Rosemount 755A, Инструкция по эксплуатации

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I
NTRODUCTION
1-2
April 2000 Rosemount Analytical 245364-U Model 755A Oxygen Analyzer
The basic electronic circuitry is incorporated into two master boards: The Control
Board Assembly and the Case Circuit Board Assembly (see Figure 1-2). The Control
Board has a receptacle which accepts optional circuit boards, thus permitting inclusion
of such features as current output.
1.2 OXYGEN RANGE ON FRONT PANEL DIGITAL DISPLAY
The front panel LCD (liquid crystal display) provides direct readout of oxygen
concentration from 0.00% to 100.00%.
1.3 OXYGEN RANGES FOR RECORDER READOUT
If desired, the recorder output may be set for a fullscale range of 0 to 100% oxygen.
Alternatively, a desired portion of this overall range may be selected for fullscale
presentation on the recorder. The selection is made by an appropriate combination of
scale expansion and zero suppression.
S
CALE
E
XPANSION
Fullscale oxygen span for the recorder is switch selectable for 1%, 2%, 5%, 10%,
20%, or 100% oxygen.
Z
ERO
S
UPPRESSION
The desired zero suppression is obtained as the sum of (a) a jumper selectable fixed
value of 0%, 20%, 40%, 60% or 80% oxygen and (b) a continuously adjustable value
of 0% to 25% oxygen. Thus the electronic circuitry provides the capability of setting
the total zero suppression for any desired value from 0% up to a theoretical maximum
of 105% oxygen.
However, the maximum usable zero suppression is 99%, which is used in establishing
a range of 99% to 100%.
The effective zero suppression, in volts, may be read on the digital display by placing
the front panel TEST Switch in position 4 and the Reorder Oxygen Span Selection
Switch in 1 X gain position (i.e., 100% oxygen)
Example:
Desired oxygen range for recorder output: 99% to 100% oxygen.
Required span is 1% oxygen, obtained by jumper position.
Required zero suppression is 99% oxygen. Thus, fixed zero suppression of 80%
oxygen is selected by jumper position, and adjustable zero suppression is set for
19% oxygen.