Bulletin TI-72730J
Installation, Operation and Maintenance Manual
72-730 and 72-O730NA Oxygen Analyzer
www.labgasgenerators.com
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1-800-343-4048
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1
CAUTION: The Balston 72-730 and 72-O2730NA
Oxygen Analyzers will not provide accu-
rate readings unless calibrated on a regular basis.
The procedure for the two point calibration
method is as follows:
1
Isolate the 72-730 and 72-O2730NA by closing the valve between the process stream and
the analyzer (see Figure 4). Attach zero gas to port inlet.
2
Open the valve in the line from the tank of zero gas to the analyzer (gas pressure should be
approximately equal to process pressure, if possible).
3
Allow the zero gas to flow through the analyzer until the reading on the oxygen concentration
display stabilizes.
4
Adjust the zero potentiometer until the oxygen concentration display reads zero.
5
Disconnect the zero gas from the calibration gas line, and connect a tank of span gas (pro-
cess pressure) or a source of clean compressed air.
6
Allow the reading to stabilize, and adjust the span potentiometer until the reading on the oxy-
gen concentration display reads the known percent (span gas) or 20.9% (compressed air).
7
Close the valve from the calibration gas line and re-open the valve between the process
stream and the analyzer.
The procedure for the
single point calibration
method
is as follows:
1
Isolate the 72-730 and 72-O2730NA by closing the valve between the process stream and
the analyzer.
2
Connect a tank of span gas (process pressure) or a source of clean compressed air to the
calibration gas line.
3
Open the valve in the calibration gas line to introduce the span gas or compressed air to the
analyzer.
4
Allow the gas or air to flow through the analyzer until the reading on the oxygen concentra-
tion display stabilizes.
5
Adjust the span potentiometer until the reading on the oxygen concentration display reads
the known percent (span gas) or 20.9% (compressed air).
6
Close the valve from the calibration gas line and re-open the valve between the process
stream and the analyzer.
(
Note:
Parker recommends the use of a span gas with an oxygen content between 1% and
10%.)
The high and low limits of the integral alarm may be set anywhere between 0.5% and 25%
oxygen, depending on the process limitations. To set the high alarm set point, press the alarm
set switch upward and simultaneously adjust the high potentiometer until the meter shows the
desired high alarm set point. To set the low alarm set point, press the alarm set switch downward
and simultaneously adjust the low potentiometer until the meter shows the desired low alarm set
point.
The Balston 72-730 and 72-O2730NA Oxygen Analyzers also include high and low alarm relay
contacts located on the right side panel (see Figure 5). The oxygen analyzer, through the use
of the alarm relay contacts, may be used to control the process stream or remotely activate an
alarm. For example, a high or low oxygen concentration could signal a remote alarm, open a
backup supply of the process stream, or close the process down for protection of downstream
equipment or processes. The alarm relay contacts should be wired (by a qualified electrician).
Both the high and low oxygen alarm conditions are provided with three relay outputs: a common
(C), a normally open (NO), and normally closed (NC).
The relay contacts are rated for 250 VAC, 5 amps resistive or 1 amp inductive load or
24 VDC 5 amps resistive or 1 amp inductive load. Do not exceed these values in order to
maintain the instrument safety certification.
To eliminate the possibility of electrical shock, disconnect the power cord before wiring the
alarm relay contacts to outside circuitry.
Alarm set points
Alarm relay contacts