Question

For a certain temperature measurement, A thermistor of 10 k ohm at 25oC nominal resistance was used. Its resistance at 0oC is 29.49 k ohm: 1) Calculate and plot the resistance of the thermistor between -75oC and + ‏75oC.2) Indicate the type of this thermistor and discuss the obtained graph.

Answer 1

1)

OUTPUT FROM MATLAB:

T =

Columns 1 through 6

-75 -74 -73 -72 -71 -70

Columns 7 through 12

-69 -68 -67 -66 -65 -64

Columns 13 through 18

-63 -62 -61 -60 -59 -58

Columns 19 through 24

-57 -56 -55 -54 -53 -52

Columns 25 through 30

-51 -50 -49 -48 -47 -46

Columns 31 through 36

-45 -44 -43 -42 -41 -40

Columns 37 through 42

-39 -38 -37 -36 -35 -34

Columns 43 through 48

-33 -32 -31 -30 -29 -28

Columns 49 through 54

-27 -26 -25 -24 -23 -22

Columns 55 through 60

-21 -20 -19 -18 -17 -16

Columns 61 through 66

-15 -14 -13 -12 -11 -10

Columns 67 through 72

-9 -8 -7 -6 -5 -4

Columns 73 through 78

-3 -2 -1 0 1 2

Columns 79 through 84

3 4 5 6 7 8

Columns 85 through 90

9 10 11 12 13 14

Columns 91 through 96

15 16 17 18 19 20

Columns 97 through 102

21 22 23 24 25 26

Columns 103 through 108

27 28 29 30 31 32

Columns 109 through 114

33 34 35 36 37 38

Columns 115 through 120

39 40 41 42 43 44

Columns 121 through 126

45 46 47 48 49 50

Columns 127 through 132

51 52 53 54 55 56

Columns 133 through 138

57 58 59 60 61 62

Columns 139 through 144

63 64 65 66 67 68

Columns 145 through 150

69 70 71 72 73 74

Column 151

75

R =

Columns 1 through 4

87.9687 87.1890 86.4092 85.6295

Columns 5 through 8

84.8498 84.0701 83.2904 82.5107

Columns 9 through 12

81.7309 80.9512 80.1715 79.3918

Columns 13 through 16

78.6121 77.8324 77.0527 76.2729

Columns 17 through 20

75.4932 74.7135 73.9338 73.1541

Columns 21 through 24

72.3744 71.5946 70.8149 70.0352

Columns 25 through 28

69.2555 68.4758 67.6961 66.9163

Columns 29 through 32

66.1366 65.3569 64.5772 63.7975

Columns 33 through 36

63.0178 62.2381 61.4583 60.6786

Columns 37 through 40

59.8989 59.1192 58.3395 57.5598

Columns 41 through 44

56.7800 56.0003 55.2206 54.4409

Columns 45 through 48

53.6612 52.8815 52.1018 51.3220

Columns 49 through 52

50.5423 49.7626 48.9829 48.2032

Columns 53 through 56

47.4235 46.6437 45.8640 45.0843

Columns 57 through 60

44.3046 43.5249 42.7452 41.9654

Columns 61 through 64

41.1857 40.4060 39.6263 38.8466

Columns 65 through 68

38.0669 37.2872 36.5074 35.7277

Columns 69 through 72

34.9480 34.1683 33.3886 32.6089

Columns 73 through 76

31.8291 31.0494 30.2697 29.4900

Columns 77 through 80

28.7103 27.9306 27.1509 26.3711

Columns 81 through 84

25.5914 24.8117 24.0320 23.2523

Columns 85 through 88

22.4726 21.6928 20.9131 20.1334

Columns 89 through 92

19.3537 18.5740 17.7943 17.0146

Columns 93 through 96

16.2348 15.4551 14.6754 13.8957

Columns 97 through 100

13.1160 12.3363 11.5565 10.7768

Columns 101 through 104

9.9971 9.2174 8.4377 7.6580

Columns 105 through 108

6.8782 6.0985 5.3188 4.5391

Columns 109 through 112

3.7594 2.9797 2.2000 1.4202

Columns 113 through 116

0.6405 -0.1392 -0.9189 -1.6986

Columns 117 through 120

-2.4783 -3.2581 -4.0378 -4.8175

Columns 121 through 124

-5.5972 -6.3769 -7.1566 -7.9363

Columns 125 through 128

-8.7161 -9.4958 -10.2755 -11.0552

Columns 129 through 132

-11.8349 -12.6146 -13.3944 -14.1741

Columns 133 through 136

-14.9538 -15.7335 -16.5132 -17.2929

Columns 137 through 140

-18.0727 -18.8524 -19.6321 -20.4118

Columns 141 through 144

-21.1915 -21.9712 -22.7509 -23.5307

Columns 145 through 148

-24.3104 -25.0901 -25.8698 -26.6495

Columns 149 through 151

-27.4292 -28.2090 -28.9887

Plot:

2)

This is a negative temperature coefficient thermistor (NTC). Resistance varies linearly with temperature.