The thermistor is a semiconductor thermal sensor whose resistance value changes exponentially with its temperature. The relationship between its resistance and temperature is non-linear. The positive temperature coefficient thermistor (PTC) has a higher resistance value when the temperature is higher. Large, negative temperature coefficient thermistors (NTC) have lower resistance values at higher temperatures, and they all belong to semiconductor devices. The stability and interchangeability of the components are poor. The measurement temperature is generally -40~200℃, and the measurement accuracy and measurement range are not as good as platinum resistance. The packaging technology of the Uster temperature sensor protects the temperature-sensing element well, so that it does not directly contact the measured medium, avoiding or reducing the erosion of harmful media, the erosion and radiation of flame and airflow, and mechanical damage. It is used to fix and support the temperature sensing element of the sensor.
In mild corrosion and general industrial applications, 304 and 316 (316L) are the most widely used stainless steel protective materials.