pract 3, levelling - 10, 11,12- final

8/11/2019 Pract 3, Levelling - 10, 11,12- Final

1/10

Surveying Laboratory, Civil Engineering Deptt., CWIT Pune 1.

Pract No. 3A

Date

Time _____am/pm to _____am/pm

Place CWIT, Pune 1.

LEVELING

Object:

Study o Auto !e"el, Compound !e"elin# $ reduction o le"el% &y ri%e $ all met'od.

Instruments:

Auto !e"el, a (m lon# aluminium tele%copic le"elin# %ta.

Theory:

T'e art o determinin# 'ei#'t% or ele"ation% o point% or o&)ect% onr eart'*% %urace +it' re%pectto eac' ot'er or +it' re%pect any accepted point, line or %urace i% called le"elin#.T'e accepted point, line or %urace +it' re%pect to +'ic' t'e "ertical di%tance i. e. 'ei#'t% /dept'% to t'e point are mea%ured i% called a% datum.

In le"elin# to determine ele"ation o point%, t+o in%trument% are reuired "i-. a le"el $ le"elin#%ta. T'e le"el i% a optomec'anical in%trument +'ic' pro"ide% a temporary datum in orm o'ori-ontal line o %i#'t $ le"elin# %ta i% a %caled rod to mea%ure 'o+ muc' point i% a&o"e or&elo+ t'at temporary datum o no+n ele"ation. T'e le"el e%%entially con%i%t% o a le"elin#'ead, a tele%cope $ a &u&&le tu&e. ollo+in# are e+ common type% o le"el% u%ed no+ day%,a0 Dumpy le"el &0 Tiltin# le"el c0 Auto le"el d0 lectronic di#ital% e0 !a%er le"el%

Auto Level:

In ca%e o auto le"el% t'e line o %i#'t i% ept automatically 'ori-ontal e"en t'ou#' t'e &arrel ot'e tele%cope i% tilted +it' in certain tilt ran#e u%ually not e2ceedin# 1*.To maintain t'e line o %i#'t 'ori-ontal an optical de"ice no+n a% 4Tilt Compen%ator* i% itted

+it'in t'e &arrel o t'e tele%cope in t'e line o %i#'t.Auto le"el% can al%o &e itted +it' parallel plate micrometer to read up to t'e raction o mm.5ea%urement% are more a%ter $ preci%e and le%%er ati#uin# +it' Auto le"el%Auto le"el% are itted +it' round &u&&le%. T'o%e can %et uicly.5ea%urin# preci%ion o 1to 6mm per m o dou&le run can &e ac'ie"ed.

Compound Leveling7

Practical Write ups in Surveying for PTD E Civil Page 1


2/10


W'en t'e di%tance &et+een t'e %tation% +'o%e dierence o ele"ation% i% reuired i% #reater t'ant+o time% t'e ran#e o tele%cope $ or +'en t'e dierence o ele"ation &et+een t'em i% to more$ / or +'en t'ere i% no inter"i%i&ility &et+een t'o%e t+o %tation%, t'en +e 'a"e to #o orcompound le"elin#. In compound le"elin# dierence o ele"ation &et+een t+o %tation% i%determined &y compoundin# num&er o %imple le"el% to#et'er.

P $ 8 are t'e %tation% +'o%e dierence o ele"ation i% reuired.CP17 C'an#e point &et+een t'e in%trument %tation% 1 $ 6.CP67 C'an#e point &et+een t'e in%trument %tation% 6 $ 3.9S1, 9S6, 9S3 are &ac %i#'t% rom in%trument %tation 1, 6 $ 3, re%pecti"ely.S1, S6, S3 are ore%i#'t% rom in%trument %tation 1, 6 $ 3 re%pecti"ely.Dierence o ele"ation &et+een P $ 8 : ; : ;1 < ;6 ;3.9ut ;1 : Dierence o ele"ation &et+een P $ CP1 : =9S1 S10 >>>>> ?A% determined &y%imple le"elin# rom in%t. Station 1@;6 : Dierence o ele"ation &et+een CP1 $ CP6 >>>>> ?A% determine &y %imple le"elin# romin% %tation 6@

;3 : Dierence o ele"ation &et+een CP6 $ 8 : =9S3 S30 >>>>> ?A% determine &y %implele"elin# rom in%. Station 3@So Dierence o ele"ation &et+een P $ 8 : ; : =9S1 S10 < =9S6 S60 =9S3 S30

: =9S1 < 9S6 9S30 =S1 < S6 S30; : 9S > S >>>>> Principal o compound le"elin#.Compound le"elin# i% al%o no+n a% dierential le"elin#.INTB5IDIAT SI;T = I. S. 0 7 Any %ta readin# taen rom an in%trument %tation &et+eent'e ore%i#'t and &ac %i#'t %ta readin#% rom t'at in%trument %tation% called a%INTB5IDIAT SI;TE. Durin# compound le"elin# one may tae any num&er ointermediate %i#'t% rom t'at in%trument %tation.C;AN PFINT =C. P.07 It i% a %ta %tation taen in &et+een t+o con%ecuti"e in%trumental

%etup to maintain t'e continuity o +or.



3/10


At e"ery c'an#e point +e 'a"e to tae t+o %ta readin#% "i- a ore%i#'t rom in%trument %tationprecedin# to C.P. and a &ac %i#'t rom in%t. Stn. ollo+in# to C. P. T'e .S. on C. P. i% u%ed toreduce it% ele"ation +.r.t. in%t. A2i% at precedin# in%t. Stn. and 9. S. on C. P. i% u%ed to reducein%t. A2i% at ollo+in# in%t. Station.B.!. F CPn : ;I 1 S1 >>>>>+'ere ;I1 : le"ation o in%t a2i% at precedin# in%t %tn 1.

S1 : ore%i#'t on CPn rom precedin# in%t %tn. 1.le"ation o in%t a2i% at ollo+in# in%t. Stn 6 : ;I6 : B.!. o CPn < 9S6,W'ere 9S6 : 9S on CPn rom ollo+in# in%t. Stn. 6.9ot' S $ 9S at CP alon# +it' ne+ 'ei#'t o in%t. A2i% mu%t &e +ritten in %ame line on a pa#eo le"el ield &oo.

ise And !"ll #ethod o$ Level eduction:

In t'i% met'od B! o a %tn i% ound &y addin# or %u&tractin# t'e ri%e and all re%pecti"ely&et+een t'e %tn and it% precedin# %tn to or rom t'e B! o precedin# %tn.

B! o any %ta %tn. under con%ideration : GB!. o it% immediate precedin# %ta %tn. H Gri%e oall &et+een immediate precedin# %ta %tn, $ t'e %ta %tn. under con%iderationH >>>>>> J%e < %i#nor ri%e $ u%e %i#n or all.Bi%e o all &et+een t'e precedin# %ta %tn. $ t'e %ta %tn. under con%ideration : Di. o %tareadin# taen at t'e immediate precedin# %ta %tn and t'e %ta readin# taen at %ta %tn. undercon%ideration. I t'i% dierence o %ta readin#% i% po%iti"e t'en t'ere i% ri%e rom t'e immediateprecedin# %tn to t'e %tn. under con%ideration $ I t'i% dierence o %ta readin#% i% ne#ati"et'en t'ere i% all rom t'e immediate precedin# %tn to t'e %tn. under con%ideration.

A% t'e %ta readin# '8E at ollo+in# %ta %tn 8 K %ta readin# 'PE at precedin# %ta %tn. P ora% %u&traction ='P > '80 o t'e %ta readin# at P $ 8 i% ne#ati"e, t'ere i% 4all : ='P > '80* in&et+een t'e precedin# %ta %tn. P and t'e ollo+in# %ta %tn 8. T'u% B! o %ta %t. 8 : =B! o%ta %tn. P all rom %ta %tn. P to %ta %tn. 80

A% t'e %ta readin# '9E at t'e allin# %ta %tn. 9 L t'en %ta 'AE at t'e precedin# %tn. A or a%%u&traction ='A>'90 o t'e %ta readin# at A $ 9 i% po%iti"e, t'ere i% 4Bi%e : ='A > '90* &et+een



4/10


t'e precedin# and ollo+in# %ta %tn%. A $ 9. T'u% B!. o %ta %tn. 9 : =B! o %ta %tn. A < ri%erom %ta %tn. A to %ta %tn. 90.

Arit'metical c'ec% or ri%e and all met'od

=9S > S0 : =Bi%e > all0 : =!a%t B! ir%t B!0

eature% o ri%e and all met'od710 T'ere i% complete c'ec includin# eac' o intermediate %ite =IS060 Sy%tem i% little tediou%, %lo+ and in"ol"e% more calculation%.30 J%ed +'en +or in"ol"e% more no o intermediate %ite a% in ca%e o proile

le"elin#, cro%% %ectionin#, &loc contourin#, etc.

Note: In le"elin#, %tn mean% %ta %tn mean% a point +'ere t'e %ta i% 'eld and not a point +'eret'e in%trument i% %tandin#I ri%e and all are recorded %eparately in t+o %eparate column% on a pa#e o le"eled ield&oo, no need o enterin# t'e all% t'ere +it' ne#ati"e %i#n.

e$erence:

or ta&ulated o&%er"ation% o dou&le c'ec le"elin# $ or clo%in# error calculation, reer pa#eno%. 9 ______________________

Pract No. 39

Date

Time _____am/pm to _____am/pm

Place CWIT, Pune 1.

LEVELING

Object:

Study o !a%er !e"el, ly !e"elin# $ reduction o le"el% &y collimation plane met'od.

Practical Write ups in Surveying for PTD E Civil Page (


5/10


Instruments:

!a%er le"el =Bu#&y 1MM0 +it' it% %tand , la%er detector =rod eye mini 0, (m aluminum %ta.

L"ser Level:

A la%er le"el i% recent, ea%y to under%tand and %imple to u%e ind o a le"el. It con%i%t% o arotatin# la%er la%'er =3nm, "i%i&le, cla%% II D, Cla%% 6 IC0 mounted on %el ali#nin#

"ertical a2i%. W'en %+itc'ed on it pro"ide% "i%i&le plane o collimation ormed &y a 'ori-ontalla%er &eam rotatin# t'rou#' 3MO continuou%ly.

i#7 Component Part% o Bu#&y 1MM !a%er !e"el

T'e main ad"anta#e o la%er le"el% i% t'at it %a"e% time o le"elin# con%idera&ly on account o it%#reater operatin# ran#e o 3MMm, +'ic' i% almo%t t'ree time% t'at o t'e con"entional opticalle"el% and it% %el le"elin# accuracy o 6. mm at 3M meter%. It i% more %uita&le or le"elin# o+ide %pread area lie a play #round, indu%trial loor, etc.W'ile le"elin# +it' a la%er le"el +e reuire% a la%er le"el proper =%uc' a% Bu#&y 1MM0 and a la%er&eam detector =%uc' a% Bod ye 5ini0

T'e Control Panel o Bu#&y 1MM !a%er !e"el

T'e control panel o Bu#&y 1MM con%i%t o an o/on po+er &utton, an automatic/manual &utton, apair o manual #rade &utton =+it' up/do+n arro+ mar%0 and 3 !D indicator% =1 yello+ and 6red0.

i#7 Control Panel o Bu#&y 1MM

9utton% F/FnPo+er

Turn% t'e unit on $ o $ c'an#e% t'e 'ead %peed%. Pre%% t'i% &utton onceto turn on t'e in%trument at rp%. Pre%%in# t'i% &utton %econd timeincrea%e% t'e 'ead %peed to 1M rp%. Pre%%in# t'i% &utton t'ird time turn%t'e in%trument o.

Practical Write ups in Surveying for PTD E Civil Page

Botatin# !a%er la%'er

Control Panel

;andle

C'ar#e )ac

!D !D !D

F/Fn Po+er 9utton

Automatic/5anual 9utton

5anual rade 9utton


6/10


Automatic/5anual

S+itc'e% t'e unit &et+een automatic %el le"elin# mode $ manual mode.T'e manual mode indicator !ed +ill la%' +'en in t'i% mode.

5anual

rade

Fr

T'i% %et o t+o red &utton% control% t'e tilt o main a2i% +'en t'ein%trument i% in manual mode. In manual mode t'e arro+ &utton% allo+

t'e operator to tilt t'e la%'er 'ead to matc' an e2i%tin# line or %lope =upto 1M0. W'en acin# t'e control panel $ t'e up arro+ i% pre%%ed, t'eplane o la%er +ill tilt up+ard% a% it mo"e% a+ay rom t'e operator.Pre%%in# t'e arro+ &utton +ill mo"e t'e 'ead in %mall increment%.Pre%%in# $ 'oldin# t'e &utton mo"e t'e 'ead more uicly.

!D%

1

!a%er mi%%ion Indicator =Qello+0F7 T'e in%trument i% %+itc'ed ola%'in#7 In%trument i% #ettin# it%el le"elledFn7 In%trument i% le"eled $ t'e la%er &eam i% on

6

!o+ &attery indicator =Bed0F7 9attery FRSlo+ la%'in# =1;-07 !o+ &atterya%t la%'in# = ;-07 ery lo+ &atteryFn7 ery "ery lo+ &attery, in%trument +ill turn o in minute%.

35anual 5ode Indicator =Bed0F7 In%trument i% automatic %el le"elin# modela%'in#7 In%trument i% in manual mode

Ft'er Important eature% F Bu#&y 1MM !a%er !e"el"% le"ation Alert =;.I.0 Indication7W'en acti"ated +ill reduce t'e amount o %el le"elin# ran#e to pre"ent ele"ation error% a% are%ult o mo"ement o t'e tripod or ot'er %udden mo"ement. T'e ;. I. alert unction #et%automatically turned on +'en t'e Bu#&y 1MM i% %+itc'ed on. All t'ree !D*% la%'e% t+ice toindicate t'at t'e automatic ;.I. Alert unction i% ena&led. T'irty %econd% ater t'e Bu#&y 'a%le"eled, t'e ;.I. Alert unction +ill &ecome acti"e. All t'ree !D*% la%'e% once to indicate t'att'e unction 'a% &een acti"ated. I t'e Bu#&y i% di%tur&ed and an ;.I. Alert unction i% acti"e, allt'ree !D indicator% +ill la%' %imultaneou%ly =;-0. Po+er o t'e unit to %top t'e ;.I Alert.C'ec% t'e cau%e o t'e alert, i reuired re>le"el t'e tripod %tand 'ead. Po+er on t'e unit a#ainallo+ t'e in%trument rele"el $ la%er la%'er to on $ continue +it' le"el operation. To di%a&le t'e;. I. Alert unction, pre%% $ 'old &ot' t'e Jp $ do+n arro+ &utton%, t'en pre%% $ relea%e t'eAuto/5anual &utton. All t'ree !D*% +ill la%' t+ice to indicate t'at t'e ;. I. unction 'a% &eenena&led or di%a&led. T'e in%trument mu%t &e in automatic mode to ena&le/di%a&le t'e ;.I. Alertunction.

b% Fut o !e"el Indication7W'en t'ere i% an out o le"el ailure, t'e in%trument 'a% &een %et up out%ide o it% %el le"elin#ran#e = O in ca%e o Bu#&y 1MM0 and can not ac'ie"e le"el. T'e all t'ree !D +ill &lin in%euence. Turn unit o, le"el t'e tripod %tand 'ead. Po+er on t'e unit a#ain allo+ t'e in%trumentre>le"el $ la%er la%'er to on $ continue +it' le"el operation.

c% Fut o Temperature Ban#e7



7/10


I t'e in%trument i% %+itc'ed on and en"ironmental temperature i% out o t'e %peciied operatin#temperature ran#e =>6MO to MO C0, all t'ree !D*% +ill turn on at %ame time.

Po+er Source o Bu#&y 1MM !a%er !e"el7T'e Bu#&y 1MM i% po+ered &y a Ni5; rec'ar#ea&le &attery pac. T'i% pac it% in to t'e &ottomo t'e Bu#&y 1MM only in one direction. ully c'ar#ed Bu#&y 1MM +ill +or or more t'an 3

'our% in optimal condition%. T'i% &attery pac can &e c'ar#ed +it' 'elp o a uni"er%al c'ar#er%upplied +it' Bu#&y 1MM. To c'ar#e t'e &attery pac, +it' &attery pac in it% place, in%ert t'eplu# in to t'e c'ar#e )ac located &elo+ t'e control panel o Bu#&y 1MM $ t'e AC adopter in toappropriate electrical outlet on +all. 9attery pac can al%o &e %eparately c'ar#ed &y remo"in#a+ay rom Bu#&y 1MM.

Worin# +it' !a%er !e"el7a0 Automatic Fperation1. Set up t'e Bu#&y 1MM on a nearly le"eled tripod 'ead or lat le"el %urace,6. Pre%% t'e o/on po+er &utton once to turn on la%er la%'er at rp% or t+ice at 1M rp%,3. T'e Bu#&y 1MM +ill le"el it%el la%'er +ill %+itc' on and +ill t'en &e#in to rotate.(. Automatic ;.I. Alert +ill &ecome acti"e ater 3M %econd%.. No+ +or can &e#in &y readin# on le"elin# %ta +it' 'elp o la%er &eam detector.

&0 5anual Fperation1. Set up t'e Bu#&y 1MM on a nearly le"eled tripod 'ead or lat le"el %urace,6. Pre%% t'e o/on po+er &utton once to turn on la%er at rp% or t+ice at 1M rp%,3. Pre%% t'e Automatic/5anual &utton once to operate t'e Bu#&y in manual mode.(. o on pre%%in# t'e 5anual rade &utton =U or V0 to tilt t'e la%'er 'ead to matc' %lope la%er

plane to t'e )o&%ite reuirement.. No+ +or can &e#in &y readin# on le"elin# %ta +it' 'elp o la%er &eam detector.

!a%er 9eam Detector =Bod ye 5ini07T'e Bod ye mini i% a la%er detector de%i#ned to operate +it' rotatin# la%er%, to detect and

indicate t'e po%ition o t'e o t'e la%er &eam. It i% de%i#ned or #eneral con%truction application%.It 'a% &ot' an !D indication on t'e ront panel t'at #i"e% t'e operator a "i%ual indication, a%+ell a% an audio indicator t'at emit% t'ree di%tinct audio tone% or 'i#', lo+ and on #rade. T'i%model al%o 'a% a ma#net &uilt in to t'e top o t'e 'ou%in# to allo+ t'e %en%or to &e ea%ilyattac'ed to ceilin# #rid.

i#7 ront ie+ T'e Bod ye 5ini !a%er Detector


I

II

III

I


8/10


I Po+er 9uttonTurn% t'e detector on and o and i% al%o u%ed to %elect t'e audio le"elo t'e &eepin# %ound. Pre%% $ 'old t'e %+itc' or appro2imately t+o%econd% to turn o t'e detector

II Audio Speaer a%t &eep detector unit too 'i#',Solid tone detector unit on #rade,

Slo+ &eep detector unit too lo+.

III!a%er

BeceptionWindo+

T'e %et o p'oto cell% located &e'ind t'i% +indo+ detect% t'e la%er&eam. T'i% +indo+ mu%t &e directed to+ard% t'e la%er le"el $ %'allnot &e co"ered any +ay +'ile t'e detector i% in u%e.

I !D Di%playT'i% di%play indicate% t'e po%ition o t'e %en%or relati"e to t'e la%er&eam comin# rom t'e la%er le"el.

T'e !D Di%play o Bod ye 5ini !a%er Detector

1 Bed !DIndicate detector i% little a&o"e la%erplane o collimation $ need% to &emo"ed do+n+ard%.

6 reen !D Indicate detector i% in line +it' la%r planeo collimation.

3 Am&er !i#'t !o+ &attery indication.

( Bed !i#'tIndicate detector i% little &elo+ t'e la%erplane o collimation $need% to &emo"ed up+ard%.

Worin# +it' Bod ye 5ini !a%er Detector1. Turn &ac t'e detector. Fpen t'e door o t'e +aterti#'t &attery compartment +it' a coin.

Place t+o ne+ alaline AA &atterie% in t'e po%ition a% %'o+n on t'e dia#ram pa%ted in t'e&attery compartment.

6. Pre%% t'e po+er &utton once to turn on t'e detector. T'e &eeper +ill %ound $ t'e !D*% +illla%'. T'e centre #reen !ed +ill continue to la%' %lo+ly, indicatin# t'at t'e detector i% turnedon.

3. Pre%%in# t'e po+er &utton a#ain +ill to##le t'e %en%or t'rou#' t'e audio "olume% =;i#', lo+$ o0. Pre%%in# $ 'oldin# t'e po+er &utton or t+o %econd% +ill turn t'e detector o. T'edetector automatically turn% o ater 3M minute% on non u%e.

(. T'e am&er colored lo+ &attery !ed indicator +ill appear +'en t'ere i% appro2imately one'our o lie let in t'e &attery.

Practical Write ups in Surveying for PTD E Civil Page X


9/10


i#7 !a%er !e"el in J%e

. To record t'e %ta readin#. ;old t'e detector alon# %ide>ace o t'e le"elin# %ta, +it' ronto t'e %en%or to+ard% t'e la%er le"el. W'en t'e p'otocell% are acti"ated &y t'e la%er, t'e !D$ audio +ill immediately &e#in indicatin# t'e po%ition o t'e &eam. 5o"e t'e detector"ertically, a% #uided &y t'e detector it%el, on %ide>ace o t'e %ta till it come% on t'e #rade $central #reen !D i% illuminated.

. Bead t'e le"elin# %ta a#ain%t t'e marin# made a#ain%t t'e central #reen !D on detectorand #et it recorded in appropriate in column o le"el ield &oo a% u%ual.

Observ"tion T"ble

StaStation

Sta Beadin#% Collimation PlaneB. !. Bemar%

9S IS S Bi%e all163(XY1M

9S : __________S : __________9S > S : __________

Bi%e : ___________all : ___________Bi%e > all : ___________

!a%t B! : ___________ir%t B! : ___________!B! > B! : ___________

A% = 9S > S 0 : = Bi%e > all 0 : =!B! B!0, Calculation% are FR!ly Leveling:

In order to )ud#e t'e error in le"elin# +or. It i% reuired to clo%e &ac t'e le"elin# +or a#ainon %ame point rom +'ic' it +a% %tarted. T'e proce%% o carryin# t'e le"el% rom clo%in# %ta%tation to t'e %ta %tation rom +'ic' t'e le"elin# +or i% %tarted id called a% !Q !!INFB C;CR !!IN.E ly le"elin# i% a compound le"elin# or dierential le"elin#, &utpreera&ly no intermediate %i#'t% are taen durin# ly le"elin#.?Actual error o ? le"ation o %ta %tn. or ?le"ation o %ta %tn.orClo%ure in le"elin# +or@ : 9. 5. at clo%e o +or.@ > 9.5. at %tart o +or.@

Practical Write ups in Surveying for PTD E Civil Page Y


10/10


Permi%%i&le error o clo%ure 7 > =CZR0 mm. W'ere R : Di%tance tra"eled to and ro in m AndC i% a con%tant and : Y or rou#' le"elin#, 6( or ordinary le"elin#, 16 or accurate le"elin#. $ or preci%e le"elin#.or %ati%actory le"elin# +or, actual error o clo%ure %'all &e le%% t'an eual to permi%%i&le error

clo%ure.eduction o$ Levels &y '(eight o$ Instrument )(*I*%+ or 'Collim"tion ,l"ne+ #ethod:

T'ere are t+o %y%tem% o le"el reduction "i-.10 Collimation plane or ;ei#'t o in%trument =;.I.0 met'od $60 Bi%e $ all met'od.Collimation plane or 'ei#'t o in%trument = ;. I. 0 met'od 7> T'i% met'od con%i%t o indin# t'eele"ation o t'e collimation plane =i.e. ;.I.0 or e"ery %etup o in%trument and t'en o&tainin# t'eB. I. o point% +.r.t. t'e re%pecti"e plane o collimation.

? le"ation o collimation : 9S on 95 or CP B.!. o t'at 95 or CPplane Fr ;.I. at any in%t. rom t'at %etup. < on +'ic' t'e 9S i% taen.Setup@

?B.!. o a %tn rom any %etup : ;.I. at t'at in%t. %etup Sta readin# at t'ato t'e in%trument@ < %ta %tation.

Arit'metical c'ec or 'ei#'t o in%trument =;.I.0 or collimation plane met'od 9S > S : !a%t B.!. ir%t B.!.E.

eature% o ;ei#'t o in%trument or collimation plane met'od.10 !e%% tediou%, more rapid $ in"ol"e% le%% calculation%.60 5i%tae% made in reduction o le"el% o Intermediate Si#'t% =i.e. I.S.0 remain undetected.30 J%ed +'en +or in"ol"e% le%% num&er% o or no intermediate %i#'t% a% in ca%e o ly orc'ec le"elin#.

Note7 In ca%e o t'e point a&o"e t'e line% o collimation, %uc' a% &ottom o c'a))a or %la& or %oito &eam etc. Sta readin# i% taen on t'em &y 'oldin# t'e %ta in"erted a#ain%t t'em.Suc' %ta readin#% are to &e recorded +it' ne#ati"e %i#n in ield &oo.

______________________________________________________________________________e$erence:

or ta&ulated o&%er"ation% o compound le"elin# and ly le"elin# and or clo%in# errorcalculation%, reer pa#e no%. 9___________

Practical Write ups in Surveying for PTD E Civil Page 1M

pract 3, levelling - 10, 11,12- final

Documents