LAB # 02 OBJECTIVE: “ TO STUDY THE WORKING OF DEAD WEIGHT PRESSURE.”
(Calibration of a bourdon tube pressure gauge using a dead weight calibration technique).
APPARATUS: HYDRO STATIC BENCH, BOURDEN TUBE GAUGE.
DETAILS OF APPRATUS 1) HYDRO STATIC BENCH
COMPONENTS 1 laboratory trolley 2 switch box, M.NAVEED ZAFAR -055
3 Prandtl tube, 4 measuring cylinder with d=200mm, 5 measuring cylinder with d=100mm, 6 leaf sring manometer, ! sring tube manometer, " mercury #$tube manometer, % tube manometer 2$tube, 10 measuring cylinder d=133mm, 11 ressure sensor with digital dislay, 12 um, 13 suly tan&'
T!"#$!%& D'!($*$+# (xeriments on the toic of the hydrostatics of li)uids and gases can be carried out' * ie section and +arious ressure measuring de+ices are fitted to a laboratory trolley with a demonstration anel, wor&ing area and cabinet' arious measuring containers are integrated into the ie section' -he sealed water circuit and um with suly tan& ermit exeriments to be erformed indeendent of a mains water connection' (xerimental aaratus are included in the cabinet, e'g' a de+ice for determining the centre of ressure of a column of water' -his enables the ressure on a weir to be determined, amongst other asects'
L%(#$# O-!*$/' 0 E($2#*' . /amiliariation
with different methods of measuring ressure . /amiliariations with +arious items of ressure measuring e)uiment . easurement of the static and dynamic ressure comonent in a fluid etermination of the buoyancy of +arious bodies . n+estigations on the density of li)uids . etermination of surface tension . emonstration of caillary effects . emonstration Pascals law
FEATURES losed water circuit M.NAVEED ZAFAR -055
ide range of exeriments
THEORY BOURDEN TUBE GAUGE
t consist of a circular dial and a needle '-he 7ourdon ressure gauge uses the rincile that a flattened tube tends to change to be straightened or larger circular cross$section when ressuried, flattened thin$wall, closed$end tube is connected at the hollow end to a fixed ie containing the fluid ressure to be measured' *s the ressure increases, the closed end mo+es in an arc, and this motion is con+erted into the rotation of a 8segment of a9 gear by a connecting lin& that is usually ad:ustable' * small$diameter inion gear is on the ointer shaft, so the motion is magnified further by the gear ratio' -he ositioning of the indicator card behind the ointer, the initial ointer shaft osition, the lin&age length and initial osition, all ro+ide means to calibrate the ointer to indicate the desired range of ressure for +ariations in the beha+ior of the 7ourdon tube itself' ifferential ressure can be measured by gauges containing two different 7ourdon tubes, with connecting lin&ages'
D%3 4$"* 2%#+2*(: n this aaratus the weights are alied on one end and readings are shown on other end due to the mo+ement of mercury '-his dead weight ressure gauge calibrator consists of a recision machined iston and cylinder assembly mounted on le+eling screws '* 7ourdon gauge is sulied for calibration' -he weights sulied are added to the uer end of the iston rod which is rotated to minimie friction effects' -he gauge is thus sub:ect to &nown ressures which may be comared with the gauge readings and an error cur+e drawn
WORKING PRINCIPLE M.NAVEED ZAFAR -055
A Bourdon gaug u!! a "o#$d %u&' #"' a! #% *+and! du %o +r!!ur #n"ra! "au!! a ro%a%#on o, an ar "onn"%d %o % %u&. #%#n % Bourdon gaug #! a %#n-a$$d %a$ %u&' !oa% ,$a%%nd and &n% #n%o % ,or o, a C. A%%a"d %o #%! ,r nd #! a $/r !!% %a% agn#,#! an o%#on o, % ,r nd o, % %u&. On % ,#*d nd o, % gaug #! a ,#%%#ng ou %rad #n%o a &o#$r !!%. A! +r!!ur #n"ra!! #%#n % &o#$r' #% %ra/$! %roug % %u&. % %a$ %u& &g#n! %o !%ra#g%n a! % +r!!ur #n"ra!! #n!#d o, #%. A! % %u& !%ra#g%n!' % +o#n%r o/! around a d#a$ %a% #nd#"a%! % +r!!ur #n +!#. T Bourdon gaug #! a #g$ a""ura% &u% ra%r d$#"a% #n!%run%
C+#'*(5!*$+# T "on!%ru"%#on o, a &ourdon %u& gaug' "on!%ru"%#on $n%! ar ad o, &ra!!.
PARTS
-he bench to unit contains a 7ourdon tube manometer as the test ob:ect and a iston manometer for generating the test ressure' * +ery recise and reroducible calibration ressure is generated by M.NAVEED ZAFAR -055
loading the calibrated iston with weights' -he &nown ressure is alied to the test manometer' ;ydraulic oil is the medium for transmitting the ressure' -he transarent scale on the manometer allows the sring tube mechanism to be clearly seen'
Learning Objectives / Experiments Princile of oeration of a 7ourdon tube manometer . alibration of a bourdon tube gauge with dead weight gauge' . etermination of the systematic error' .
PROCEDURE OF THE E6PERIMENT 1 2 3 5 6 7 8 :
Ca$"u$a% % d#a and ara o, % +#!%on. S% % a++ara%u!. 4u% % ,$u#d #n % "$#ndr. #" #$$ +a!! %roug % o#! +#+ Ca$"u$a% % #g% o, % +#!%on. 4u% % +#!%on #n % "$#ndr. No % ,$u#d #$$ +a!!! %roug % ou! +#+ %o % Bourdn %u& gaug I% #$$ *r% % !o +r!!ur on % Bourdn %u& gaug. No #% #$$ ,or"d % !%ra#g% u+ % Bourdn %u& d#!%ur&d % $#n9ag. T $#n9ag #$$ ro%a% % ra"9 and +#n#on .#" #! "onn"%d #% % nd$ and % o/n% o, % nd$ g#/! u! % +r!!ur. 10 In"ra! % #g% on % +$ungr and no% % rad#ng %r %o ,our %#.
OBSERVATION AND CALCULATION 1)T 4r!!ur In T F$u#d' In T 4#+ I! Ca$"u$a%d Fro T R$a%#on 4;F
+;#g%
Bourdon tube range 0 to 200 KN/m 2 (KPa)
Area of Piston:
2.45x 104 m2
!ass of "iston:
0.5#g
An$i%%ar& masses:
0.5#g' 1.0#g' 1.5#g '2#g
O-'(/%*$+# %#3 !%&!5&%*$+#:7
M.NAVEED ZAFAR -055
Sr
A&$3
. N
M%''
D%3 4$"* %5
B+5(3+# %5 &+%3 $#!(%'
B+5(3+# %5 &+%3 3!(%'
B+5(3+# %5 %/(% (%3$#
8((+( 9;DW7 BG)0DW<=1>>
o
;?)
-%(
1
0.5
0.2
2 3
1.0 1.5 2.0
0. 0.6 0.8
2. +@ -%( 4%*( 2.0 0.25
.08 6.12 8.2
0. 0.6 0.85
2. +@ -%( 4%*( 2 0.25
.3 6 8.3
0. 0.6 0.8
2. +@ -%( 4%*( 2 0.25
.3 6 8.3
0. 0.6 0.85
2. +@ 4%*( 2
.3 6.03 8.1
20
2. +@ 4%*( 1.:6
0 0 6.25
5.3: 1.7 1.6:
-%(
CONCLUSION T#! dad #g% +r!!ur gaug "a$#&ra%or "on!#!%! o, a +r"#!#on a"#nd +#!%on and "$#ndr a!!&$ oun%d on $/$#ng !"r!. A Bourdon gaug #! !u++$#d ,or "a$#&ra%#on. T #g%! !u++$#d ar addd %o % u++r nd o, % +#!%on rod #" #! ro%a%d %o #n##> ,r#"%#on ,,"%!. T gaug #! %u! !u&?"% %o 9non +r!!ur! #" a & "o+ard #% % gaug rad#ng!. #" g#/ % !a r!u$%. %u! our "a$"u$a%#on #! "orr"%.
M.NAVEED ZAFAR -055
