Fluke TiS, User Manual

Thermal Imaging Scanner 

Changing the Temperature Units 

 11 

3.

Press the softkey labeled 

All Images

. 

Changing the Temperature Units 

The Imager will display temperature in Fahrenheit or Celsius. To change the 
temperature units: 

1.

Press 



 until 

Units

 is displayed over 



. 

2.

Press the softkey labeled 

Units

. 

3.

Press 



 for Celsius or 



 for Fahrenheit. 

4.

Press the softkey labeled 

Back/Done

 to set the language. 

Making Accurate Temperature Measurements 

All objects radiate infrared energy. The amount of energy radiated is based on 
two primary factors: the surface temperature of the object and the emissivity of 
the object's surface. The Imager detects the infrared energy from an object and 
uses this information to estimate the temperature of the object. Most of the 
objects measured such as painted metal, wood, water, skin, and cloth are very 
efficient at radiating energy and it is easy to get very accurate measurements. 
For surfaces that are efficient at radiating energy (high emissivity), the 
emissivity factor is estimated to be 95 % (or 0.95). This estimate works for 
most purposes. This simplification does not work however, on shiny surfaces 
or unpainted metals. These materials are not efficient at radiating energy and 
are classified as having low emissivity. To accurately measure materials with a 
low emissivity, an emissivity correction is necessary. The easiest correction 
method is to set the Imager to the proper emissivity value so the Imager 
automatically calculates the correct surface temperature. If the Imager uses a 
fixed emissivity value (meaning that it is set to one value and the user cannot 
adjust it), then the Imager’s measurement must be multiplied by a value found 
in a look up table to get a more accurate estimate of the actual temperature. 

The TiS has emissivity that is permanently fixed at 0.95, which works well for 
most surfaces but can provide very inaccurate reading if used directly on a 
shiny metal surface.  

A significant amount of information is available on emissivity. Further study 
of this topic is recommended to get the most accurate temperature 
measurements using the Imager.