Less sophisticated models may omit this control and instead rely upon a fixed ε value of 0.95 to 0.97. Many point radiometers have controls that allow a user to input an ε value that is appropriate for the target being measured. For objects with very low emittance values (ε ≤ 0.2), accurate temperature measurement may not be possible. This is because the point radiometer is sensing heat from the object of interest as well as heat from nearby objects that is being reflected from the surface of the target.

Temperature measurement accuracy can be significantly impacted when measuring low emittance objects such as shiny metals. To help ensure measurement accuracy, an emittance value of greater than 0.8 is desired. In general, it is easier to obtain accurate infrared temperature measurements of high emittance targets. Examples of materials with high ε values would include wood, plastics, painted surfaces (other than metallic spray paints), and organic materials. Objects which radiate infrared energy efficiently will have high emittance values while shiny metals will have low emittance values. The amount of infrared energy radiated by a given object is represented by its emittance value (ε) which is represented as a number between 0 and 1. Let’s examine these error sources and how they affect measurement accuracy.Įmittance – It is a fact that all objects above Absolute Zero (0 Kelvin) emit infrared energy. The spot measurement size of the point radiometer.The environment and atmosphere between the point radiometer and target.When using an infrared thermometer, the accuracy of displayed temperature values can be significantly influenced by several factors. This detected infrared energy is then converted to a temperature value that is shown in real-time on the instrument’s display screen. Unlike other types of thermometers, point radiometers sense the normally invisible infrared or heat energy that is naturally emitted from the surface of all objects. Although they are relatively easy to operate, ensuring accuracy requires more than taking a ‘point and shoot’ approach. Portability and instantaneous results are two of the many benefits that these instruments provide. Level III Certified Infrared Thermographer Thermasearch, Inc.Ĥ3 High Point Drive and Mayflower, AR 72106 Ph: 50 radiometers, also known as infrared thermometers, have become a common tool in a variety of workplaces. Level III Certified Infrared Thermographer Infraspection InstituteĤ25 Ellis Street Burlington, NJ 08016 Ph: 60 R. Equipment Use and Performance Standards.

Radiometer point measure