RTD Overview

RTD Description

BAPI RTDs (Resistance Temperature Detectors) are thermally sensitive resistive elements that exhibit a small change in resistance per degree of temperature change. RTDs are especially recognized for excellent linearity throughout their temperature range with a high degree of accuracy and repeatability. An example of an RTD output curve can be seen in Figure 2.

RTDs supplied in BAPI products feature a standard interchangeability tolerance of ±0.3 °C measured at 0 °C. Higher accuracy sensors are also available. The Class A line [A] has an interchangeability tolerance of ± 0.15 °C measured at 0 °C. Please call for availability and pricing on Class A RTDs. Whether standard or Class A, BAPI RTDs have such a high accuracy that they can be interchanged without the expense of offsetting the controller.

Most RTD sensing elements can be packaged to withstand an extremely broad temperature range (‑200 to 600°C). For most purposes, the standard operating range should be sufficient, but we also have RTDs with a higher or lower operating temperature range. BAPI offers 1 kΩ Platinum RTDs with the ranges shown in the table at right.

Typical RTD Output Curve 1000 Ohm Sensor
Standard & Extreme Temperature Ranges for the 1 KΩ Platinum RTD
Range °C °F
Standard -60 to 150 -76 to 302
Low Temp[1] -200 to 0 -328 to 32
High Temp[2] 25 to 260 77 to 500
Very High Temp[3] 25 to 600 77 to 1112

When ordering a sensor with an "extreme" temperature range, included the number in brackets [] after the sensor type. Ex: BA/1K[2] is a 1kΩ RTD with an operating range of 100 to 210°C.

Definition of Specification Terms

Tolerance of Resistance (Accuracy)
The maximum amount any RTD will differ from the standard resistance curve.

Stability (drift)
The amount that the resistance characteristics of a RTD will change over time under certain conditions.

Operating Range
The operating range shown is for the RTD sensor only. The mounting package may further limit the operating range and is described on each mounting type specification.

RTD Specifications

Tolerance of Resistance (Accuracy):

Single Point Standard: 0.12% at 0 °C
Single Point Class A: 0.06% at 0 °C
Averaging Standard: 0.2% at 0 °C

Tolerance in °C:

Single Point Standard: ±(0.3 + 0.005T); T= Temp in °C
Single Point Class A: ±(0.15 + 0.002T); T= Temp in °C
Averaging Standard: ±(0.5 + 0.005(T-25)); T= Temp in °C

Stability (drift):

0.14 °C with 6,000 continuous hours at 400 °C

Sensitivity:

1KΩ: 3.85Ω/°C (2.14Ω/°F)

Self Heating (1K RTD only):

0.4°C/mW at 0°C

Standardization:

DIN 43760-1980, IEC Pub 751-1983, JIS C1604-1989

Sensor Type Reference Resistance Temperature Coefficient Operating Range
BA/1K[375]* 1 kΩ @ 0°C 3.75Ω/°C -60 to 150°C
BA/1K[Ni] 1 kΩ @ 21°C 5.68Ω/°C -60 to 200°C
BA/1K* 1 kΩ @ 0°C 3.85Ω/°C -60 to 150°C
BA/2K 2 kΩ @ 20°C 8Ω/°C -60 to 150°C
*Available as an [A] high accuracy sensor. Example: BA/1K[A]-I-2” (high accuracy immersion sensor)

1K (375) PLATINUM RTD OUTPUT TABLE

°F °C Ohms
-40 -40.00 846.64
-38 -38.89 850.92
-36 -37.78 855.20
-34 -36.67 859.48
-32 -35.56 863.76
-30 -34.44 868.07
-28 -33.33 872.34
-26 -32.22 876.62
-24 -31.11 880.89
-22 -30.00 885.16
-20 -28.89 889.43
-18 -27.78 893.69
-16 -26.67 897.96
-14 -25.56 902.22
-12 -24.44 906.52
-10 -23.33 910.79
-8 -22.22 915.04
-6 -21.11 919.30
-4 -20.00 923.56
-2 -18.89 927.81
0 -17.78 932.07
2 -16.67 936.32
4 -15.56 940.57
6 -14.44 944.86
8 -13.33 949.11
10 -12.22 953.35
12 -11.11 957.60
14 -10.00 961.84
16 -8.89 966.08
18 -7.78 970.32
20 -6.67 974.56
22 -5.56 978.80
24 -4.44 983.07
26 -3.33 987.31
28 -2.22 991.54
30 -1.11 995.77
32 0.00 1,000.00
34 1.11 1,004.23
°F °C Ohms
36 2.22 1,008.46
38 3.33 1,012.68
40 4.44 1,016.90
42 5.56 1,021.16
44 6.67 1,025.39
46 7.78 1,029.61
48 8.89 1,033.82
50 10.00 1,038.04
52 11.11 1,042.25
54 12.22 1,046.47
56 13.33 1,050.68
58 14.44 1,054.89
60 15.56 1,059.14
62 16.67 1,063.35
64 17.78 1,067.55
66 18.89 1,071.76
68 20.00 1,075.96
70 21.11 1,080.16
72 22.22 1,084.36
74 23.33 1,088.56
76 24.44 1,092.76
78 25.56 1,096.99
80 26.67 1,101.18
82 27.78 1,105.38
84 28.89 1,109.57
86 30.00 1,113.76
88 31.11 1,117.95
90 32.22 1,122.13
92 33.33 1,126.32
94 34.44 1,130.50
96 35.56 1,134.72
98 36.67 1,138.90
100 37.78 1,143.08
102 38.89 1,147.26
104 40.00 1,151.44
106 41.11 1,155.61
108 42.22 1,159.79
110 43.33 1,163.96
°F °C Ohms
112 44.44 1,168.13
114 45.56 1,172.33
116 46.67 1,176.50
118 47.78 1,180.67
120 48.89 1,184.83
122 50.00 1,189.00
124 51.11 1,193.16
126 52.22 1,197.32
128 53.33 1,201.48
130 54.44 1,205.63
132 55.56 1,209.83
134 56.67 1,213.98
136 57.78 1,218.13
138 58.89 1,222.28
140 60.00 1,226.43
142 61.11 1,230.58
144 62.22 1,234.73
146 63.33 1,238.87
148 64.44 1,243.02
150 65.56 1,247.20
152 66.67 1,251.34
154 67.78 1,255.48
156 68.89 1,259.61
158 70.00 1,263.75
160 71.11 1,267.89
162 72.22 1,272.02
164 73.33 1,276.15
166 74.44 1,280.28
168 75.56 1,284.45
170 76.67 1,288.57
172 77.78 1,292.70
174 78.89 1,296.82
176 80.00 1,300.95
178 81.11 1,305.07
180 82.22 1,309.19
182 83.33 1,313.31
184 84.44 1,317.42
186 85.56 1,321.58

1K (Ni) NICKEL RTD OUTPUT TABLE

°F °C Ohms
-40 -40.00 699.28
-38 -38.89 704.37
-36 -37.78 709.47
-34 -36.67 714.58
-32 -35.56 719.70
-30 -34.44 724.84
-28 -33.33 729.98
-26 -32.22 735.14
-24 -31.11 740.31
-22 -30.00 745.49
-20 -28.89 750.68
-18 -27.78 755.89
-16 -26.67 761.11
-14 -25.56 766.35
-12 -24.44 771.60
-10 -23.33 776.86
-8 -22.22 782.14
-6 -21.11 787.44
-4 -20.00 792.75
-2 -18.89 798.07
0 -17.78 803.41
2 -16.67 808.76
4 -15.56 814.13
6 -14.44 819.52
8 -13.33 824.92
10 -12.22 830.34
12 -11.11 835.77
14 -10.00 841.22
16 -8.89 846.69
18 -7.78 852.17
20 -6.67 857.66
22 -5.56 863.18
24 -4.44 868.71
26 -3.33 874.25
28 -2.22 879.81
30 -1.11 885.39
32 0.00 890.98
34 1.11 896.59
°F °C Ohms
36 2.22 902.21
38 3.33 907.85
40 4.44 913.51
42 5.56 919.18
44 6.67 924.87
46 7.78 930.57
48 8.89 936.29
50 10.00 942.02
52 11.11 947.77
54 12.22 953.53
56 13.33 959.31
58 14.44 965.11
60 15.56 970.92
62 16.67 976.74
64 17.78 982.59
66 18.89 988.44
68 20.00 994.31
70 21.11 1000.20
72 22.22 1006.10
74 23.33 1012.02
76 24.44 1017.95
78 25.56 1023.89
80 26.67 1029.86
82 27.78 1035.83
84 28.89 1041.82
86 30.00 1047.83
88 31.11 1053.85
90 32.22 1059.89
92 33.33 1065.94
94 34.44 1072.00
96 35.56 1078.08
98 36.67 1084.18
100 37.78 1090.29
102 38.89 1096.42
104 40.00 1102.56
106 41.11 1108.71
108 42.22 1114.89
110 43.33 1121.07
°F °C Ohms
112 44.44 1127.27
114 45.56 1133.49
116 46.67 1139.72
118 47.78 1145.97
120 48.89 1152.24
122 50.00 1158.52
124 51.11 1164.81
126 52.22 1171.12
128 53.33 1177.45
130 54.44 1183.79
132 55.56 1190.15
134 56.67 1196.53
136 57.78 1202.92
138 58.89 1209.33
140 60.00 1215.75
142 61.11 1222.19
144 62.22 1228.65
146 63.33 1235.12
148 64.44 1241.62
150 65.56 1248.13
152 66.67 1254.65
154 67.78 1261.20
156 68.89 1267.76
158 70.00 1274.34
160 71.11 1280.93
162 72.22 1287.55
164 73.33 1294.18
166 74.44 1300.83
168 75.56 1307.50
170 76.67 1314.19
172 77.78 1320.89
174 78.89 1327.62
176 80.00 1334.36
178 81.11 1341.12
180 82.22 1347.90
182 83.33 1354.70
184 84.44 1361.52
186 85.56 1368.36

1KΩ PLATINUM RTD OUTPUT TABLE

°F °C Ohms
-40.00 -40.00 842.75
-38.00 -38.89 847.14
-36.00 -37.78 851.53
-34.00 -36.67 855.91
-32.00 -35.56 860.30
-30.00 -34.44 864.72
-28.00 -33.33 869.10
-26.00 -32.22 873.48
-24.00 -31.11 877.86
-22.00 -30.00 882.24
-20.00 -28.89 886.61
-18.00 -27.78 890.99
-16.00 -26.67 895.36
-14.00 -25.56 899.73
-12.00 -24.44 904.14
-10.00 -23.33 908.51
-8.00 -22.22 912.88
-6.00 -21.11 917.24
-4.00 -20.00 921.61
-2.00 -18.89 925.97
0.00 -17.78 930.33
2.00 -16.67 934.69
4.00 -15.56 939.05
6.00 -14.44 943.45
8.00 -13.33 947.80
10.00 -12.22 952.16
12.00 -11.11 956.51
14.00 -10.00 960.86
16.00 -8.89 965.21
18.00 -7.78 969.56
20.00 -6.67 973.91
22.00 -5.56 978.25
24.00 -4.44 982.64
26.00 -3.33 986.98
28.00 -2.22 991.32
30.00 -1.11 995.66
32.00 0.00 1000.00
34.00 1.11 1004.34
°F °C Ohms
36.00 2.22 1008.67
38.00 3.33 1013.01
40.00 4.44 1017.34
42.00 5.56 1021.71
44.00 6.67 1026.04
46.00 7.78 1030.37
48.00 8.89 1034.70
50.00 10.00 1039.02
52.00 11.11 1043.35
54.00 12.22 1047.67
56.00 13.33 1051.99
58.00 14.44 1056.31
60.00 15.56 1060.67
62.00 16.67 1064.99
64.00 17.78 1069.30
66.00 18.89 1073.62
68.00 20.00 1077.93
70.00 21.11 1082.24
72.00 22.22 1086.55
74.00 23.33 1090.86
76.00 24.44 1095.17
78.00 25.56 1099.51
80.00 26.67 1103.81
82.00 27.78 1108.12
84.00 28.89 1112.42
86.00 30.00 1116.72
88.00 31.11 1121.02
90.00 32.22 1125.31
92.00 33.33 1129.61
94.00 34.44 1133.90
96.00 35.56 1138.24
98.00 36.67 1142.53
100.00 37.78 1146.82
102.00 38.89 1151.11
104.00 40.00 1155.39
106.00 41.11 1159.68
108.00 42.22 1163.96
110.00 43.33 1168.25
°F °C Ohms
112.00 44.44 1172.53
114.00 45.56 1176.85
116.00 46.67 1181.12
118.00 47.78 1185.40
120.00 48.89 1189.68
122.00 50.00 1193.95
124.00 51.11 1198.22
126.00 52.22 1202.49
128.00 53.33 1206.76
130.00 54.44 1211.03
132.00 55.56 1215.34
134.00 56.67 1219.60
136.00 57.78 1223.87
138.00 58.89 1228.13
140.00 60.00 1232.39
142.00 61.11 1236.65
144.00 62.22 1240.91
146.00 63.33 1245.17
148.00 64.44 1249.42
150.00 65.56 1253.72
152.00 66.67 1257.97
154.00 67.78 1262.22
156.00 68.89 1266.47
158.00 70.00 1270.72
160.00 71.11 1274.97
162.00 72.22 1279.21
164.00 73.33 1283.46
166.00 74.44 1287.70
168.00 75.56 1291.98
170.00 76.67 1296.22
172.00 77.78 1300.46
174.00 78.89 1304.69
176.00 80.00 1308.93
178.00 81.11 1313.16
180.00 82.22 1317.40
182.00 83.33 1321.63
184.00 84.44 1325.86
186.00 85.56 1330.12

2KΩ SILICON RTD OUTPUT TABLE

°F °C Ohms
-40 -40.00 1,583.9
-38 -38.89 1,591.0
-36 -37.78 1,598.1
-34 -36.67 1,605.3
-32 -35.56 1,612.4
-30 -34.44 1,619.7
-28 -33.33 1,626.9
-26 -32.22 1,634.1
-24 -31.11 1,641.4
-22 -30.00 1,648.7
-20 -28.89 1,656.0
-18 -27.78 1,663.3
-16 -26.67 1,670.6
-14 -25.56 1,678.0
-12 -24.44 1,685.5
-10 -23.33 1,692.9
-8 -22.22 1,700.3
-6 -21.11 1,707.8
-4 -20.00 1,715.3
-2 -18.89 1,722.8
0 -17.78 1,730.3
2 -16.67 1,737.9
4 -15.56 1,745.4
6 -14.44 1,753.1
8 -13.33 1,760.7
10 -12.22 1,768.4
12 -11.11 1,776.0
14 -10.00 1,783.7
16 -8.89 1,791.4
18 -7.78 1,799.2
20 -6.67 1,806.9
22 -5.56 1,814.7
24 -4.44 1,822.6
26 -3.33 1,830.4
28 -2.22 1,838.2
30 -1.11 1,846.1
32 0.00 1,854.0
34 1.11 1,861.9
°F °C Ohms
36 2.22 1,869.9
38 3.33 1,877.8
40 4.44 1,885.8
42 5.56 1,893.9
44 6.67 1,901.9
46 7.78 1,909.9
48 8.89 1,918.0
50 10.00 1,926.1
52 11.11 1,934.2
54 12.22 1,942.4
56 13.33 1,950.5
58 14.44 1,958.7
60 15.56 1,967.0
62 16.67 1,975.2
64 17.78 1,983.5
66 18.89 1,991.8
68 20.00 2,000.1
70 21.11 2,008.4
72 22.22 2,016.7
74 23.33 2,025.1
76 24.44 2,033.5
78 25.56 2,042.0
80 26.67 2,050.4
82 27.78 2,058.8
84 28.89 2,067.3
86 30.00 2,075.8
88 31.11 2,084.4
90 32.22 2,092.9
92 33.33 2,101.5
94 34.44 2,110.1
96 35.56 2,118.8
98 36.67 2,127.4
100 37.78 2,136.0
102 38.89 2,144.7
104 40.00 2,153.4
106 41.11 2,162.2
108 42.22 2,170.9
110 43.33 2,179.7
°F °C Ohms
112 44.44 2,188.5
114 45.56 2,197.4
116 46.67 2,206.2
118 47.78 2,215.1
120 48.89 2,224.0
122 50.00 2,232.9
124 51.11 2,241.8
126 52.22 2,250.8
128 53.33 2,259.7
130 54.44 2,268.7
132 55.56 2,277.8
134 56.67 2,286.9
136 57.78 2,295.9
138 58.89 2,305.0
140 60.00 2,314.1
142 61.11 2,323.3
144 62.22 2,332.4
146 63.33 2,341.6
148 64.44 2,350.8
150 65.56 2,360.1
152 66.67 2,369.4
154 67.78 2,378.6
156 68.89 2,387.9
158 70.00 2,397.2
160 71.11 2,406.6
162 72.22 2,415.9
164 73.33 2,425.3
166 74.44 2,434.7
168 75.56 2,444.2
170 76.67 2,453.7
172 77.78 2,463.2
174 78.89 2,472.7
176 80.00 2,482.2
178 81.11 2,491.7
180 82.22 2,501.3
182 83.33 2,510.9
184 84.44 2,520.5
186 85.56 2,530.2