A59440 AA
July 2008
Beckman Coulter Dissolved Oxygen Probe
A57199
How the Dissolved Oxygen Probe Works
The Beckman Coulter Dissolved Oxygen (DO) Probe is a
galvanic electrochemistry device and does not require
power from the meter or controller to generate its signal.
The DO probe will provide a millivolt signal proportional to
the concentration of oxygen in the water. A DO probe does
not measure oxygen directly. It measures the partial
pressure of oxygen in the water, which is directly
proportional to the percentage of oxygen saturation in the
water. The concentration (mg/L or ppm) can be calculated
based upon the oxygen solubility, temperature, salinity, and
total atmospheric pressure.
The DO probe consists of a cathode, anode, and electrolyte
separated from your process fluid by an oxygen-permeable
membrane. The oxygen passing through the membrane
reacts with the cathode, giving up electrons, which produces
an electrical current.
Reconditioning the Probe
1. Remove the pre-membraned cap from the tip of the probe
by turning it counterclockwise and discard, as shown in
Figure 1a.
2. Open the tip on the bottle of DO electrolyte solution. Place
the needle on the plastic bottle, as shown in Figure 1b.
3. Insert the needle into one of the four holes surrounding
the silver cathode. Squeeze the bottle to inject the solution until it leaks out of a fill hole, as shown in Figure 1c.
4. Replace the cap on the probe.
Figure 1. Reconditioning the Probe
b
a
c
Inject until
solution leaks
out of fill hole
(approx. 5 mL)
Calibrating the Probe
The simplest method to calibrate the Dissolved Oxygen
probe is in saturated air. If the water is air saturated, the
partial pressure of air in the water will be the same as it is in
air. Therefore, the millivolt output of the DO probe in air
corresponds to 100% saturation in water. Be sure to remove
water drops from membrane when calibrating in air.
To calibrate the DO probe in line, bubble oxygen or air into
your process fluid to oxygen saturate the fluid. The millivolt
output of the DO probe under these conditions will
correspond to 100% saturation.
If a two-point calibration is needed, a saturated solution of
sodium sulfite will provide a zero oxygen environment. The
DO probe will take several minutes to reach zero millivolts
after it is submerged into the saturated sodium sulfite.
Please see the calibration instructions in the meter user’s
guide for additional details.
©2008 Beckman Coulter, Inc.
4300 North Harbor Boulevard, Fullerton, CA92834-3100
Printed in USA.
Turn counterclockwise to
remove cap
Storing the Probe
If long-term storage of the DO probe is required, remove the
pre-membraned cap and probe, leaving only a little solution
on the membrane to keep it wet. Leaving a full volume of
electrolyte in the DO probe long-term without use will
deplete the anode.
See the Reconditioning the Probe section for instructions on
how to open and close the probe housing.
Probe Specifications
Output at 100% saturation:
36-54 mV
Output at 0% saturation:
<1 mV
Temperature Range:
Maximum 50°C
Minimum 0°C
Accuracy:
± 2% when measuring
temp. equal to cal temp.
Response time:
5 minutes to reach 95%
of final reading
Water flow rate:
Wetted Materials:
Body
Membrane
Min. 2 in./sec. across
membrane
WARNING
Always follow laboratory safety procedures, including
wearing protective gloves and eye wear. Avoid consuming,
inhaling, or coming into direct contact with chemicals or
solutions.
警告
始终按照实验室安全程序操作，包括佩戴防护手套和
眼罩。避免吞食、吸入或直接接触化学物质或溶液。
NOTE
Epoxy
HDPE
Dissolved Oxygen Probe and Accessories
A57199
Dissolved Oxygen Probe
A58726
Dissolved Oxygen Refill Solution
A58728
Replacement Cap with Membrane
If you experience problems with your Beckman Coulter
electrode that these procedures cannot resolve, call your
local Beckman dealer. In the U.S., please call the toll-free
Product Support line at (800) 742-2345.
NOTE
For MSDS information, please visit
www.beckmancoulter.com. Click on customer support,
then MSDS.
NOTE
Please visit www.beckmancoulter.com for a complete list of
electrochemistry meters, electrodes, and accessories.