ircon Modline 4, Инструкция по установке и эксплуатации

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2–8
Section 2 — INSTALLATION
2.
8
OPTICAL CHARACTERISTICS
The detector responds to infrared radiation in a
area indicated by the CONE OF VISION in Fig.
2.8. It will measure temperature of objects inside
this cone. It will not measure objects outside the
cone.
The spot size (d) is the diameter of the cone at a
particular separation distance (D). Separation dis-
tance is the distance between the front of the sen-
sor and the target object whose temperature is
being measured. In Fig. 2.8, d
1
and d
2
represent
the spot size at two different distances D
1
and D
2.
Correct temperature measurement requires that
the field of view be filled entirely by the target. Fig.
2.9 illustrates this ideal condition. Good practice is
to make sure that the target surface is at least
twice the spot size at the spacing used. This gives
you a "cushion" for shifts in MODLINE 4 or target
position, and for the small tolerances in true vs. design diameter of the Cone of Vision that are
inherent in all optical pyrometers.
If the target is not larger than the spot size, the
detector will see infrared radiation from other
objects in its field of view as well as the target.
This causes incorrect temperature indications.
d
2
D
2
d
2
D
1
NOTE: See Table 2.2 for details on finding Spot Size at any given SEPARATION Distance.
AXE OPTIQUE
ALIGNE SUR LE CENTRE
DE LA CIBLE
TAILLE DU SPOT
INFERIEURE A LA TAILLE
DE LA CIBLE
FIG. 2.8 – SPOT SIZE VS. SEPARATION DISTANCE
FIG. 2.9 – IDEAL RESOLUTION AND AIMING PROVIDE MAXIMUM MEASUREMENT ACCURACY
TARGET SIZE
MORE THAN TWICE
SPOT SIZE
OPTICAL AXIS
AIMED AT
CENTER OF TARGET