Model 4000 Percent Oxygen Sensor For Measurement In Gas - Emerson Rosemount Analytical HART 5081-A-HT Instruction Manual

MODEL 5081-A-HT

Model 4000 Percent Oxygen Sensor for Measurement in Gas

Description and Specifications
• STABLE, RELIABLE amperometric Oxygen Sensor
• LONG LIFE, LOW MAINTENANCE rechargeable sensor
• ROBUST DESIGN for harsh applications
• RAPID CALIBRATION using ambient air
• COMPATIBLE WITH 5081-A AND 1055 INSTRUMENTS
APPLICATIONS
The Model 4000 sensor is used to monitor percent
oxygen concentrations in gaseous streams. The most
common use is to monitor oxygen headspace concen-
tration for nitrogen blanketing applications. The sen-
sors are also used in other applications where oxygen
levels are controlled and monitored.
FEATURES
The Model 4000 Series Percent Oxygen sensor is a
membrane-covered amperometric sensor. The mem-
brane consists of a gas permeable Teflon ®
brane stretched tightly over a gold cathode. A silver
anode and an electrolyte solution complete the inter-
nal circuit. The sensor body is constructed of
Ryton ®
2
, which can withstand exposure to hydrocar-
bons and other corrosive chemicals.
Gas permeates through the membrane, and the oxy-
gen in the sample is reduced at the cathode. A volt-
age is applied across the cathode and anode,
generating an electrical current that is directly propor-
tional to the oxygen concentration in the sample.
Since the rate of oxygen diffusion through the mem-
brane is temperature dependent, the sensor response
must be corrected for permeability caused by temper-
ature. A Pt 100 RTD in the sensor accurately meas-
ures temperature, and the analyzer automatically
performs the correction.
The sensor is easy to maintain. For calibration simply
expose the sensor to ambient air and press the air
calibration button. The analyzer measures the baro-
metric pressure using an on-board pressure sensor
APPENDIx B
*
and calculates the equilibrium solubility of atmospher-
ic oxygen at the prevailing temperature and pressure.
Replacing the membrane requires no special tools or
fixtures. To replenish the electrolyte solution, unscrew
the fill plug, add the reagent, and replace the plug.
TyPES OF SENSORS:
Rechargeable with a fast response flow assembly —
allows minimum volume gas flow that permits mount-
ing sensor in a flowing gas stream. Sample is supplied
1
mem-
at slightly above atmospheric pressure, flows through
the assembly, and discharges to atmospheric pres-
sure. Internal volume is low to minimize sensor
response time. Refer to Figure 1 for mounting instruc-
tions.
Rechargeable In-line flow — In line pressure com-
pensated flow assembly permits mounting the sensor
in a variable pressure gas stream at pressures up to
50 psig. This may or may not include a gland on the
sensor body. Refer to Figures 2, 3, and 4 for mounting
instructions.
*
RYTON is resistant to 30% sulfuric acid, 85% phosphoric acid,
30% sodium hydroxide, gasoline, aliphatic alcohols, esters, ethers,
and ketones, as well as to aromatic amines. It is not particularly
suited for service in strong oxidizing agents, aliphatic amines, chlo-
rinated hydrocarbons, or aromatic nitrites, aldehydes, and nitro
compounds.
1 Teflon is a registered trademark of E.I. du Pont de Nemours & Co.
2 Ryton is a registered trademark of Chevron Phillips Chemical Company LP.
APPENDIx B
99