NTC Temperature Sensor

An **NTC (Negative Temperature Coefficient) sensor** is a type of temperature sensor whose resistance decreases as the temperature increases. This behavior is the opposite of a **PTC (Positive Temperature Coefficient)** sensor, where the resistance increases with temperature. NTC thermistors are commonly used in temperature sensing applications. They are inexpensive, accurate, and widely available. The resistance of an NTC thermistor is inversely related to the temperature, making it easy to calculate the temperature by measuring its resistance.  ## How NTC Sensor Works A common NTC sensor is **NTC 10K 5% 3950**. Those values refers to the specific characteristics of the thermistor, where: • **10K**: The resistance of the thermistor at **25°C** (room temperature) is **10kΩ**. This means that at 25°C, the thermistor will have a resistance of 10,000 ohms. • **5%**: This indicates the **tolerance** of the thermistor’s resistance. A 5% tolerance means that the actual resistance at 25°C can vary by ±5% from the nominal value of 10kΩ. In this case, the resistance could range from 9.5kΩ to 10.5kΩ at 25°C. • **3950**: This is the **Beta value** of the thermistor, which is a constant used to describe the relationship between the temperature and the resistance of the thermistor. The Beta value is used in temperature calculations, and a Beta value of 3950 means that for this thermistor, the resistance at higher temperatures decreases following this specific Beta curve. As temperature increases, the resistance of the **NTC thermistor** decreases. For example, at higher temperatures (e.g., 50°C), the resistance could drop from 10kΩ to a much lower value. The **Beta value** of 3950 helps determine how much the resistance decreases as temperature increases.