Infrared Thermometers

Compare INFRARED THERMOMETERS. Infrared thermometers detect the infrared emission of a spot some distance from the thermometer. IR thermometers are also known as pyrometers and non-contact thermometers. The optics of the IR thermometer will determine the size of the spot that will be measured at a given distance. The distance to spot ratio is the distance to the object being measured compared to the the size of the measurement area or spot. For example, a ratio of  8:1 means that if the distance to the object is 32 inches, the area of the measurement will a circle with a diameter of  4 inches. The distance from the IR source to the IR thermometer may be a few inches or a few feet. Different infrared thermometers are built to measure at different distances.

IR thermometers are used to measure the temperature of things that would be difficult to measure with conventional thermometers. They use the infrared radiation being emitted by the object to determine the temperature. The emissivity of the object to be measured has to be entered in the infrared thermometer to get an accurate reading. The emissivity is the efficiency a surface radiates IR waves. Perfect radiation has an emissivity of 1.0 and is called a blackbody. When measuring, the temperature emission of a large spot may not be uniform. Many instruments will measure the maximum, minimum and average temperatures of the region. These are called the measuring modes.

In most models it can be entered from the readout which has either three or four LEDs. Memory storage is available on many models as are USB and Ethernet outputs. An important feature that is standard on most infrared thermometers is a laser pointer. This assures that the correct point is measured particularly with instruments with a large spot ratio. The products listed here have technical features that put their price above $1000. Simple IR thermometers starting in the $100 range are available from some of the manufacturers.