What are the major types of temperature sensors?
There are four major types: thermocouples, thermistors, resistance temperature detectors (RTDs), and IC types. The IC types include sensors with analog and digital outputs.
Thermocouples are widely used since they're very rugged and inexpensive. Additionally, they come in many styles and cover a very wide temperature range of –200°C to 2000°C. But they feature low sensitivity, low stability, moderate accuracy, slow response, aging and drifting at high temperatures, and nonlinearity. Additionally, they require an external reference.
Thermistors come in a variety of different package types and price points. They're small, easily interchangeable, and highly stable. Moreover, they have very fast response time and high output levels. Yet they're limited to operating up to about 150°C. They have large temperature coefficients (TCs) of 4%/°C. They're nonlinear, and they need an external reference. They're inherently self-heating as well.
RTDs are extremely accurate, and they feature moderate linearity. They're exceptionally stable, and they come in many configurations. But they can only operate up to about 400°C. They also have large TCs, they're expensive (some four to 10 times those of thermocouples), and they need an external reference.
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