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 100KΩ 
 Temperature sensors 

High-sensitivity NTC thermistor for precise temperature control in HVAC, automotive, and industrial systems.

 Maximum precision
+/- 0,10°K

 Minimum temperature
-55°C

 Maximum temperature
+150°C

 Minimum dimensions
2 x 10

Response time

Fast

 Drift

Low

 Self-warming
Low

Price
Low

What is a NTC 100KΩ sensor ?


The NTC 100 kΩ is a thermistor with a high nominal resistance (100,000 Ω at 25 °C).

It is the current standard for modern precision sensors: high stability, low power consumption, and excellent sensitivity between 0 and 80 °C.

Its very high impedance makes it ideal for high-impedance analog input microcontrollers, such as ESP32, STM32, Arduino, or industrial measurement boards.

Operating principle


Like all NTCs, its resistance decreases with temperature according to the exponential law:

R(T) = R₂₅ × e^{β (1/T - 1/T₂₅)}

where:

  • R₂₅ = 100000 Ω 
  • β ≈ 3900 K
  • T in kelvins
  • The equation can be linearized using the β formula or Steinhart–Hart for high-precision measurements.

Technical Specifications


Parameter
Typical value

Nominal resistance (25 °C)

100 000 Ω ±1 %
Constant β 3435–3900 K

Sensitive material

Metallic oxide (Mn, Ni, Co)

Type of case Epoxy / glass / film

Maximum measurement current

0.03 to 0.05 mA

Response time

0.2 to 0.8 s

Linearity

Exponential

Operating temperature

−55 → +150 °C

Lifetime

100,000 thermal cycles

Wiring Configuration


Classically set up in a voltage divider, the NTC 100 kΩ is read through an analog ADC input of the microcontroller.

+Vcc │ [Rfixe] │────► ADC (µC) [NTC 100kΩ] │ GND

Self-warming


Thanks to a nearly zero current, the dissipation remains below 0.01 °C/mW, ensuring excellent accuracy without thermal correction.

Application areas


🧠 Industrial and Environmental Probes

🧱 HVAC, Home Automation, and Smart Thermostats

🩺 Medical Sensors, Thermometers, Incubators

🔋 Embedded Electronics and IoT

⚙️ 3D Printers and Precise Thermal Control


Should I choose a 100KΩ sensor ?

Strengths points

  • 🎯 Optimal sensitivity around ambient temperature
    → The NTC 100 kΩ offers excellent accuracy between 0 and 80 °C, making it the standard choice for HVAC, IoT, and medical systems.
  • 🔋 Very low consumption
    → Its high impedance minimizes the measurement current, ideal for standalone devices powered by batteries or solar energy.
  • 💧 No self-heating
    → With a dissipation < 0.01 °C/mW, it ensures absolute stability even during continuous operation.
100kΩ sensors

Weaknesses points

  • 🧮 Important non-linearity
    → The R/T relationship remains exponential: a software compensation (Steinhart–Hart or table) is essential to achieve a precision < ±0.1 K.
  • 🐢 Light thermal inertia
    →The small mass of the sensor allows for stable measurement but has a slightly slower response time than an NTC of lower value.
  • 🌡️ Reduced accuracy at high temperature
    → Beyond 100 °C, the resistance variation becomes small, limiting the reading resolution.

Useful information

Here is some useful information regarding the 100KΩ sensors.

(NTC 100 kΩ at 25 °C, beta constant = 3950 K)

Temperature (°C) Resistance (Ω) Temperature (°C) Resistance (Ω)
−50 2 494 180 60 29 320
−40 1 580 340 70 22 060
−30 1 016 890 80 16 890
−20 670 820 90 13 020
−10 448 400 100 10 100
0 304 600 110 7 820
10 209 500 120 6 310
20 147 400 130 5 030
25 100 000 140 4 030
30 68 630 150 3 240
40 47 620 160 2 620
50 33 640 170 2 130

💡 Between 0 °C and 100 °C, the resistance decreases by a factor of approximately 30, following the classic exponential law of an NTC β ≈ 3950 K.

Class / Tolerance
Tolerance at 25 °C (R25)
Max error on T° (−40 → +125 °C)
Typical usage
±0,5 % ±500 Ω ±0,05 K Medical instruments / calibrations
±1 % ±1 000 Ω ±0,1 K Precision measurement / industrial sensors
±2 % ±2 000 Ω ±0,2 K Consumer Electronics / HVAC
±3 % ±3 000 Ω ±0,4 K Embedded devices or IoT
🔹 The glass encapsulated models (bead) ensure exceptional stability and a drift of < 0.05 K/year.

Complete equation:

1/T = A + B · ln(R) + C · [ln(R)]³

Typical coefficients for NTC 100 kΩ (β = 3950 K):

  • A = 1.4051 × 10⁻³
  • B = 2.369 × 10⁻⁴
  • C = 1.019 × 10⁻⁷


🔹 Example 1: Temperature from R

R = 68,630 Ω

ln(68630) = 11,14

1/T = 1,4051e−3 + 2,369e−4 (11,14) + 1,019e−7 (11,14)³ = 3,04e−3

T = 1 / 3,04e−3 = 329 K = 56 °C

✅ Measured temperature ≈ 56 °C


🔹 Example 2: Resistance from T

T = 80 °C = 353.15 K

R = R₂₅ · e^(β(1/T − 1/T₂₅))

R = 100000 · e^(3950 × (1/353,15 − 1/298,15)) = 16890 Ω

✅ Expected resistance: ≈ 16.9 kΩ

The NTC 100 kΩ is the most common in analog reading circuits.

Its high impedance makes it perfectly compatible with the 12–24 bit ADCs of modern microcontrollers.

🔹 Typical components

Component
Function
NTC 100 kΩ Temperature sensor
R fixed (100 kΩ)
Reference resistance
Microcontroller (ADC)
Analog Lecture
100 nF capacitor
Filtering
Power Supply 3.3 / 5 V
Tension stable
🔹 Functional diagram (ASCII)

+3.3V / +5V │ [Rfixe] │────► ADC (microcontroller input) [NTC 100kΩ] │ GND

💡 The NTC 100 kΩ is currently the most versatile sensor: low cost, great compatibility, and exceptional accuracy around ambient temperature.

More than 1,000,000 probes delivered in 2025

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