Selecting a Temperature Sensor on Amazon.com
A temperature sensor is used in many scientific, commercial, and industrial applications to measure temperature. Temperature-sensing technology is incorporated into thermostats, thermometers, data loggers, and temperature meters. Temperature sensors transmit readings to temperature controllers that monitor heating and cooling applications or industrial processes requiring a steady temperature. Considerations when choosing a temperature sensor include the temperature range to be measured, the accuracy required by the application, and the resolution of the reading.
Temperature sensors can measure temperature with or without contact. A contact temperature sensor, such as the probe on a digital food thermometer, touches the heat source or substance to be measured. An infrared temperature sensor, such as a handheld thermometer used in heating, ventilation, and air conditioning (HVAC) equipment maintenance, is a noncontact temperature sensor that can measure thermal radiation remotely. Infrared sensors are commonly used in hazardous environments with high temperatures, such as metal or glass processing.
Different types of contact temperature sensors include thermistors, thermocouples, and resistance temperature detectors (RTDs). Thermistors are small electronic resistors made of metals such as platinum or nickel. The resistors conduct electricity that a digital thermometer can convert to a temperature measurement within a narrow range and with relatively accurate results. A thermocouple sensor generates a voltage flow between two conductors. The thermometer converts the voltage flow into a temperature reading. A thermocouple measures temperatures in a wide range when the accuracy is not critical, such as in a kiln or furnace. An RTD sensor measures the resistance of the metal in the sensor to temperature changes. A thermometer with an RTD sensor provides accurate readings in a narrow temperature range.
Devices that incorporate temperature sensors include temperature meters for use in facility maintenance. Data loggers record and monitor temperatures over a period of time and are for use in temperature-sensitive shipments, such as food. Temperature alarms trigger an alarm when the temperature reaches a predefined point. A thermocouple probe is a temperature sensor encased in a stem or a flexible material that attaches to a digital thermometer or temperature meter. The probe can be immersed in liquid, penetrate a substance, or attach to an object to measure its temperature.