!trometry#

1#Thermal dete!tors in whi!h the infrared radiations produ!es a heatin effe!t that alterssome physi!al property of the dete!tors

$#2hoton dete!tors

/#*efine spe!tros!opy#



Spe!tros!opy is the measurement and interpretation of radiation

emitted(s!attered or absorbed by different atoms(mole!ules & other !hemi!al spe!ies

#5# ,ame the different types of spe!trophotometers#

1#HIO isible spe!trophotometers#$#'nfrared spe!trophotometers#

)#>'>= spe!trophotometers#

+#Atomi! absorption spe!trophotometers#-#>lame emission spe!trophotometers

7#What are the liht sour!es used for AAS?

1#%ollow !athode lamp

$#<le!trodeless dis!hare lamp

9#Gie any two appli!ations of flame emission spe!trometry#

1#><S is used in the determination of tra!e metals in li4uid samples#

$#><S finds wide appli!ation in ari!ultural and enironmental analysis(industrialanalysis of ferrous metal and alloy as well as lasses #

1:#Spe!ify the !lssifi!ation of '= reion of spe!trum#

1#photoraphi! reion

$#ery near '= reion@oertone reion)#near '= reion@ibration rotation reion

+#far '= reion@rotation reion

11#,ame the instruments used in '= spe!trometry#1#'= radiation sour!es

$#mono!hromators

)#sample !ells+#dete!tors#

1$#name few '= radiation sour!es#1#in!andes!ent sour!e

$#nernst lower

)#lobar sour!e

+#mer!ury ar!#

1)#Gie the adantaes of ratin mono!hromators

1#ratins !an be made with materials like aluminium whi!h are not affe!ted bymoisture#

$#ratin mono!hromators !an be used oer wide waelenth ranes

1+#Gie + different te!hni4ues used for samplin of solids#

1#solids run in solution

$#solid film te!hni4ues

)#null te!hni4ues



+#pressed pellet te!hni4e

1-#,ame two different types of '= spe!trometers1#dispersie '= spe!trometers

$#nondispersie '= spe!trometers

1/#Gie the adantaes and disadantaes of fourier transform '= spe!trometers#

A*IA,TAG<S6

1#>'>= methods are faster than dispersie instruments and hen!e spe!iallyuseful in situations that re4uire fast repetitie s!annin#

$#>'>= proides in!reased enery throuhput#

*'SA*IA,TAG<S

1#it is expensie than se4uential dispersie instruments$#for the pre!ise moement of the mirror !omputer is also needed#

15#Spe!ify the ma;or desin re4uirements of mono!hromators#

1#simpli!ity$#resolution

)#spe!tral rane+#purity of exitin radiation

-#dispersion

17#,ame the different mountins used in ratin mono!hromators#

1#littrow mountin

$#ebert mountin

)#!CernyOturnermountin

19#,ame the fa!tors on whi!h the radiant power re!eied by a dete!tor depend#

1#number of photons present#$#path lenth of liht

)#!on!entration of the mole!ules absorbin liht

$:#State the prin!iple of operation of flame emission spe!trometry#

'n ><S the sample solution is nebuliCed and introdu!ed into the flame

where it is desolated(apouriCed and atomiCed(all in rapid su!!ession#

Subse4ently(atoms and mole!ules are raised to ex!ited states ia thermal !ollisions withthe !onstituents of the partially burned flames ases#Hpon their return to a lower or

round ele!troni! states the ex!ited atoms and mole!ules emit radiation !hara!teristi! of

the sample !omponents#

UNIT V

1# What is the basi! prin!iple of ,= ?



<lementary parti!les su!h as ele!trons or nu!leus behae as if

rotatess about an axis and thus hae the property of spin # The anular momentum

asso!iated with the spin of parti!le will be an interal or a half interal multiple of h K$P( where h is 2lan!kMs !onstant#

"ased on the property of spin( nu!lei may be diided into three types#

@i 'f the number of neutrons and the number of protons are een( the spin would

be Cero#,u!lei of this type do not ie rise to an ,= sinal(neither do theyinterfere with an ,= sinal from other nu!lei# <xamples 31$(01+#

@ii ,u!lei hain either the number of protons or the number of neutrons as odd

hae halfDinteral spin#<xamples are %1("11(2)1(et!#

@iii ,u!lei whi!h hae both the number of neutrons and the number of protons asodd(would hae interal spin #>or example(%$ and ,1+#

$# *efine ,=? Gie the expresion for the !hemi!al shift#

The study of absorption of radio fre4uen!y radiation by nu!lei in a

maneti! field ia !alled ,u!lear aneti! =sonan!e@,=#

The expression for the !hemi!al shift is

% sample D % TSi 1:/

∧δ L % 1

where % sample and %TSi are the positions of the absorption peaks for the sample

and referen!e mate#

)#Write any three appli!ations of ,= Spe!trometer#

'# Quantitatie analysis 6 The ,= Spe!trometry is used to determine the molar ratio of

!omponents in a mixture#

''# %ydroen "ondin6 %ere the ,< is used to study %ydroen bondin in orani!

!ompounds proton sinal is

shifted towards low field in the !ase of hydroen bondin#

III. Elemental analysis:

%ere ,"= Spe!trometer is used for determination of the total

!on!entration of a ien kind of maneti! nu!leus in the sample#

+#ention the limitations of ,= (Spe!trometer#



1# a!k of Sensitiity#

$# While !hara!tersin the orani! !ompounds( no information about themole!ular weiht is ien( but the relatie number of different protons present

are only known#

)# 'n some !ompounds( two different types of %$ atoms at similar resonan!efre4uen!ies resultin in an oerlap of spe!tra #This makes diffi!ult

interpretation of su!h oerlapped spe!tra#

+# 'n most of the !ases(only li4uids !an be studied by ,= spe!trometry#

-# What are the basi! !omponents of ,= Spe!trometry?

The basi! !omponents of the ,= sp!trometry are6

• A anet(produ!es maneti! field in the rane 1:(::: to $-(::: uass

• =adio fre4uen!y transmittin system#

• The sinal amplifier and dete!tor#• A display dei!e( whi!h may be a re!order or an os!illos!ope#

• A nonDmaneti! sample holder (whi!h holds ths sample#

/# What is ass Spe!trometry?

ass spe!trometry is the most !ommonly used method whi!h

proides 4ualitatie and 4uantatie information about the atomi! and mole!ular!omposition of orani! and inorani! materials#'t produ!es !hared parti!les that

!onsist of the parent ion and ioni! framents of the oriinal mole!ule(and it sorts these

ions a!ordin to their massK!hare ratio#

5# ention the adantaes of ass spe!trometry#

1#"etter Sensitiity# $# ore detailed understandin of kineti!s and me!hanisms of

unimole!ular de!omposition of

mole!ules# )#'mproed Spei!ifi!ity in identifyin unknowns or !onfirmin the

presen!e of suspe!ted

!omponents#

7# What are the arious parts of the ass spe!trometer?

1#Sample inlet system# $#'on sour!e#

)# 'on a!!eleration and ass analyser#

+# 'on !olle!tion system-#*ata handlin system#

/#Ia!!um system#



9# %ow !an we obtain the ,= absorption spe!tra? ,= absorption spe!tra !an be obtained either by !hanin

the fre4auen!y of the =adio fre4uen!y os!illator or by !hanin the spa!ins of the

enery leels by aryin the manti! field#

1:#Sket!h the typi!al ,= Spe!trometer#

>i6"lo!k diaram of a ,= spe!trometer

11# What is the prin!iple behind the G !ounter?



When an ioniCin parti!le enters the !ounter( !ollision with the

fillin as produ!es ion pairs# The formed ion pairs moe towards the appropriateele!trode under the oltae radient# The mobility of ele!tron is hih and under this

potential radient it a!4uires suffi!ient elo!ity to produ!e new ion pairs by !ollision

with atoms of aron# =epeatin of this pro!ess produ!es an aalan!he of ele!tronmoin towards anode# <le!trons when strikin enerates ioniCation throuhout the

tube( !alled dis!hare# <a!h dis!hare builds a !onstant pulse !ounted by s!ale

!ounter# #

1$# What is proportional !ounter?

When the ele!tri! field at the !entre ele!trode of an ioniCation

!hamber is in!reased aboe the saturation leel( but under that of the eier reion( the

siCe of the output pulse from the !hamber starts to in!rease but remains proportional to

the initial ioniCation# A dei!e operated in this prin!iple is !alled a proportional!ounter#

1)# What is depletion reion?

A surfa!e barrier dete!tor !onsists of a pDn ;un!tion formed at the

surfa!e of a sli!e of a sili!on# At the ;un!tion there is a planar reion where there are no

!hare !arriers and no ele!tri! field is !alled depletion reion#

1+# What are the two types of Semi!ondu!tor dete!tors?

1#Surfa!e barrier Sili!on dete!tor#

$#ithium drifted Sili!on and Germanium dete!tors#

1-# What is the dead time in G !ounter ?

When the ele!tron aalan!he is !olle!ted on the anode(the

positie ions( bein mu!h heaier(proress only a short distan!e on their way to!athode## Their time trael is about $::s# *urin most of this time their presen!e as a

irtual sheath around the anode effi!iently lowers the potential radient to a point

where the !ounter is insensitie to the entry of more ioniCin parti!le# This time is!alled dead time of G !ounter#

1/# *efine Absorption (>luores!en!e( *iffra!tion in JDray Spe!trometers?

Absorption of JDrays ies the information about the absorbin

material ;ust as in other reions of the spe!trum#



>luores!en!e emission of JDrays enables to identify and measure

heay elements in the presen!e of ea!h other and in any matrix#

*iffra!tion of JDrays enables analysis of !rystalline materials witha hih deree of spe!ifi!ity and a!!ura!y#

15# What are the basi! instrumentation of JDray spe!trometer

1#JDray eneratin e4uipment

$#3ollimator )#ono!hromator

+#*ete!tor

17# Why do we o for a solid state dete!tor instead of s!intillation dete!tor(et!?

The ele!ri!al output from the solidstate is smaller hen!e a hih ain( low

noise amplifi!ation is re4uired# To diminish noise pi!kup a preamplifier is enerallylo!ated to the dete!tor#Also s!intilation !ounters sufer from poorer enery

resolution#therefore(solid state dete!tors are mostly used#

19# Types of ,u!lear radiation dete!tors6

1#2hoto raphi! <mulsions

$ #'oniCation !hamber

)#The Geier !ounter +#2roportional !ounter

-#S!intilation ounter

/# Semi !ondu!tor dete!tor

$:# Write short notes about the JDray eneratin e4uipment ?

JDrays are enerated in spe!ially desined hih a!!um sealedD

offf tubes(whi!h hae !opper or molybdenum as taret#Tarets are made of tunsten

(iron(!hromium(ni!kel are also sometimes used for spe!ial purposes #*ue to the

bombardment of ele!trons( under the influen!e of the hih oltae( the taret be!omeshot( whi!h !an either rotated or !ooled with !oolin water#

Big Questions

Unit I

1 *es!ribe in detail about the !onstru!tional details and workin prin!iples



of ion sele!tie ele!trodes#

=ef 6 %andbook of Analyti!al 'nstrumentsD=#S# Nhandpur

2ae 6 +/+ 8 +5:

$ What are !ondu!tiity meters? <xplain the prin!iple of !ondu!tiitymeasurement by usin the !ondu!tiity meters in detail#

=ef 6 %andbook of Analyti!al 'nstruments

D=#S# Nhandpur

2ae 6 +$5 8+)1

) *efine p%# What are the desin !riteria of p% meters? <xplain anyone

type of p% meter in detail#


D=#S# Nhandpur

2ae 6 ++7( +-- 8 +-7

+ <xplain with neat diaram a method of measurin oxyen dissoled in

water#


D=#S# Nhandpur

2ae 6 +/+ 8 +5:

- With neat diaram( explain in detail the prin!iple of operation ofsodium analyser#

=ef 6 e!hani!al & 'ndustrial easurementsD=#N#Rain

2ae 6 7+/ 8 7+7

Unit II



1 With neat diaram( explain in detail the workin prin!iple of 0$

Analyser based on maneti! sus!eptibility#


D=#S# Nhandpur

2ae 6 +91 8 +9)

$ *raw & explain the shemati! diaram of a ,0D,0$ analyser#

=ef 6 2ro!ess easurements and Analysis

D"#G#iptak

) With neat diaram( des!ribe the workin prin!iple of a %$S analyser#

=ef 6 2ro!ess easurements and Analysis

D"#G#iptak

+ *raw & explain the s!hemati! representation of the method ofmeasurement of dust !on!entration in sta!k#

=ef 6 e!hani!al & 'ndustrial easurementsD=#N#Rain

- <xplain in detail the prin!iple of workin of thermal !ondu!tiity

analyser with neat diaram#


D=#S# Nhandpur

Unit –III

1 *raw the s!hemati! diaram of a as !hromatoraph & explain the

!omponents#

=ef 6 'nstrumental methods of analysis

Willard( eritt( *ean( Settle

2ae 6 -+: 8 -++

$ *is!uss any two types of dete!tors used in Gas 3hromatoraphy#

@i Thermal !ondu!tiity dete!tor

@ii >lame ioniCation dete!tor





2ae 6 --$ 8 ---

) <xplain in detail the followin dete!tors used in Gas

3hromatoraphy#

@i Thermioni! emission dete!tor

@ii <le!tron !apture dete!tor



2ae 6 --- 8 --5

+ *raw & explain the instrumentation of %23 in detail#



2ae 6 -9$ 8 -9/

- *es!ribe in detail any two types of dete!tors used in i4uid

!hromatoraphy#

=ef 6 'nstrumental methods of analysisWillard( eritt( *ean( Settle

2ae 6 /:: 8 /:5

Unit IV

1 <xplain the sinle beam & double beam instruments used in HI

spe!trophotometer#



2ae 6 1+7 8 1-+

$ *raw & explain the s!hemati! diaram of a typu!al double beam '=spe!trometer#




2ae 6 ):: 8 ):1

) What are nonDdispersie spe!trometers? <xplain in detail the >T'=

spe!trometer# What are the adantaes of the same?



2ae 6 ):1 8 ):-

+*raw & explain the arranement of the ma;or parts of sinle beam &

double beam Atomi! absorption spe!trometer#



2ae 6 $+) 8 $+/

- <xplain with neat diaram about >lame emission spe!trometer#


2ae 6 $+) 8 $+/

Unit –V

1 What is the basi! prin!iple of ,=? *is!uss the workin prin!iple of

,= spe!trophotometer & ie its appli!ations#



2ae 6 +$$( +)1 8 +)5

$ *raw the blo!k diaram of a pulsed >ourier Transform ,=

spe!trometer & explain its workin prin!iple#



2ae 6 +)5 8 +)9

) *es!ribe the workin prin!iple of G !ounter & proportional !ounter



in detail#


2ae 6 )-1 8 )--

+ *raw the blo!k diaram showin the ma;or !omponents of a assspe!trometer & des!ribe#



2ae 6 +// 8 +/7

- <xplain the JD=ay spe!tros!opy in detail#

=ef 6 %andbook of Analyti!al 'nstrumentsD=#S# Nhandpur

2ae 6 )$+ 8 )$9

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36778395 Analytical Instruments EI 338

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