RTD Overview
Resistance Temperature Detectors with excellent linearity, accuracy, and repeatability
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.
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 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 1KΩ Platinum RTDs with various ranges to meet your specific application needs.
Definition of Specification Terms
Tolerance of Resistance (Accuracy)
The maximum amount that RTDs following the same curve will differ from each other.
Stability (drift)
The amount that the RTD resistance characteristics will change. BAPI uses only the highest quality, film platinum RTD sensors with very small drift values.
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)
Range: ±0.06 of the absolute ohm value at 0°C in accordance with Standard 1/3 DIN
Tolerance % (%)
Range: ±0.0 ± (0.02 x t (0.0111 + t)); t= temp °C
Example: At 0°C - Range ±0.02°C, At 100°C - Range ±0.13°C
Averaging Standard: ±0.0 ± (0.0052 + (0.01 x temp °C))
Stability (drift)
±0.1°C over a 5,000 continuous hours at 65°C
Sensitivity
1KΩ: 2.13Ω/°C (at 70°F)
100Ω: 0.385Ω/°C
Self Heating (in RTD only)
0.4°C/mW in air
Standard & Internal Temperature Ranges for the 1KΩ Platinum RTD
| Symbol | Reference Resistance | Temperature Coefficient | Operating Range |
|---|---|---|---|
| 1KΩ (375) | 1000Ω±1000 | 3.75 (Ω/°C) | -80 to 200°C |
| 1KΩ (385) | 1000.0±1.0Ω | 3.850 (Ω/°C) | -65 to 260°C |
| 1KΩ (392) | 1000.0±2.0Ω | 3.916 (Ω/°C) | -70 to 205°C |
Interchangeability Tolerance Comparison
Standard RTD
Tolerance: ±0.3°C at 0°C
Best For: General HVAC applications
Benefit: Cost-effective high accuracy
Class A RTD
PREMIUMTolerance: ±0.15°C at 0°C
Best For: Critical applications
Benefit: Maximum precision
Key RTD Features
Exceptional Accuracy
Class A RTDs provide industry-leading accuracy for critical applications
Excellent Linearity
Predictable output throughout the entire temperature range
Wide Range
Extremely broad temperature range for diverse applications
RTD Output Tables
Detailed resistance vs. temperature tables showing precise ohm values for each RTD type across their full operating range. These tables are essential for system integration and troubleshooting.
1KΩ PLATINUM RTD OUTPUT TABLE
| °F | °C | Ohms | °F | °C | Ohms | °F | °C | Ohms |
|---|---|---|---|---|---|---|---|---|
| -40 | -40.00 | 842.7 | 14 | -10.00 | 960.9 | 68 | 20.00 | 1077.9 |
| -38 | -38.89 | 847.0 | 16 | -8.89 | 965.2 | 70 | 21.11 | 1082.2 |
| -36 | -37.78 | 851.2 | 18 | -7.78 | 969.4 | 72 | 22.22 | 1086.4 |
| -34 | -36.67 | 855.5 | 20 | -6.67 | 973.7 | 74 | 23.33 | 1090.6 |
| -32 | -35.56 | 859.8 | 22 | -5.56 | 977.9 | 76 | 24.44 | 1094.9 |
| -30 | -34.44 | 864.0 | 24 | -4.44 | 982.2 | 78 | 25.56 | 1099.1 |
| -28 | -33.33 | 868.3 | 26 | -3.33 | 986.4 | 80 | 26.67 | 1103.4 |
| -26 | -32.22 | 872.6 | 28 | -2.22 | 990.7 | 82 | 27.78 | 1107.6 |
| -24 | -31.11 | 876.8 | 30 | -1.11 | 994.9 | 84 | 28.89 | 1111.9 |
| -22 | -30.00 | 881.1 | 32 | 0.00 | 1000.0 | 86 | 30.00 | 1116.1 |
| -20 | -28.89 | 885.4 | 34 | 1.11 | 1004.3 | 88 | 31.11 | 1120.4 |
| -18 | -27.78 | 889.6 | 36 | 2.22 | 1008.5 | 90 | 32.22 | 1124.7 |
| -16 | -26.67 | 893.9 | 38 | 3.33 | 1012.8 | 92 | 33.33 | 1128.9 |
| -14 | -25.56 | 898.1 | 40 | 4.44 | 1017.1 | 94 | 34.44 | 1133.2 |
| -12 | -24.44 | 902.4 | 42 | 5.56 | 1021.3 | 96 | 35.56 | 1137.4 |
| -10 | -23.33 | 906.7 | 44 | 6.67 | 1025.6 | 98 | 36.67 | 1141.7 |
| -8 | -22.22 | 910.9 | 46 | 7.78 | 1029.9 | 100 | 37.78 | 1145.9 |
| -6 | -21.11 | 915.2 | 48 | 8.89 | 1034.1 | 102 | 38.89 | 1150.2 |
| -4 | -20.00 | 919.4 | 50 | 10.00 | 1039.0 | 104 | 40.00 | 1154.4 |
| -2 | -18.89 | 923.7 | 52 | 11.11 | 1043.2 | 106 | 41.11 | 1158.7 |
| 0 | -17.78 | 928.0 | 54 | 12.22 | 1047.5 | 108 | 42.22 | 1163.0 |
| 2 | -16.67 | 932.2 | 56 | 13.33 | 1051.8 | 110 | 43.33 | 1167.2 |
| 4 | -15.56 | 936.5 | 58 | 14.44 | 1056.0 | 112 | 44.44 | 1171.5 |
| 6 | -14.44 | 940.7 | 60 | 15.56 | 1060.3 | 114 | 45.56 | 1175.7 |
| 8 | -13.33 | 945.0 | 62 | 16.67 | 1064.6 | 116 | 46.67 | 1180.0 |
| 10 | -12.22 | 949.3 | 64 | 17.78 | 1068.8 | 118 | 47.78 | 1184.3 |
| 12 | -11.11 | 953.5 | 66 | 18.89 | 1073.1 | 120 | 48.89 | 1188.5 |
| 122 | 50.00 | 1192.8 | 124 | 51.11 | 1197.0 | 176 | 80.00 | 1309.7 |
| 126 | 52.22 | 1201.3 | 128 | 53.33 | 1205.5 | 178 | 81.11 | 1313.9 |
| 130 | 54.44 | 1209.8 | 132 | 55.56 | 1214.0 | 180 | 82.22 | 1318.2 |
| 134 | 56.67 | 1218.3 | 136 | 57.78 | 1222.5 | 182 | 83.33 | 1322.4 |
| 138 | 58.89 | 1226.8 | 140 | 60.00 | 1231.1 | 184 | 84.44 | 1326.7 |
| 142 | 61.11 | 1235.3 | 144 | 62.22 | 1239.6 | 185 | 85.00 | 1328.6 |
| 146 | 63.33 | 1243.8 | 148 | 64.44 | 1248.1 | |||
| 150 | 65.56 | 1252.4 | 152 | 66.67 | 1256.6 | |||
| 154 | 67.78 | 1260.9 | 156 | 68.89 | 1265.1 | |||
| 158 | 70.00 | 1269.4 | 160 | 71.11 | 1273.6 | |||
| 162 | 72.22 | 1277.9 | 164 | 73.33 | 1282.1 | |||
| 166 | 74.44 | 1286.4 | 168 | 75.56 | 1290.6 | |||
| 170 | 76.67 | 1294.9 | 172 | 77.78 | 1299.1 | |||
| 174 | 78.89 | 1303.3 | ||||||
| 140 | 60.00 | 1231.7 | 194 | 90.00 | 1348.6 | 248 | 120.00 | 1465.5 |
| 142 | 61.11 | 1235.9 | 196 | 91.11 | 1352.8 | 250 | 121.11 | 1469.8 |
| 144 | 62.22 | 1240.2 | 198 | 92.22 | 1357.1 | 252 | 122.22 | 1474.0 |
| 146 | 63.33 | 1244.4 | 200 | 93.33 | 1361.3 | 254 | 123.33 | 1478.3 |
| 148 | 64.44 | 1248.7 | 202 | 94.44 | 1365.6 | 256 | 124.44 | 1482.5 |
| 150 | 65.56 | 1252.9 | 204 | 95.56 | 1369.9 | 258 | 125.56 | 1486.8 |
| 152 | 66.67 | 1257.2 | 206 | 96.67 | 1374.1 | 260 | 126.67 | 1491.0 |
| 154 | 67.78 | 1261.4 | 208 | 97.78 | 1378.4 | 262 | 127.78 | 1495.3 |
| 156 | 68.89 | 1265.7 | 210 | 98.89 | 1382.6 | 264 | 128.89 | 1499.5 |
| 158 | 70.00 | 1270.6 | 212 | 100.00 | 1387.5 | 266 | 130.00 | 1504.4 |
| 160 | 71.11 | 1274.8 | 214 | 101.11 | 1391.7 | 268 | 131.11 | 1508.7 |
| 162 | 72.22 | 1279.1 | 216 | 102.22 | 1396.0 | 270 | 132.22 | 1512.9 |
| 164 | 73.33 | 1283.3 | 218 | 103.33 | 1400.2 | 272 | 133.33 | 1517.2 |
| 166 | 74.44 | 1287.6 | 220 | 104.44 | 1404.5 | 274 | 134.44 | 1521.4 |
| 168 | 75.56 | 1291.8 | 222 | 105.56 | 1408.7 | 276 | 135.56 | 1525.7 |
| 170 | 76.67 | 1296.1 | 224 | 106.67 | 1413.0 | 278 | 136.67 | 1529.9 |
| 172 | 77.78 | 1300.3 | 226 | 107.78 | 1417.2 | 280 | 137.78 | 1534.2 |
| 174 | 78.89 | 1304.6 | 228 | 108.89 | 1421.5 | 282 | 138.89 | 1538.4 |
Note: Resistance values are calculated using industry-standard coefficients: IEC 60751 (α = 0.00385) for platinum RTDs and (α = 0.00672) for nickel RTDs. The 1K (375) table uses α = 0.00375. For complete tables covering the full temperature range or other RTD types, please contact BAPI technical support or refer to our downloadable specification sheets.
Need Help Selecting an RTD?
Our technical team can help you choose between standard and Class A RTDs for your application.