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Temperature Sensors Types: 4 Key Technologies You Must Know

Jun 17, 2025

Why Mastering Temperature Sensors Types Is Crucial

Selecting the right temperature sensor type—thermocouple, RTD, thermistor, or IC sensor—can significantly impact accuracy, reliability, and cost across applications from industrial control to IoT and healthcare. This guide provides deeper insight, backed by performance data and technical recommendations, to ensure you make well-informed decisions that align with your design goals.

Core Analysis: Detailed Comparison of the 4 Main Sensor Types

1. Thermocouples (long-tail: “K‑type thermocouple range accuracy”)

Thermocouples consist of two different metals joined at one end, generating millivoltage via the Seebeck effect

Type	Range (°C)	Accuracy	Sensitivity	Best For
K	–200 to +1370	±1.5 °C / 0.4%	~41 µV/°C	High-temperature, OEM, and industrial
J	–210 to +750	±1.5 °C	Similar to K	Reducing atmospheres
T	–250 to +400	±0.5 °C	Higher sensitivity	Cryogenic applications
B/R/S	Up to 1800 °C	Stable but low sensitivity	~10 µV/°C	Process furnaces, metals industry

Pros: Inexpensive, broad temperature range, fast response.
Cons: Non-linear, cold-junction compensation needed, limited precision (~±1 °C)

2. RTDs (long-tail: “Pt100 RTD accuracy stability”)

RTDs use pure platinum wire/film whose resistance increases with temperature following IEC 60751 standards

Element Type	Range (°C)	Accuracy (at 0 °C)	Notes
Thin-film Pt100	–200 to +600	Class B ±0.3 °C	Economical, widely used
Wire-wound Pt100	–200 to +850	Class A ±0.15 °C	Higher accuracy, robust in harsh use
Industrial-grade RTD	–200 to +600	±0.1–0.3 °C	Focusensing: up to 500 °C with media-grade probes ()

Pros: High linearity, stability, and precision.
Cons: Costlier, slower response, wiring complexity (3/4-wire) needed for high accuracy .

3. Thermistors (long-tail: “NTC thermistor resolution accuracy”)

Thermistors are semiconductors with resistance that strongly depends on temperature—especially NTC types

Property	Value
Range	–55 to +150 °C (glass up to +250 °C)
Accuracy	±0.1 to ±0.2 °C (room temp)
Resistance change	Orders of magnitude (e.g., 10 kΩ ➝ 100 Ω)
Self-heating	High—needs careful current design
Note	Use Steinhart–Hart equation for calibration

Pros: High sensitivity, fast response, low cost.
Cons: Non-linear, limited range, self-heating error, fragility .

4. Integrated Circuit (IC) Sensors (long-tail: “MCP9808 accuracy resolution”)

Silicon-based thermometer ICs like DS18B20, TMP36, MCP9808 provide processed outputs

Sensor	Range (°C)	Accuracy	Resolution	Interface
DS18B20	–55 to +125	±0.5 °C	0.0625 °C (1-Wire)	Digital (1-wire) ()
TMP36	–40 to +125	±2 °C	Analog output (10 mV/°C)
MCP9808	–40 to +125	±0.25 °C typ.	0.0625 °C	I²C, SMBus
MCP9808 B/O	High-end applications	±0.5 °C max.	Selectable	Digital I²C

Pros: Simple integration, digital output, often built-in alerts.
Cons: Moderate range, need stable power/PCB layout for analog types .

Engineering Toolbox Comparison Table

Attribute	Thermocouple	RTD	Thermistor	IC Sensor
Cost	Low	High	Low	Low–Mid
Temp Range	Very wide	Wide	Short–Medium	Short–Medium
Accuracy	Medium	High	Medium	High (IC)
Sensitivity	Low	Medium	Very high	Medium
Response Time	Fast	Medium	Fast	Medium
Linearity	Fair	Good	Poor	Excellent
Stability	Fair	Good	Poor	Good
Self-Heating	None	Low	High	Low

User Feedback & Real-World Insights

Reddit users highlight:

“The DS18B20 is factory calibrated to ±0.5 °C. If I needed ambient temp I’d trust it 10/10.”

“I use thermistor + ADS1115 to calibrate probes—super precise meat thermometer without an app.”

However, users warn of counterfeit DS18B20 units showing up to ±0.9 °C error —quality sourcing is key.

Application Guidance & Focusensing Product Fit

Thermocouples: Best for extreme heat or harsh environments. Use K-type, R/S/B for industrial ovens.
RTDs: Ideal for precision control. Choose Pt100 wire-wound probes (3/4-wire); Focusensing offers up to 500 °C models.
Thermistors: Optimal for fast, narrow-range sensing—HVAC, appliances, battery packs.
IC sensors: Pick DS18B20 for easy integration, or premium MCP9808 for high accuracy and alert functions.

Focusensing provides a full sensor lineup + assemblies:

Industrial RTD probes (Pt100/1000), high accuracy
K/J thermocouples, ruggedized
Sealed NTC thermistor probes
PCB-mount DS18B20 / digital ICs