ONNLINE DT-8863 Operating Manual page 9

into a temperature reading, which is display on the unit. In
units with a laser, the laser is used for aiming purposes only.
* Field of View
Make sure that the target is larger than the unit's spot size.
The smaller the target, the closer you should be to it. When
accuracy is critical, make sure the target is at least twice as
large as the spot size.
* Distance & Spot Size
As the distance (D) from the object increases, the spot size
(S) of the area measured by the unit becomes larger. See:
Fig: 1.
* Locating a hot Spot
To find a hot spot aim the thermometer outside the area of
interest, then scan across with an up and down motion until
you locate hot spot.
* Reminders
① Not recommended for use in measuring shiny or
polished metal surfaces ( stainless steel, aluminium,
etc.).See Emissivity
② The unit cannot measure through transparent surfaces
such as glass. It will measure the surface temperature of the
glass instead.
③ Steam, dust, smoke, etc., Can prevent accurate
measurement by obstructing the unit's optics.
* Emissivity
Emissivity is a term used to describe the energy-emitting
characteristics of materials.
Most (90% of typical applications) organic materials and
painted or oxidized surfaces have an emissivity of 0.95
(pre-set in the unit). Inaccurate readings will result from
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