Emerson Oxymitter 5000 Instruction Manual Download

Page: 26 / 226

Oxymitter 5000

1-4

Instruction Manual

IM-106-350, Rev 2.2

July 2008

When the cell is at operating temperature and there are unequal oxygen
concentrations across the cell, oxygen ions will travel from the high oxygen
partial pressure side to the low oxygen partial pressure side of the cell. The
resulting logarithmic output voltage is approximately 50 mV per decade. The
output is proportional to the inverse logarithm of the oxygen concentration.
Therefore, the output signal increases as the oxygen concentration of the
sample gas decreases. This characteristic enables the Oxymitter 5000 to
provide exceptional sensitivity at low oxygen concentrations.

The Oxymitter 5000 measures net oxygen concentration in the presence of all
the products of combustion, including water vapor. Therefore, it may be
considered an analysis on a "wet" basis. In comparison with older methods,
such as the portable apparatus, which provides an analysis on a "dry" gas
basis, the "wet" analysis will, in general, indicate a lower percentage of
oxygen. The difference will be proportional to the water content of the
sampled gas stream.

System Configuration

Oxymitter 5000 units are available in seven length options, giving the user the
flexibility to use an in situ penetration appropriate to the size of the stack or
duct. The options on length are 18 in. (457 mm), 3 ft (0,91 m), 6 ft (1,83 m),
9 ft (2,7 m), 12 ft (3,66 m), 15 ft (4,57 m), and 18 ft (5,49 m).

The integral electronics control probe temperature and provide an output that
represents the measured oxygen concentration. The power supply can accept
voltages of 90-250VAC and 50/60 Hz; therefore no setup procedures are
required. The oxygen sensing cell is maintained at a constant temperature by
modulating the duty cycle of the probe heater portion of the integral electron-
ics. The integral electronics accepts millivolt signals generated by the sensing
cell and produces the outputs to be used by remotely connected devices. The
output is a FOUNDATION fieldbus digital communication signal.

The Oxymitter 5000 transmitter is available with an integral or remote elec-
tronics package. Two calibration gas sequencers are available: the IMPS
4000 and the SPS 4001B (Figure 1-2).

Systems with multiprobe applications may employ an optional IMPS 4000
Intelligent Multiprobe Test Gas Sequencer. The IMPS 4000 provides auto-
matic calibration gas sequencing for up to four Oxymitter 5000 units and
accommodates autocalibrations based on the CALIBRATION RECOM-
MENDED signal from the Oxymitter 5000, a timed interval set up via fieldbus
or the IMPS 4000, or when a calibration request is initiated.

For systems with one or two Oxymitter 5000 units per combustion process, an
optional SPS 4001B Single Probe Autocalibration Sequencer can be used
with each Oxymitter 5000 to provide automatic calibration gas sequencing.
The SPS 4001B is fully enclosed in a NEMA cabinet suited for wall-mounting.
The sequencer performs autocalibrations based on the CALIBRATION REC-
OMMENDED signal from the Oxymitter 5000, a timed interval set up in field-
bus, or whenever a calibration request is initiated.