Rosemount 755A, Инструкция по эксплуатации

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T
HEORY
5-6
April 2000 Rosemount Analytical 245364-U Model 755A Oxygen Analyzer
1. Interior of the analyzer case is maintained at 140
°
F (60
°
C) by an electronically
controlled heater and associated fan.
2. Immediately downstream from the inlet port, prior to entry into the detector, the
sample is preheated by passing through a coil maintained at approximately the
same temperature as the detector.
3. The detector is maintained at a controlled temperature of 150
°
F (66
°
C).
5.2.3 I
NTERFERENTS
Instrument response to most non-oxygen sample components is comparatively slight
but is not, in all cases, negligible. Table 3-3 lists the readings that would be obtained
with various gases on an instrument previously calibrated with 100% oxygen,
assuming that all gases are admitted at the same pressure.
During initial installation of an instrument for a given application, effects of the
background gas should be calculated to determine if correction is required. See
Section 3.4.2.
5.2.4 V
IBRATION
E
FFECTS
I
NSTRUMENT
D
ESIGN
To minimize vibration effects, the detector/magnet assembly is contained in a shock-
mounted compartment, Figure 1-2.
I
NSTALLATION
Avoid excessive vibration. In making electrical connections, do not allow any cable to
touch the shock-mounted detector/magnet assembly or the associated internal sample
inlet and outlet tubing. This precaution ensures against possible transmission of
mechanical vibration through the cable to the detector, which would cause noisy
readout.
E
LECTRONIC
R
ESPONSE
T
IME
If readout is noisy despite precautions mentioned above, obtain slower electronic
response by counterclockwise adjustment of Response Time Adjust R30 (see Table 3-
1, Figure 3-2).
5.3 ELECTRONIC CIRCUITRY
Electronic circuitry and internal interconnection wiring is shown in the schematic
diagrams and wiring diagram in the rear of this manual. For detailed circuit analysis,
refer to Section 6.
5.3.1 D
ETECTOR
/M
AGNET
A
SSEMBLY
A cross-sectional view of the optical bench and detector assemblies is shown in
Figure 5-3B. Source lamp DS1, powered by a supply circuit on the Case Board