Infrared Temperature Sensors

Infrared temperature sensors measure the temperature of a surface without being in contact with the surface.  IR temperature sensors measure the infrared energy emitted from an object and then correlate that energy to the surface temperature.  In addition to being useful as non-contact temperature sensors there are models that have very fast response times as well as models that can measure the temperature of very small objects.  Here are some IR sensor characteristics which should be considered when choosing an IR sensor.

• Spot Size: The measurement area is determined by the Field of View of the Sensor (also referred to as the Sensor Optics).   Distance from the target also impacts the spot size.
• Spectral Response: Sensors with general purpose spectral range (~ 7 to 14 microns) may be used for most surfaces other than reflective metal surfaces.  Reflective metal surfaces normally require a device with short spectral response (~2 microns).
• Output: Sensors with a variety of outputs such as 4-20mA, 0-5/10Vdc, thermocouple, USB and RS485 are available.
• Power: Sensors are normally powered by DC voltages but there is a class of sensors known as infrared thermocouples that are self-powered.
• Other Features: Features such as integral display, data logging and alarms are available.