Omega HHF142, Руководство пользователя

Страница: 14 / 30

SECTION 3 - OPERATIONAL NOTES
Caution: Do not attempt to measure flow from a duct that is smaller than the
diameter of the probe head that you are using. This will cause a false reading.
Follow the minimum duct cross-section guidelines as detailed below:
2.75 inch Air Probe:
1 Inch Air Probe:
Minimum duct width of2.7 inches (69 cm)
Minimum duct height of2.7 inches (69 cm)
Minimum duct diameter of 2. 7 inches (69 cm)
Minimum duct width of 1.0 inches (2.7 cm)
Minimum duct height of 1. 0 inches (2.7 cm)
Minimum duct diameter of 1. 0 inches (2.7 cm)
9009 -
Out of Range Error: There are a few circumstances which will cause
the instrument to display
9009,
which is the out-of-range er
r
or. They are:
1. Duct dimension is too small: If one of the user-entered duct
dimensions is smaller than the probe diameter as described above, the
instrument will display the out-of-range error.
2. Duct cross-sectional area is too large: If the cross-sectional area of
the duct is too large, the instrument will not be able to display a
meaningful result. The out-of-range error will be displayed. The
maximum duct cross-sectional areas are as follows:
a. 35 ft
2
(3.25 m
2
)
when displaying in cubic feet per minute
(CFM)
b. 20 ft
2
(1.86 m
2
)
when displaying in cubic meters per hour
(CMH)
3. Volume flow rate is too high: If the calculated volumetric flow rate is
higher than 9999 cubic feet per minute (CFM) or 9999 cubic meters per
hour (CMH) the result cannot be displayed by the instrument. The out­
of-range error is displayed.
Rev 1.9, 10-Jun-2008
Page 13 of28