Curve 40
Curve 40 R/T Specifications
Updated Nov 5, 2026
4168 Avenida de la Plata, Suite 107
Oceanside, California 92056
Phone: 760.509.4468
North Star Sensors Curve 40
R/T Specifications
| °C | Resistance Ratio Rt / R25 | NTC (%/°C) | Point Matched Resistance Mfg. Tol. Adder (±%) | Interchangeable T2A Code ±°C Tol. |
|---|---|---|---|---|
| -50 | 44.1667 | -6.31 | 6.5 | 0.58 |
| -45 | 32.3860 | -6.10 | 5.7 | 0.53 |
| -40 | 23.9829 | -5.91 | 5.0 | 0.49 |
| -35 | 17.9282 | -5.73 | 4.4 | 0.44 |
| -30 | 13.5233 | -5.55 | 3.8 | 0.39 |
| -25 | 10.2890 | -5.38 | 3.3 | 0.34 |
| -20 | 7.89305 | -5.22 | 2.8 | 0.30 |
| -15 | 6.10308 | -5.07 | 2.4 | 0.26 |
| -10 | 4.75493 | -4.92 | 2.0 | 0.23 |
| -5 | 3.73160 | -4.78 | 1.7 | 0.21 |
| 0 | 2.94900 | -4.64 | 1.4 | 0.20 |
| 5 | 2.34621 | -4.51 | 1.1 | 0.20 |
| 10 | 1.87868 | -4.38 | 0.8 | 0.20 |
| 15 | 1.51363 | -4.26 | 0.5 | 0.20 |
| 20 | 1.22679 | -4.14 | 0.3 | 0.20 |
| 25 | 1.00000 | -4.03 | 0.0 | 0.20 |
| 30 | 0.81964 | -3.92 | 0.3 | 0.20 |
| 35 | 0.67537 | -3.82 | 0.5 | 0.20 |
| 40 | 0.55935 | -3.72 | 0.7 | 0.20 |
| 45 | 0.46554 | -3.62 | 0.9 | 0.20 |
| 50 | 0.38930 | -3.53 | 1.2 | 0.20 |
| 55 | 0.32705 | -3.44 | 1.4 | 0.20 |
| 60 | 0.27597 | -3.35 | 1.6 | 0.20 |
| 65 | 0.23387 | -3.27 | 1.8 | 0.20 |
| 70 | 0.19900 | -3.19 | 2.0 | 0.20 |
| 75 | 0.17000 | -3.11 | 2.1 | 0.22 |
| 80 | 0.14579 | -3.04 | 2.3 | 0.24 |
| 85 | 0.12548 | -2.96 | 2.5 | 0.28 |
| 90 | 0.10840 | -2.89 | 2.7 | 0.31 |
| 95 | 0.09396 | -2.82 | 2.8 | 0.36 |
| 100 | 0.08172 | -2.76 | 3.0 | 0.40 |
| 105 | 0.07130 | -2.70 | 3.1 | 0.45 |
| 110 | 0.06241 | -2.63 | 3.3 | 0.49 |
| 115 | 0.05479 | -2.57 | 3.4 | 0.54 |
| 120 | 0.04824 | -2.52 | 3.6 | 0.59 |
| 125 | 0.04260 | -2.46 | 3.7 | 0.65 |
| 130 | 0.03772 | -2.41 | 3.8 | 0.70 |
| 135 | 0.03349 | -2.35 | 4.0 | 0.77 |
| 140 | 0.02981 | -2.30 | 4.1 | 0.83 |
| 145 | 0.02660 | -2.25 | 4.3 | 0.92 |
| 150 | 0.02380 | -2.20 | 4.4 | 1.00 |
Column Heading Definitions:
Resistance Ratio – The ratio of the resistance at temperature “t” to the resistance at 25 °C. To determine the resistance of a thermistor at a temperature point other than 25 °C, multiply the given resistance ratio by the resistance at 25 °C.
NTC – The Negative Temperature Coefficient of resistance is the % change in resistance per change in temperature, expressed in units of −%/°C. To determine the approximate % resistance tolerance of a thermistor at a particular temperature, multiply the given NTC value by the temperature tolerance at that temperature.
Point Matched – For thermistors with a specified tolerance at a single temperature point, the manufacturing tolerance is used to determine the tolerance at other temperature points. Typically, thermistors are specified at 25 °C. To determine the resistance tolerance at another temperature point, add the manufacturing tolerance to the specified point matched tolerance. For example, a thermistor with a ±10 % resistance tolerance at 25 °C has a ±11.4 % tolerance at 0 °C. Point matched thermistors should typically not cycle or operate continuously above 105 °C.
Interchangeable T2A Code – An interchangeable tolerance means that a thermistor has a temperature tolerance specified over a temperature range. For example, a “T2A” code indicates a ±0.2 °C temperature tolerance from 0 °C to 70 °C. Typically, interchangeable thermistors should not cycle or operate continuously above their specified temperature range.