Rosemount Analytical Bx438 Specifications

The Model Bx438 sensor is designed to monitor trace
levels of dissolved oxygen in beer and other carbonat­ed beverages. The Bx438 sensor utilizes a robust
membrane, which increases the life of the membrane.
The sensor is designed to withstand significantly more
clean in place (CIP) cycles than other dissolved oxy­gen sensors.

Unique Design: Most dissolved oxygen sensors oper­ate by reduction of oxygen at the surface of the cath­ode. If the cathode is in direct contact with the solu­tion, then interference effects from other substances
may lead to inaccurate readings. The Model Bx438
cathode is covered with a gas permeable membrane.
The oxygen diffusing through the membrane is com­pletely reduced at the cathode, and the current
between anode and cathode is proportional to the oxy­gen content in the sample.

The design for the membrane is the key to achieving
high performance. The Model Bx438 uses a propri­etary membrane material. This thick, steel-meshed­reinforced, double layer membrane enables the sen­sor to withstand high pressures and temperatures
while maintaining high diffusion rates, resulting in sta­ble outputs and fast response times.

Longer Sensor Life/Less Maintenance: Due to the
unique design of the sensor, maintenance is rarely
required. The special double membrane design is less
sensitive to contamination from protein and other foul-

ing agents. The electrode construction guarantees
excellent stability even after numerous sterilization
cycles. Competitive dissolved oxygen sensors require
maintenance after as few as 3-5 cycles. The model
Bx438 sensor lasts through as many as 30-50 cycles.

Minimal Flow Sensitivity: Model Bx438 membrane
material and overall design ensure that the flow rate
has minimal effect on the sensor's measurements.
The unique design also experiences minimal drift in
low flow environments.

Zero Polarization Voltage: Many competitive amper­ometric dissolved oxygen sensors set the polarization
voltage to -670 mV. This set point may lead to offset
readings due to carbon dioxide effects at low oxygen
concentrations. The Model Bx438 sensor uses a zero
polarization voltage setpoint, which results in the most
accurate dissolved oxygen readings.

Total Cost of Ownership Comparison: Many com­petitive amperometric dissolved oxygen sensors
require frequent maintenance, such as membrane
replacement, cathode replacement, and electrolyte
replenishment. The Model Bx438 sensor’s robust
design minimizes the maintenance needed for a sta­ble dissolved oxygen measurement. The cost to main­tain the Model Bx438 sensor will be approximately
one-third the cost required to maintain competitive dis­solved oxygen sensors.

DISSOLVED OXYGEN SENSOR

Model Bx438

• DESIGNED FOR CARBONATED BEVERAGES

• LONGER SENSOR LIFE

• LESS MAINTENANCE REQUIRED

• FAST RESPONSE

•

MINIMAL FLOW SENSITIVITY

• LOWER TOTAL COST OF OWNERSHIP

• MINIMAL CO

2

OFFSETS

Product Data Sheet

PDS 71-Bx438/rev.B
July 2004

Emerson Process Management

Liquid Division

2400 Barranca Parkway
Irvine, CA 92606 USA
Tel: [phone]
Fax: [phone]

http://www.raihome.com

© Rosemount Analytical Inc. 2005

ORDERING INFORMATION

Model Bx438 sensor provides a stable signal even in the harshest conditions. The sensor is designed to operate

in breweries and other beverage plants, and can withstand clean-in-place cycles. The Bx438 comes in two inser­tion lengths, and comes standard with a variopol connector head. It can be used with either an insertion mounting
assembly or a retractable mounting assembly.

MODEL Dissolved Oxygen

Bx438 in Carbonated Beverages Sensor (12 mm Diameter)

PN SERVICING ACCESSORIES

24107-00 Service kit for sensors, including three membranes and o-rings
24108-00 50 ml electrolyte
24109-00 Polarization Module

CODE DESCRIPTION

01 120 mm
02 225 mm

PN MOUNTING ACCESSORIES

9160478 Insertion assembly, 70 mm insertion (use 120 mm sensor)
9160477 Retractable assembly, 70 mm insertion (use 225 mm sensor)

99SQ4870 Flexifit 1 1/2" triclamp adapter

9160484 Service kit for insertion mounting assembly
9160486 Service kit for retractable mounting assembly
9160483 15 degree weld in socket, G 1 1/4 in. thread, 44 mm

PN VARIOPOL CABLE

9120550 Cable, with VP 6.0 cable coaxial connection, 3 m (9.8 ft)
9120564 Cable, with VP 6.0 cable coaxial connection, 5 m (16.4 ft)

SPECIFICATIONS

Temperature: -10 to100 Deg C (14 to 212°C)

Maximum Pressure: 175 psig (12 bar)

Wetted materials: Stainless steel, gold, silicone,

EPDM (FDA approved)

Process Connection: PG 13.5 thread

Sensor Lengths: 120 mm or 225 mm

Sensor output in air: 180 to 400 nA

Response time (Air to CO2): T98< 60 Sec

Temperature Compensation: 22K NTC

Cable Connector: Variopol 6.0

Compatible Mounting Accessory: Insertion or Retractable

Compatible Analyzers: 54eA, Xmt-A, 5081A

Specifications subject to change without notice.

The Retractable Mounting Assembly
can be used with Model Bx438 to
achieve insertion and removal of the
sensor without shutting down the
process.

Model 5081
Transmitter

Model 54e

Analyzer

Model Xmt

Analyzer

Model Bx438

Dissolved Oxygen Sensor

CHOICE OF INSTRUMENTS