What is an NTC EGT Sensor?

In the fields of automotive and industrial measurement, the NTC EGT sensor is another widely utilized tool for monitoring exhaust gas temperatures.

1. Definition and Core Principle

NTC stands for "Negative Temperature Coefficient." Contrary to PTC (Platinum Resistance) sensors, the core characteristic of an NTC sensor is that its resistance value decreases as the temperature increases. When the exhaust gas temperature rises, the resistance of the semiconductor material inside the sensor drops rapidly; this change is sent to a control unit (such as an ECU) and converted into a precise temperature reading.

2. Why Choose NTC Sensors?

Extremely High Sensitivity: NTC sensors are exceptionally sensitive to temperature changes within specific temperature ranges. Even minute fluctuations can be captured through significant changes in resistance.

Fast Response: Thanks to their semiconductor material, NTC sensors typically feature a shorter thermal response time, providing real-time feedback on temperature dynamics.

High Cost-Effectiveness: Compared to PTC (PT200/PT500) sensors that use precious metals like platinum, NTC sensors are more economical while still meeting the requirements of specific operating conditions. They are the preferred choice for many mass-market applications.

3. NTC vs. PTC: What are the Differences?

Direction of Change:  PTC (PT200/PT500): Temperature rises, resistance rises (excellent linearity, suitable for extreme high temperatures).

NTC: Temperature rises, resistance falls (high sensitivity, suitable for specific temperature zones).

Material: PTC uses the precious metal platinum, while NTC typically uses ceramic or polymer semiconductor materials.

4. Application Scenarios

NTC EGT sensors are commonly used to monitor turbocharger status, exhaust after-treatment systems (such as DPF filters), and other industrial pipelines requiring high-sensitivity temperature feedback. By monitoring temperatures at these critical locations, they effectively protect engine components and optimize combustion efficiency.