PT100 Resistance Chart

PT100 temperature sensors are commonly used platinum resistance sensors in industrial applications within the range of -200°C to 850°C. They measure temperature from the change in platinum resistance, which rises with temperature along the curve defined in IEC 60751. Here, “PT” stands for platinum, and “100” indicates a standard resistance value of 100 Ω at 0°C.

Compared to other temperature sensors (such as thermocouples and NTC thermistors), the PT100 offers high accuracy (Class A: ±0.35 °C at 100 °C), excellent stability, and a nearly linear output. It is widely used in medical equipment, industrial automation, food processing, automotive electronics, and other fields.

To ensure the accuracy of measurement data, it is essential to establish a clear PT100 Resistance Chart. The following section provides a comprehensive reference for practical applications through comparison tables, key usage points, and explanations of common issues.

RFQ

PT100 Calculator: Resistance to Temperature

You’ve measured 120.00 Ω with a multimeter at the test site and want to know what temperature that corresponds to? Use our free PT100 calculator and datasheet generator: convert ohms to Celsius/Fahrenheit, look up tolerance classes, and print or download a custom resistance datasheet based on the IEC 60751 standard.

PT100 Calculator

• Two-way conversion between ohms and °C/°F, supporting PT100, PT500, and PT1000.
• Displays the sensitivity (Ω/°C) at that temperature, as well as tolerance classes AA, A, B, and C (given in both °C and Ω).
• When measuring a two-wire sensor with a multimeter, enter the lead resistance, and the calculator will automatically compensate for it.
• The corresponding row from the resistance chart is displayed below the result for easy cross-referencing with the table.

PT100 Resistance Table Generator

• Customize the temperature range and step size (0.1–10 degrees); units can be selected as °C or °F.
• Select between the IEC 60751 curve (α = 0.00385) or the PT-392 curve (α = 0.00392).
• You can format the output as a 10-column chart or as a list, with the list including dR/dT and tolerance for each temperature point.
• Supports printing, downloading as a CSV file, or one-click copying to Excel.

All values are calculated using the Callendar–Van Dusen formula and coefficients specified in IEC 60751, with an applicable range of -200 to 850 °C.

PT100 Resistance Chart

This PT100 resistance chart gives the resistance in ohms for every 1 °C from −200 to 850 °C. Values are calculated from the IEC 60751:2022 reference equation (ITS-90 coefficients) and rounded to 0.01 Ω.

Find the tens in the left column, then move across to the units column. For example, a PT100 at 126 °C reads 148.33 Ω: row 120, column 6. Below 0 °C the columns count downward, so row −30, column 5 is −35 °C (86.25 Ω).

−200 to 0 °C

0 to 850 °C

For a PT1000, multiply each value by 10. Older tables based on the IPTS-68 temperature scale show slightly lower values above 100 °C, for example, 280.90 Ω instead of 280.98 Ω at 500 °C. Use the generator above to print a custom range or a Fahrenheit table.

Recommended PT100 Sensors and Transmitters

3-wire Pt100 probe for -200 to 600 °C. Probe length, thread and cable length are made to order.

Pt100 and Pt1000 assemblies in Class A (R0 = 100 ± 0.06 Ω) or Class B (± 0.12 Ω), single or dual element, with threaded, flange or explosion-proof mounting.

Converts a Pt100 or thermocouple input to a two-wire 4–20 mA signal, with a local display. Explosion-proof version available.

PT100 Resistance Chart (°F)

In Fahrenheit, a PT100 reads 100.00 Ω at 32 °F and 138.51 Ω at 212 °F. This chart covers −320 to 1560 °F in 10 °F steps, using the same IEC 60751 values as the Celsius table.

Each row spans 100 °F. Find the hundreds in the left column, then move across to the tens. For example, 350 °F is row 300, column 50: 167.24 Ω. Below 0 °F the columns count downward.

Need 1 °F steps? Select °F in the table generator above and print the range you need.

PT100 Formula: Callendar–Van Dusen Equation

IEC 60751 defines PT100 resistance with the Callendar–Van Dusen equation:

• 0 to 850 °C: R(t) = R₀ (1 + A·t + B·t²)
• −200 to 0 °C: R(t) = R₀ [1 + A·t + B·t² + C·(t − 100)·t³]

R₀ = 100 Ω (1000 Ω for a PT1000), A = 3.9083 × 10⁻³, B = −5.775 × 10⁻⁷, C = −4.183 × 10⁻¹².

Example: at 150 °C, R = 100 × (1 + 0.58625 − 0.01299) = 157.33 Ω.

To convert resistance back to temperature above 0 °C, use t = [−A + √(A² − 4B(1 − R/R₀))] ÷ 2B. A reading of 120.00 Ω gives 51.57 °C. Below 0 °C there is no direct solution, so use the calculator above.

The familiar α = 0.00385 is only the average slope from 0 to 100 °C. The real slope drops from 0.391 Ω/°C at 0 °C to 0.345 Ω/°C at 400 °C, so the shortcut “100 + 0.385 × t” works only for rough checks below 100 °C.

Further Reading

Need a PT100 sensor or transmitter with a specific range, tolerance class or wiring? Send us your requirements and our engineers will reply with a recommendation and quote.

Zhang Wei

Zhang Wei, possesses 20 years of experience as an automation instrumentation engineer, specializing in the research, design, installation, commissioning, and maintenance of automation instruments.

Face to various instrument communication protocols (such as Modbus, Profibus, etc.), with solid hardware circuit design and software programming skills (proficient in C language and PLC programming). Has extensive project experience; projects he has led and participated in have all achieved outstanding results, improving product accuracy, reducing costs, and increasing production efficiency.

Possesses excellent communication and coordination skills and a strong team spirit, enabling him to quickly respond to customer needs and provide high-quality automation instrumentation solutions.