|Temperature Sensor are the instruments which measures the temperature . A temperature sensor is a device that measures temperature and is more commonly known as a thermometer. Thermometers rely on a variety of specific mechanisms but one of the simplest types is a fluid thermometer. Fluid generally expands as it gets hotter and this expansion may be measured to determine the temperature. You can make a simple fluid thermometer from common household items.
There are several types of temperature sensors available, some of them include, Thermocouples, Thermistors. Some of them can sense the changes in the temperature when they are distances away. They use the plank law to measure temperatures, which deals with amount of thermal radiation released by a heat source. By using these radiations one can determine the temperatures.