User manual

Appendix
12Appendix
12.1DeterminationofEmissivity
Emissivity is a measure of an object’s ability to absorb and emit
infraredenergy.Itcanhaveavaluebetween0and1.0.Forexamplea
mirror has an emissivity of < 0.1, while the so‐called “Blackbody“
reachesanemissivityvalueof1.0.Ifa higherthanactualemissivity
value
 is set, the output will read low, provided the target
temperature is above its ambient temperature. For example, if you
haveset0.95andtheactualemissivityis0.9,thetemperaturereading
willbelowerthanthetruetemperature.
An object’s emissivity can be determined by one of the following
methods:
1. DeterminetheactualtemperatureofthematerialusinganRTD
(PT100), a thermocouple, or any other suitable contact
temperature method. Next, measure the object’s temperature
and adjust emissivity setting until the correct temperature
valueisreached.Thisisthecorrectemissivityforthemeasured
material.
2. Ifpossible,apply
flatblackpainttoaportionofthesurfaceof
theobject.Theemissivityofthepaintmustbeabove0.98.Next,
measure the temperature of the painted area using an
emissivity settingof0.98.Finally,measure thetemperature of
an adjacent area  on the object and adjust the emissivity
until
thesametemperatureisreached.Thisisthecorrectemissivity
forthemeasuredmaterial.
80 MID