Teledyne 9700 - Flue gas analysis system - Manual (Page 11)

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Flue Gas Analysis System General Information
TELEDYNE BROWN ENGINEERING
Analytical Instruments
3.2 Optional Features
The following optional features are available with the system.
• Integral Alarm Circuitry
One (Model 326B-1) or two (Model 326B-2) adjustable, full-
scale alarm and/or control circuits are available.
Control over an external circuit is achieved by a relay
whose solenoid coil is operated by an electronic
“comparator” circuit. The switch contacts of the relay
(NC/C/NO) are available for interconnection with customer
circuitry at the terminal strip within the analyzer. The
control point at which the analyzer operates is determined
by the setting of a calibrated dial-equipped potentiometer on
the control panel.
The 0–10% range of the standard Model 326B is directly
related to the decade nature of the turns-counting dial; the
0–5% and 0–2% ranges require a simple extrapolation
exercise to determine the proper dial reading for a given
oxygen level within the limits of their range.
The integral control circuitry can be arranged so the relay is
energized above or below the setpoint. Unless otherwise
specified, the control relay in a single setpoint instrument
(Model 326B-1) will be energized downscale from the set
position: relays in a double setpoint instrument (Model
326B-2) will be energized when the oxygen level is reading
in the scale region-ion between setpoint #1 in the lower
region of the scale) and setpoint #2 (in the upper portion of
the scale). These configurations provide power supply as
well as oxygen alarm information. The relays are arranged
to be in an energized condition when the oxygen
concentration of the sample is in the safe region of the scale.
The form “C” SPDT relay contacts are rated at 3 amperes
(non-inductive).