ircon Modline 4, Инструкция по установке и эксплуатации

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Section 3 — OPERATION
3–2
TABLE 3.1 – WINDOWS FOR MODLINE 4
SPECTRUM RECOMMENDED WINDOW
SERIES (µm) MATERIAL
1
TRANSMITTANCE
43 3.43 ±0.07 Synthetic Sapphire 0.88
44 or 22 8 to 14 Germanium
2,3
≥
0.90
45 3.7 to 4.0 Synthetic Sapphire 0.88
46 2.0 to 2.6 Fused Quartz
3,4
0.94
47 4.8 to 5.2 Calcium Fluoride 0.94
48 7.5 to 8.5 Calcium Fluoride 0.92
NOTES: 1. Optical grade, 1/8-inch thick, polished to “plate glass” finish.
2. Requires anti-reflection coatings, optimized for 8 to 14 µm, applied to both surfaces. This window is very
expensive and requires careful handling.
3. Do not exceed 1/8-inch thickness or the transmittance will be degraded.
4. Water-free quality. General Electric Type 124 or equivalent.
RECOMMENDED SOURCES:
Bond Optics, P.O. Box 422, Etna Road, Lebanon, New Hampshire 03766
Adolph Meller Optics, P.O. Box 6001, Providence, Rhode Island 02940
Janos Technology Inc., HCR#33, Box 25, Route 35, Townshend, Vermont 05353-7702
Karl Lambrecht Corp., 4204 Lincoln Avenue, Chicago, Illinois 60618
Potential interference and temperature measure-
ment errors in any given measurement situation
are aggravated by a combination of decreasing
target emissivity and decreasing target tempera-
ture compared to surrounding temperatures. At
target temperatures below 400˚F (200˚C), the gen-
eral trend of temperature /emissivity combinations
to be avoided is as follows:
Temperature Avoid Emissivity
Settings Below
350°F/175°C 0.10
300°F/150°C 0.30
250°F/120°C 0.50
200°F/90°C 0.70
150°F/65°C 0.90
IMPORTANT! For Series 43 instruments,
emissivity must be greater than 0.9 for
measurements in which temperature will be less
than 300°F (150°C).
Measurements may be made under these condi-
tions, but special precautions will undoubtedly be
necessary and measurement problems may be
3.4 EFFECT OF WINDOWS ON
EMISSIVITY SETTING
If you view your target through a window, a certain
percentage of the target radiation will be reflected
or absorbed by the window material and will not
reach the MODLINE 4. To compensate for the
window loss,multiply the target emissivity,
ε
T
, by
the transmittance of the window,
τ
W
, and set the
ε
control to this value,
ε
SET.
Example: A target with an emissivity of 0.80 is
viewed through a window with 90% transmittance.
ε
SET
=
ε
T
X
τ
W
= 0.80 X 0.90
= 0.72
Transmittance factors for some commercially avail-
able window materials are given in Table 3.1.
anticipated. If you are operating under these condi-
tions and encounter measurement problems,
contact IRCON Technical Service for advice.