Rosemount 755, Инструкция по эксплуатации

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M
ODEL
755 O
XYGEN
A
NALYZER
5-6
748183-H
Rosemount Analytical December 1997
Do not subject the sensing unit to an absolute pressure of less than 600
mm Hg (88.1 kPa)
Operation at negative gauge pressure is not normally recommended. but is used in
certain special applications, see Section 2.6.4.
5.2.2 T
EMPERATURE
E
FFECTS
Magnetic susceptibilities and partial pressures of gases vary with temperature. In the
Model 755, temperature-induced readout error is avoided by control of temperatures in
the following areas:
1. Interior of the analyzer is maintained at 140
°
F (60
°
C) by an electrically controlled
heater and associated fan.
2. Immediately downstream from the inlet port, prior to entry into the detector, the
sample is preheated by passage through a coil maintained at approximately the
same temperature as the detector, see Figure 5-3A.
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. During initial installation of an instrument in a given
application, effects of the background gas should be calculated to determine if
correction is required, refer to Section 3.3.
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
Use reasonable precautions to avoid excessive vibration. In making electrical
connections, do not allow any cable to touch the shock-mounted detector 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
could cause noisy readout.
CAUTION: PRESSURE LIMITS