Description And Specifications; Features And Applications - Emerson ROSEMOUNT 5081-A Instruction Manual

MODEL 5081-A
• MEASuRES dissolved oxygen (ppm and ppb level), free chlo-
rine, total chlorine, and ozone.
• SECoNd INPut FoR pH SENSoR ALLoWS AutoMAtIC pH
CoRRECtIoN for free chlorine measurement. No expensive
reagents needed.
• AutoMAtIC BuFFER RECoGNItIoN for pH calibration.
• RoBuSt tYPE 4X ENCLoSuRE protects the transmitter from
hostile environments.
• uSES F
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1.1 FEATURES AND APPLICATIONS

the 5081-A transmitter with the appropriate sensor
measures dissolved oxygen (ppm and ppb level), free
chlorine, total chlorine, and ozone in a variety of
process liquids. the transmitter is compatible with
Rosemount Analytical 499A amperometric sensors for
oxygen, chlorine, and ozone; and with Hx438 and
Gx448 steam-sterilizable oxygen sensors.
For free chlorine measurements, both automatic and
manual pH correction are available. pH correction is
necessary because amperometric chlorine sensors
respond only to hypochlorous acid, not free chlorine,
which is the sum of hypochlorous acid and hypochlo-
rite ion. to measure free chlorine,most competing
instruments require an acidified sample. Acid lowers
the pH and converts hypochlorite ion to hypochlorous
acid. the Model 5081-A eliminates the need for
messy and expensive sample conditioning by using
the sample pH to correct the chlorine sensor signal. If
the pH is relatively constant, a fixed pH correction can
be used. If the pH is greater than 7.0 and fluctuates
more than about 0.2 units, continuous measurement
of pH and automatic pH correction is necessary.
Corrections are valid to pH 9.5.
the transmitter fully compensates oxygen, ozone, free
chlorine, and total chlorine readings for changes in
membrane permeability caused by temperature
changes.

DESCRIPTION AND SPECIFICATIONS

®
FIELdBuS
SECTION 1.0
dIGItAL CoMMuNICAtIoNS.
For pH measurements — pH is available with free
chlorine only — the 5081-A features automatic buffer
recognition and stabilization check. Buffer pH and
temperature data for commonly used buffers are
stored in the analyzer. Glass impedance diagnostics
warn the user of an aging or failed pH sensor.
data are displayed in 0.8 in. (20 mm) high seven-seg-
ment numerals. pH (chlorine only) and temperature
appear in 0.3 inch (7 mm) high digits.
the transmitter has a rugged, weatherproof, corro-
sion-resistant enclosure (type 4X and IP65) of epoxy-
painted aluminum. the enclosure also meets
explosion-proof standards.
the transmitter uses F
communication. digital communications allows
access to AMS (Asset Management Solutions). use
AMS to set up and configure the transmitter, read
process variables, and troubleshoot problems from a
personal computer anywhere in the plant.
A handheld infrared remote controller or the 375 or
475 communicator can also be used for programming.
® F
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DESCRIPTION AND SPECIFICATIONS
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is a registered trademark of Fieldbus Foundation.
SECTION 1.0
Fieldbus digital
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