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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 ?Operating principleTechnical SpecificationsWiring ConfigurationSelf-warmingApplication areas

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 3435–3950 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.

 We integrate any sensor into any probe 

Smooth tube probe

 Smooth tube 

Waterproof probe

 Waterproof

Bayonet probe

 Bayonet

Slot probe

 Slot

Ambient probe

 Atmosphere

Connection head probe

Termal block

Stick-in probe

Stick-in

Thread probe

Thread

Contact probe

Contact

Jacketed probe

Jacketed

PCBA Design

PCBA design

Winding probe

Winding

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