Emissivity Of Plastic Sheet

A range of emissivity values is usually given for many materials whose emissivity can be affected by surface roughness or finish.

Emissivity of plastic sheet. A diversity of applications from electrical inspections thermal environmental studies to building roof thermography ir refractory evaluations to inspecting mechanical systems process monitoring and control to equine thermography horse thermography infrared condition monitoring to non destructive testing to research and development from security and surveillance to building diagnostics. The emissivity coefficient ε indicates the radiation of heat from a grey body according the stefan boltzmann law compared with the radiation of heat from a ideal black body with the emissivity coefficient ε 1. To optimize the surface temperature measurement of a material. Black plastic 0 95 enamel 0 90 formica 0 93 frozen soil 0 93 glass 0 92 glass frosted 0 96 gold polished 0 02 ice 0 97 iron hot rolled 0 77 iron oxidized 0 74 iron sheet galvanized burnished 0 23 iron sheet galvanized oxidized 0 28 iron shiny.

Note that the emissivity coefficients for some products varies with the temperature. Emissivity is the measure of an object s ability to emit infrared energy. Additionally thin sheets of material such as plastics may be semi transparent in the infrared and therefore have reduced emissivity. The emissivity coefficient ε for some common materials can be found in the table below.

Emissivity values for common materials. For example a plastic material with emissivity 0 92 has reflectivity 0 08. For example if an object had the potential to emit 100 units of energy but only emits 90 units in the real world then that object would have an emissivity. Surface contamination such as dust oil films or other agents will affect the actual emissivity of your material.

Emissivity can have a value from 0 shiny mirror to 1 0 blackbody. To optimize the surface temperature measurement of a material. A material with an emissivity value of 0 would be considered a perfect thermal mirror. Additionally thin sheets of material such as plastics may be semi transparent in the infrared and therefore have reduced emissivity.

The emissive and reflective behavior of most materials is similar in the visible and infrared regions of the electromagnetic spectrum. Since the emissivity of a material will vary as a function of temperature and surface finish the values in these tables should be used only as a guide for relative or delta measurements. Need the emissivity of different and specific materials. Emitted energy indicates the temperature of the object.

Emissivity values of common materials material emissivity aluminum polished 0 05. If reflectivity increases emissivity must decrease. The emissivity information was determined under ideal conditions. A black body is a material that is a perfect emitter of heat energy and has an emissivity value of 1.

A polished aluminum surface with emissivity 0 12 has reflectivity 0 88.