2 measuring metallic targets, 4 measuring transparent materials, 5 measuring wet or icy surfaces – Exergen DX User Manual
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3.2 Measuring Metallic Targets
In general, infrared thermometers can easily measure non-
metallic surfaces because they emit most of their potential
heat. Metallic surfaces, on the other hand, are poor emit-
ters and require special treatment before infrared ther-
mometers can accurately measure their temperature.
Fortunately, that special treatment is simple and can be
easily accomplished by marking the metallic surface you
wish to measure with a non-metallic substance such as a
solid paint marker. Other substances such as grease, oil,
or tape may also be used. It is only necessary to mark an
area slightly larger that the DX nosepiece, when operating
in AECS mode. When operating in MAX or SCAN modes,
mark the appropriate target area for the measuring distance
from the target, based on a 1 to 1 Field of View.
3.3 Optimizing AESC Measurements for
NIST Traceablity
If you look at the DX's nosepiece, you will see that it is real-
ly a small reflective cup with the sensor's window at its
base. When the DX's nosepiece touches the surface of an
object, that reflective cup automatically controls what the
sensor sees by eliminating variables such as target emis-
sivity and extraneous radiation. Patented by Exergen as
the Automatic Emissivity Compensation System (AECS),
this unique design ensures accurate readings every time.
To optimize results, make sure that the nosepiece is flush
with the target when possible, so that the reflective cone
can complete trap out any light or incident radiation from
the environment.
3.4 Measuring Transparent Materials
Although transparent materials pass visible light, many visi-
bly transparent materials are opaque in the infrared and
can be directly measured by the DX.
To test for infrared transparency, touch the DX to the tar-
get's surface and pass a heat source such as your hand or
a penlight through the sensor's field of view on the other
side of the material. If the DX responds to the heat source,
the material is transparent in the infrared, and requires
marking the surface for proper measurement. Mark the
surface with an opaque non-metallic coating, such as paint
or grease.
Alternatively, place a shiny metallic object, such as alu-
minum foil, behind the transparent material. The shiny
metal will reflect the target's heat back to the DX.
3.5 Measuring Wet or Icy Surfaces
Wet or icy surfaces may interfere with the DX's readings.
Water and other liquids are good targets, but evaporation
lowers their surface temperatures.
Frost forms on a surface at the freezing point of water.
Frozen foods or similar targets will form frost unless the
environment is controlled. If frost forms, the DX will meas-
ure the temperature of the frost instead of the object's tem-
perature.
Melting ice will read slightly higher than 32 °F (0°C)
because the instrument actually measures the air condens-
ing on the ice, a reaction that generates a small amount of
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