Rosemount 755A, Инструкция по эксплуатации

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U
NPACKING AND
I
NSTALLATION
2-8
April 2000 Rosemount Analytical 245364-U Model 755A Oxygen Analyzer
CAUTION: PRESSURE LIMIT
2.5 CALIBRATION GASES
2.5.1 Z
ERO
C
ALIBRATION
G
AS
Zero-based range - Normally uses a oxygen-free gas, typically nitrogen.
Zero-suppressed range - Uses a blend consisting of a suitable percentage of oxygen
contained in a background gas, typically nitrogen.
2.5.2 D
OWNSCALE
S
TANDARD
G
AS
Digital Display - Typically, although not necessarily, the downscale standard gas will
be oxygen-free, such as nitrogen.
Recorder Readout - The downscale standard gas is selected to establish a
calibration point at or near the lower range limit.
2.5.3 U
PSCALE
S
TANDARD
G
AS
Digital Display - Typically, the upscale standard gas will be a readily obtained gas
such as dry air (20.93% oxygen) or 1005 oxygen.
Recorder Readout - A suitable upscale standard gas is required to establish a
calibration point at or near the upper range limit. If this range limit is 21% or
somewhat above 21%, the usual standard gas is dry air (20.93% oxygen).
2.6 SAMPLE HANDLING
Under no circumstances allow pressure to exceed 10 psig (69 kPa) as
irreparable damage to the detector may result.
Many different sample handling systems are available, depending on the requirements
of the individual user. Most sample handling systems have copper or brass
components; however, stainless steel components are available for applications
involving corrosive gases. With corrosive gases, complete drying of the sample is
desirable, as most of these gases are practically inert when totally dry.
For specific corrosive applications, consult the factory.
2.6.1 S
AMPLE
T
EMPERATURE
R
EQUIREMENTS
Sample temperature at the analyzer inlet should be in the range of 50
°
V to 150
°
F
(10
°
C to 66
°
C). With a thoroughly dry sample, entry temperature can be as high as
150
°
F (66
°
C) without affecting readout accuracy. Normally, a maximum entry
temperature of 110
°
F (43
°
C) is recommended so that the sample temperature will rise