emda lab report 1

7/21/2019 EMDA Lab Report 1

http://slidepdf.com/reader/full/emda-lab-report-1 1/16

Static calibration of bridge and voltage divider circuits forTemperature Measurement

Venkata Rohith Reddy Matli

Group member: Arpit Thyagi

Date: September 9th, 20!"

#age $%



Introduction

Theory

&ne o' the mo(t important part( o' thi( e)periment i( *heat(tone bridge" A *heat(tone bridge i(

an ele+tri+al +ir+uit u(ed to mea(ure an unkno*n ele+tri+al re(i(tan+e by balan+ing t*o leg( o' a

bridge +ir+uit, one leg o' *hi+h in+lude( the unkno*n +omponent" &ne o' the adantage( o' u(ing

a *heat(tone bridge *hen +ompared to a oltage diider +on'iguration i( the a++ura+y a((o+iated

*ith the re(ult(" The re(ult( obtained 'rom *heat(tone bridge +on'iguration are more a++urate*hen +ompared to tho(e obtained 'rom oltage diider"

Motivation/Objective

Thermi(tor( are ery ine)pen(ie, highly (en(itie temperature mea(urement dei+e(" Thi(

e)periment *a( done in order to determine the a++ura+y o' the alue( mea(ured by thermi(tor by

+omparing it *ith a true alue o' temperature *hi+h i( mea(ured a+ro(( a TM# -% (en(or" The

e)periment *a( +ondu+ted by +onne+ting the thermi(tor in t*o di''erent tran(du+er

+on'iguration( in order to ob(ere the di''eren+e in alue( obtained" The(e alue( *ere then

+ompared to determine the relatie a++ura+y o' the tran(du+er (y(tem( u(ed and to determine the

ne+e((ity to +alibrate thermi(tor"

MethodsA .heat(tone bridge *a( (etup on the breadboard in the +on'iguration (ho*n in /ig" u(ing the

'i)ed re(i(tor(, potentiometer and a thermi(tor" The bridge output *a( +onne+ted to the +hannel(

indi+ated in /igure on the bla+k terminal board atta+hed to the ab1a+k u(ing 1umper +able("

Analog input +hannel( that *ere ne)t to ea+h other *ere u(ed to mea(ure di''erential3 potential in

the +ir+uit" TM# -% (en(or i( al(o +onne+ted to the ab1a+k" A "4T 'ile that log( the data 'romTM# -% (en(or and .heat(tone bridge i( +reated in DA5 'a+tory" .heat(tone bridge i( balan+ed

at room temperature" The re(i(tan+e( o' all the +omponent( in the +ir+uit are determined u(ing

multimeter"

TM# -% and thermi(tor are put in hot *ater +olle+ted in a tumbler" The alue read by TM# -%

(en(or i( monitored and on+e the temperature (tabili6e( aboe 70 degree( +entigrade the oltage

alue( a+ro(( the .heat(tone bridge are logged in the "+tl 'ile +reated be'ore" 8+e i( added (tep by

(tep to redu+e the temperature o' *ater in the tumbler and alue( are logged eery time the

temperature (tabili6e(" Thi( i( +ontinued till the *ater in tumbler rea+he( a temperature o' 7degree( +entigrade"

The (ame pro+edure i( repeated 'or a oltage diider +on'iguration"

The de(ign (tage un+ertainty in temperature alue( mea(ured a+ro(( the thermi(tor *a(

determined by +ondu+ting un+ertainty analy(i( u(ing the un+ertainty a((o+iated *ith the ariou(

+omponent( u(ed in the *heatone bridge +ir+uit"

#age 2$%



Figure 1 (adapted from MTU lab materials): Schematic of thermistor/wheatstone bridgeand temperature sensor configuration for simultaneous measurement and calibration

Results/Discussion

Results obtained across the wheatstone bridge

The oltage de'le+tion a+ro(( the *heat(tone bridge and the temperature mea(ured by the TM# -%

are tabulated" (ing the oltage di''eren+e a+ro(( the *heat(tone bridge and the kno*n alue( o'

the 'i)ed re(i(tan+e( and potentiometer3( re(i(tan+e the arying re(i(tan+e o' the thermi(tor

+orre(ponding to ea+h temperature i( +al+ulated" The temperature mea(ured by the thermi(tor at

ea+h point i( determined u(ing the 'ormula "

Formula 1 (adapted from Visha 1!" data sheet): #esistance to absolute temperature$

Table 1: Values obtained from wheatstone bridge$

ThermistorBridge (V)

Temperature

TMP36 (C)

Resistance(ohm)

T(C) Absolute

ΔT

0.9829941 45.70187 4364.336381

45.046

75

0.655120

408

0.9819932 45.68847 4368.463108

45.022

56

0.665906

93

0.6989037 39.34025 5639.474632

38.603

34

0.736912

731

0.6991007 39.23382 5638.511799

38.607

55

0.626266

84

0.1583554 28.84504 8819.872579 27.892 0.952132

#age -$%



91 38

0.1570471 28.77014 8829.143098

27.868

5

0.901635

154

-0.70894 12.73955 17945.76201

12.140

3

0.599251

658

-0.7156178 12.60789 18050.54585

12.017

09

0.590801

572

-1.020115 6.905376 23836.82076

6.2370

52

0.668324

022

-1.025192 6.905376 23953.62229

6.1372

38

0.768137

968

0.9919397 46.18201 4327.558746

45.263

46

0.918548

903

0.9874393 46.14022 4346.037415

45.154

31

0.985905

754

&n +omparing the alue( mea(ured by the TM# -% (en(or and thermi(tor an ab(olute error o' 0"degree( +entigrade i( ob(ered" A( per the data (heet o' TM# -% (en(or it ha( an a++ura+y o' ; 2

degree( +entigrade" There'ore, the alue( obtained u(ing TM# -% (en(or and thermi(tor (en(or

'all *ithin the (ame range" A( there i( no (y(temati+ error <la+k o' o''(et= a((o+iated *ith the

alue( mea(ured a+ro(( the thermi(tor *hi+h +an be noti+ed 'rom the graph in /igure 2 the errorthat *e noti+ed in the alue( mea(ured +an be attributed to random error <hy(tere(i(, linearity

et+"="

Figure % & Voltage across wheatstone bridge VS Temperature

#age 7$%

T e m p e r a t u r e < o 4 =

Voltage <V=



Results obtained across the Voltage Divider

(ing the oltage drop mea(ured a+ro(( the arying re(i(tan+e i"e" the thermi(tor in thi( +a(e the

re(i(tan+e in ea+h +a(e i( determined" (ing thi( re(i(tan+e the alue o' temperature 'or ea+h +a(e

i( determined by u(ing the (ame pro+edure 'ollo*ed to determine re(ult( a+ro(( *heat(tone

bridge"

Table %: Values obtained from wheatstone bridge$

ThermistorVolatage drop

(V)

Temperature

TMP36(C)

Resistanceo

thermistor(ohm)

T(C) ΔT (C)Absolute ΔT(C)

0.4509747 44.16054 4574.319 43.8480

8

-0.3124

6

0.3124

65

0.4542387 44.39312 4496.561 44.2844

9

-

0.1086

3

0.1086

25

0.4584803 44.19129 4527.346 44.1106

9

-

0.0806

0.0805

98

0.174178 35.96326 5351.357 39.9028

6

3.9396

04

3.9396

04

0.1779825 35.96668 5363.825 39.845 3.8783

17

3.8783

17

0.1849678 35.91937 5374.478 39.7956

7

3.8763

01

3.8763

01

0.02362121 2.836431 29763.42 1.76348

-

1.0729

5

1.0729

51

0.03038571 2.871909 29815.32 1.72886

5

-

1.1430

4

1.1430

44

0.3129807 46.11736 4375.508 44.9813

3

-

1.1360

3

1.1360

25

0.3233639 46.12682 4358.322 45.08204

-

1.0447

8

1.044775

&n +omparing the alue( o' temperature obtained 'rom thermi(tor *ith the temperature read by

the TM# -% (en(or an aerage ab(olute error o' about degree +entigrade <"9>& 4= i( ob(ered" A(

the TM# -% (en(or ha( an a++ura+y o' ; 2 degree( +entigrade the alue( mea(ured a+ro(( the

thermi(tor 'all *ithin the range o' alue( that a TM# -% (en(or might read" A( there i( no

noti+eable o''(et in the alue( obtained a( noti+ed 'rom the graph there i( no (y(temati+ error

#age !$%



a((o+iated *ith the (en(or" There'ore the error noti+ed in the +al+ulated alue( +an be attributed to

random error a((o+iated *ith the tran(du+er +on'iguration and the (en(or u(ed"

Figure ': Voltage across oltage diider VS Temperature$

Comparing values obtained from wheatstone bridge to those across Voltage divider

?en though the ma)imum error in the +al+ulated alue( *a( about the (ame in both +a(e( *hi+h

+an be noti+ed in the table( and 2, the alue( mea(ured a+ro(( the *heat(tone bridge *ere 'ound

to be (lightly more a++urate than the alue( mea(ured u(ing the oltage diider *hi+h +an be

noti+ed in the 'igure( 2 and -" Thi( i( to be e)pe+ted a( *heat(tone bridge i( a re'ined er(ion o'

the oltage diider" The random error a((o+iated *ith the reading( 'rom both the tran(du+er

+on'iguration( +an be attributed to hy(tere(i( by ob(ering 'igure( 2 and -"

Design stage uncertainty!

The de(ign (tage un+ertainty o' the temperature mea(ured a+ro(( the thermi(tor in *heat(tone

bridge +on'iguration *a( determined 'or a range o' output oltage( and graph *a( plotted"

#age %$%

Voltage <V=

T

e m p e r a t u r e < o 4 =



Figure : Temperature across output oltage across wheatstone bridge transducer sstem

Conclusions@a(ed on the alue( obtained +alibration o' thermi(tor i( not reuired a( the alue( mea(ured

a+ro(( the thermi(tor lie *ithin the a++ura+y limit( (pe+i'ied by the TM# -% data(heet" The alue(

mea(ured a+ro(( *heat(tone bridge *ere 'ound to be more a++urate than the alue( mea(ure

a+ro(( the oltage diider a( the random error a((o+iated *ith the alue( mea(ured a+ro(( the

oltage diider +on'iguration *a( 'ound to be (lightly larger than the alue( obtained a+ro((

*heat(tone bridge"

Appendix

Design "tage #ncertainity $nalysis

Table ': Uncertainit in Vout and temperatures oer a range of Vout

Vout(V)

ResistanceThermistor(ohm)

T(C) !ncertainit"in Vout

T(min) T(ma#)

-2.2 638.2979 102.02

54 0.273381342

79.064

4

209.36

74

-2.1 869.5652 91.671

2 0.278914409

73.234

3

137.23

68

-2 1111.111 83.822

71 0.28452581

68.261

59

114.36

17

#age >$%

T e m p e r a t u r e < & 4 =

Voltage <V=



-1.9 1363.636 77.494

93 0.290185346

63.912

62

100.85

13

-1.8 1627.907 72.181

78 0.295868273

60.035

52

91.306

65

-1.7 1904.762 67.589

9 0.301554199

56.526

09

83.931

33

-1.6 2195.122 63.534

54 0.307226298

53.309

76

77.913

71

-1.5 2500 59.891

98 0.312870734

50.331

31

72.820

34

-1.4 2820.513 56.575

42 0.318476203

47.548

65

68.393

42

-1.3 3157.895 53.521

61 0.324033569

44.928

88

64.467

58

-1.2 3513.514 50.683

01 0.329535562

42.445

79

60.930

54

-1.1 3888.889 48.022

98 0.33497653 40.078

57.702

72

-1 4285.714 45.512

6 0.340352236

37.807

84

54.725

6

-0.9 4705.882 43.128

61 0.345659675

35.620

4

51.954

96

-0.8 5151.515 40.851

96 0.350896935

33.502

94

49.356

49

-0.7 5625 38.666

8 0.356063062

31.444

35

46.903

05

-0.6 6129.032 36.559

72 0.361157958

29.434

81

44.572

73

-0.5 6666.667 34.519

2

0.366182284 27.465

51

42.347

54

-0.4 7241.379 32.535

23 0.371137381

25.528

35

40.212

51

-0.3 7857.143 30.598

95 0.376025199

23.615

81

38.154

98

-0.2 8518.519 28.702

4 0.380848236

21.720

74

36.164

1

-0.1 9230.769 26.838

33 0.385609483

19.836

19

34.230

44

0 10000 25.000

04 0.390312378

17.955

31

32.345

7

0.1 10833.33

23.181

19 0.395214923

16.066

57

30.507

35

0.2 11739.13 21.375

71 0.400057549

14.167

46

28.703

48

0.3 12727.27 19.577

68 0.404841266

12.250

42

26.927

93

0.4 13809.52 17.781

18 0.409567601

10.307

23

25.174

98

0.5 15000 15.980 0.414238579 8.3288 23.439

#age $%



2 4 21

0.6 16315.79 14.168

51 0.418856724

6.3049

73

21.715

42

0.7 17777.78 12.339

52 0.423425057

4.2237

66

19.998

51

0.8 19411.76

10.486

12 0.427947095

2.0711

74

18.283

44

0.9 21250 8.6004

54 0.432426855

-

0.1698

1

16.565

06

1 23333.33 6.6737

01 0.436868862

-

2.5203

2

14.838

11

1.1 25714.29 4.6957

4 0.441278154

-

5.0073

2

13.097

04

1.2 28461.54

2.6547

15 0.445660295

-

7.66626

11.335

9

1.3 31666.67 0.5364

4 0.450021394

-

10.545

5

9.5482

49

1.4 35454.55

-

1.6764

3

0.45436812

-

13.713

9

7.7269

12

1.5 40000

-

4.0056

5

0.458707736

-

17.274

9

5.8637

95

1.6 45555.56

-

6.47918

0.463048127

-

21.3957

3.9495

86

1.7 52500

-

9.1341

5

0.467397856

-

26.375

1

1.9733

67

1.8 61428.57

-

12.021

6

0.471766219

-

32.839

7

-

0.0779

1

1.9 73333.33

-

15.215

1

0.476163342

-

42.547

9

-

2.2201

5

2 90000

-

18.8263

0.480600315

-

67.8673

-

4.47322

#age 9$%



%heatstone &ridge

Table : Temperature and absolute difference in temperature at arious output oltages in

wheatstone bridge configuration

thermistor$bridge (V)

Temp$TMP36 (C)

Resistance(ohm)

T(C) Absolute

ΔT

0.9887555 45.95495 4340.62815 45.18621

0.768740089

0.9869428 45.79175 4348.078972 45.142

29

0.649461

997

0.9857133 45.69477 4353.137059 45.112

52

0.582250

022

0.9829941 45.70187 4364.336381 45.046

75

0.655120

408

#age 0$%



0.9819932 45.68847 4368.463108 45.022

56

0.665906

93

0.9790376 45.59149 4380.662974 44.951

21

0.640277

458

0.9762554 45.54182 4392.166079 44.884

14

0.657675

574

0.9759874 45.53 4393.275109 44.877

69

0.652311

101

0.7331726 39.93944 5473.754158 39.341

3

0.598144

166

0.7112146 39.40648 5579.532764 38.867

38

0.539104

527

0.7019696 39.55785 5624.503568 38.668

98

0.888867

054

0.6989037 39.34025 5639.474632 38.603

34

0.736912

731

0.6991007 39.23382 5638.511799 38.607

55

0.626266

84

0.6897295 39.1873 5684.445266 38.407

34

0.779964

706

0.6832036 39.06352 5716.592347 38.268

3

0.795216

971

0.6787348 38.92161 5738.682266 38.173

28

0.748328

242

0.1589781 28.92467 8815.463382 27.904

52

1.020145

85

0.1583554 28.84504 8819.872579 27.892

91

0.952132

38

0.1570471 28.77014 8829.143098 27.868

5

0.901635

154

0.1117088 27.96057 9156.156712 27.025

82

0.934746

96

-0.7025539 12.86964 17846.28581 12.258

02

0.611619

918

-0.70894 12.73955 17945.76201 12.140

3

0.599251

658

-0.7156178 12.60789 18050.54585 12.017

09

0.590801

572

-0.7186452 12.53772 18098.3095 11.961

19

0.576527

111

-0.7206399 12.50461 18129.86921

11.924

35

0.580258

779

-0.7221615 12.48253 18153.99139 11.896

24

0.586289

432

-0.7330493 12.46204 18327.81342 11.694

91

0.767125

238

-0.7416429 12.2468 18466.53355 11.535

78

0.711016

877

-0.7572533 12.02211 18722.03115 11.246 0.775923

#age $%



19 056

-1.006743 6.961352 23532.99876 6.4992

85

0.462067

222

-1.01026 6.906164 23612.37715 6.4304

06

0.475757

76

-1.013106 6.905376 23676.88701

6.3746

21

0.530754

908

-1.020115 6.905376 23836.82076 6.2370

52

0.668324

022

-1.025192 6.905376 23953.62229 6.1372

38

0.768137

968

0.9820326 45.90528 4368.300616 45.023

51

0.881765

067

0.9921683 46.13628 4326.621387 45.269

01

0.867268

084

0.9919397 46.18201 4327.558746 45.263

46

0.918548

903

0.9874393 46.14022 4346.037415 45.15431

0.985905754

#age 2$%



Voltage Divider

Table : Temperature and absolute difference in temperature at arious output oltages inVoltage *iider configuration

VolatageThermistor(%olt)

Temp$TMP36 (C)

Resistance o thermistor(oh

m)T(C) ΔT

2.213574 29.84 7944.133453 30.339

35

0.4993

48

2.076022 32.94315 7099.99186 33.006

29

0.0631

38

2.059899 33.28217 7006.218494 33.324

63

0.0424

55

2.056848 33.46823 6988.589104 33.385

01

-

0.0832

2

2.0609 33.54076 7012.010479 33.304

82

-

0.2359

4

2.062051 33.45325 7018.675273 33.282

06

-

0.1711

9

2.061618 33.36495 7016.167401 33.290

62

-

0.0743

3

2.138897 31.81731 7475.777698 31.776

87

-

0.0404

4

2.242059 30.28624 8129.466874 29.796

87

-

0.4893

7

2.314159 29.11704 8616.142951 28.436 -

#age -$%



65 0.6803

9

2.369796 28.1205 9009.932309 27.398

34

-

0.7221

6

2.260106 30.35956 8248.881161 29.45472

-

0.9048

4

1.682215 42.3346 5070.295393 41.249

76

-

1.0848

4

1.569308 44.16054 4574.319117 43.848

08

-

0.3124

6

1.550906 44.39312 4496.560546 44.284

49

-

0.1086

3

1.547847 44.37499 4483.714945 44.35742

-

0.0175

7

1.550938 44.33399 4496.695043 44.283

73

-

0.0502

6

1.553989 44.23623 4509.530004 44.211

11

-

0.0251

2

1.554675 44.22756 4512.419003 44.194

79

-

0.0327

7

3.067438 14.70189 15872.39116 14.76 0.058112

3.279565 11.03109 19062.41735 10.867

22

-

0.1638

7

3.403605 8.693472 21320.56916 8.5317

65

-

0.1617

1

3.505104 7.912954 23447.14281 6.5740

79

-

1.3388

8

3.587421 6.941642 25396.2504

4.9477

51

-

1.99389

3.632778 4.973002 26570.50574 4.0343

18

-

0.9386

8

3.657131 3.97173 27233.71379 3.5382

53

-

0.4334

8

#age 7$%



3.682754 3.460057 27957.98203 3.0117

92

-

0.4482

7

3.701857 3.020917 28516.55788 2.6161

3

-

0.4047

9

3.716482 2.805683 28955.43343 2.3113

17

-

0.4943

7

3.726866 2.77257 29273.1637 2.0938

64

-

0.6787

1

3.734072 2.718171 29496.71703 1.9424

47

-

0.7757

2

3.738092 2.710287 29622.53984 1.8577

91

-

0.8525

3.742563 2.836431 29763.42354 1.76348

-

1.0729

5

3.744202 2.871909 29815.32062 1.7288

65

-

1.1430

4

1.661638 44.04701 4977.405087 41.713

71

-

2.3333

1.541509 45.51029 4457.172218 44.508

86

-

1.0014

3

1.521862 46.11736 4375.507815

44.981

33

-

1.13603

1.517699 46.12682 4358.32227 45.082

04

-

1.0447

8

1.517581 46.10711 4357.835746 45.084

9

-

1.0222

1

1.519173 46.10159 4364.402483 45.046

36

-

1.0552

3

1.518101 46.07636 4359.979999

45.072

31

-

1.00405

1.517825 46.0464 4358.841816 45.078

99

-

0.9674

1

1.518235 45.98569 4360.532661 45.069

07

-

0.9166

2

#age !$%



1.518606 45.90922 4362.063013 45.060

08

-

0.8491

4

#age %$%

emda lab report 1

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