UNISENSE OXYGEN MICROOPTODE User manual

OXYGEN MICROOPTODE USER MANUAL

Oxygen MicrOOptOde user Manual
Copyright © 2013 · Unisense A/S
Version August 2013

OXYGEN MICROOPTODE USER MANUAL
UNISENSE A/S

TABLE OF CONTENTS
WARRANTY AND LIABILITY...................................................4
CONGRATULATIONS WITH YOUR NEW PRODUCT! ............................5
Support, ordering, and contact information 5
OVERVIEW ...................................................................7
GETTING STARTED ...........................................................8
unpacking anew microoptode 8
connecting the microoptode 8
MEASUREMENTS............................................................11
handling of microoptodeS 11
interference 12
STORAGE AND MAINTENANCE ..............................................13
Storage 13
cleaning the SenSor 13
APPENDIX: EQUILIBRIUM O2CONCENTRATIONS .............................15

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NOTICE TO PURCHASER
This product is for research use only. Not for use in human diagnostic or
therapeutic procedures.
WARNING
Microsensors have very pointed tips and must be handled with care
to avoid personal injury and only by trained personnel.Unisense A/S
recommends users to attend instruction courses to ensure proper use of
the products.
WARRANTY AND LIABILITY
The oxygen MicroOptode Sensor is covered by a 1 year limited warranty
or 1 million data points (estimated 300 hours of measurements).
Wear-off of dye resulting in reduced signal quality, e.g. from profiling
into biological matrices like sediments,and bend and breakage of the
fiber optic cable is not covered by the warranty.
MicroOptodes are consumables. Unisense will only replace
dysfunctional sensors if they have been tested in accordance with the
instructions in the manual within 14 days of receipt of the sensor(s).
The warranty does not include repair or replacement necessitated by
accident, neglect, misuse, unauthorized repair, or modification of the
product. In no event will Unisense A/S be liable for any direct, indirect,
consequential or incidental damages, including lost profits, or for any
claim by any third party, arising out of the use, the results of use, or the
inability to use this product.
Unisense mechanical and electronic laboratory instruments must
only be used under normal laboratory conditions and a dry and clean
environment. Unisense assumes no liability for damages on laboratory
instruments due to unintended field use or exposure to dust, humidity
or corrosive environments.
REPAIR OR ADJUSTMENT
Sensors and electrodes cannot be repaired. Equipment that is not
covered by the warranty will, if possible, be repaired by Unisense A/S
with appropriate charges paid by the customer. In case of return of
equipment please contact us for return authorization.
For further information please see the document General Terms of Sale
and Delivery of Unisense A/S as well as the manuals for the respective
products.
WARRANTY AND LIABILITY

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suppOrt, Ordering, and cOntact infOrMatiOn
The Unisense MicroOptode is an oxygen measuring system based
on the latest development within optical fiber technology. Use
the MicroOptode for fast and accurate oxygen measurement in a
broad variety of research applications.
If you wish to order additional products or if you encounter any
problems and need scientific/technical assistance, please do not
hesitate to contact our sales and support team. We will respond to
your inquiry within one working day.
E-mail: [email protected]
Unisense A/S
Tueager 1
DK-8200 Aarhus N, Denmark
Tel: [phone]
Fax: [phone]
Further documentation and support is available at our website
www.unisense.com.
CONGRATULATIONS WITH YOUR NEW PRODUCT!
REPLACEMENT OF MICROOPTODES
Unisense will replace MicroOptodes that have been damaged during shipment provided that:
• The MicroOptodes were tested immediately upon receipt in accordance with the delivery
note and the manual.
• The white seal is still intact
• The MicroOptodes are returned to Unisense for inspection within two weeks
• The MicroOptodes are correctly packed for return to Unisense, in accordance with the
note included in the MicroOptode shipping box.

88
RECOMMENDED METERS
Unisense MicroOptode Meter

999
OVERVIEW
This manual covers all the Unisense MicroOptodes. The
MicroOptode relies on the latest developments within optical fiber
technology utilizing near infrared dyes for improved performance,
high precision, high reliability, low cross-interference and fast
response times.
The MicroOptodes are designed for research applications within
physiology, biotechnology, environmental sciences and related
areas.
meaSuring principle
The very tip of the optical fiber is coated with a specialized
dye that is excitable with red light (610-630 nm). When the
MicroOptode is connected to a Unisense MicroOptode Meter
the dye is excited with sinusoidal modulated red excitation light.
The dye show an oxygen-dependent luminescence in the near
infrared (NIR, 760-790 nm), and by detecting quenching of the
luminescence the oxygen concentration can be determined in the
sample .
WARNING
Unisense
MicroOptodes are
neither intended
nor approved for
use on humans
Measuring principle:
The near infrared dye
shows oxygen dependent
luminescence in the
near infrared (NIR) after
exposure to excitation
light. A) High NIR
emission at low oxygen
concentration and B)
low NIR at high oxygen
concentration.

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WARNING
Do not remove the
seal and protective
plastic tube
before these steps
and calibration
are successfully
completed.
GETTING STARTED
unpacking anew MicrOOptOde
The MicroOptode sensor is shipped in a protective tube with the
optic fiber positioned half exposed in the needle. Please do not
remove the white seal or move the fiber further out of the needle
before the calibration procedure has been successfully completed.
cOnnecting the MicrOOptOde
Remove the black cap from the MicroOptode connector and
remove the red cap from the MicroOptode Meter. Insert the male
fiber plug of the MicroOptode cable into the ST-receptable of
the MicroOptode Meter and turn the bayonet coupling gently
clockwise until the plug is locked firmly.
calibratiOn
Please consult the software manual for instructions on how to
calibrate the MicroOptode in the software.
Calibration of the oxygen MicroOptode sensor is performed as a
two-point-calibration by measuring the MicroOptode response
in a solution saturated with oxygen and an anoxic solution.
Remember that a temperature sensor is required for correct
oxygen measurements unless the measurement and calibration is
completed at stable temperature.
oxygen Saturated Solution
Place the MicroOptode in a well-aerated calibration solution
(e.g. by bubbling with air in the Unisense calibration chamber).
The MicroOptode and the connecting male fiber plug.

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After 5 min. of vigorous bubbling turn off the air, follow the
MicroOptode signal and when the signal is stable add the point to
the calibration in the software. This signal is your calibration value
for 100% oxygen saturation at atmospheric partial pressure. Zero
reading
Zero reading
An anoxic solution can be prepared in one of several ways; below
we describe two methods recommended by Unisense:
1. Prepare a solution of sodium ascorbate
and NaOH, both to nal concentrations of
0 .1M (~2 g sodium ascorbate in 100 ml of
0 .1M NaOH). This zero calibration solution
can be stored in a closed container for
1-2 weeks. Keep the MicroOptode in its
protective tube and expose only the ber
tip and the needle part of the sensor to the
ascorbic solution, place the MicroOptode
in the anoxic solution, read the signal and
add the point to the software calibration.
Clean the MicroOptode thoroughly in either
tap water or demineralized water to avoid
any carry-over of ascorbic solution to your
sample.
2. Vigorous bubbling with oxygen-free
inert gas (e.g. N2). It is important to apply
vigorous bubbling over a time period (> 5
min.) sucient to ensure that all oxygen has
been removed. Furthermore, it is important
to prevent any contact of oxygen with
the water during bubbling, as oxygen will
otherwise be continuously reintroduced to
the water. In practice this means that the
headspace above the water must be closed
except for a hole slightly larger than the
MicroOptode shaft. This eectively prevents
IMPORTANT
Calibration must
be performed after
pre-polarization
when the sensor
signal has
stabilized.
Always use
a calibration
solution with the
same temperature
and salinity as the
sample solution.
IMPORTANT
The O2sensor
signal is sensitive to
temperature, and
the O2solubility
depends on both
salinity and
temperature.

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ambient air from entering the vessel. We
recommend the Unisense calibration
chamber CAL300. Place the MicroOptode in
the anoxic solution, read the signal and add
the point to the software calibration.
Place the MicroOptode in the anoxic solution. The signal reading
is the calibration value for zero oxygen partial pressure (S0). The
value should be less than 10% of the signal for atmospheric
saturation (otherwise see ‘Troubleshooting’).
When the calibration procedure has been successfully
complete, test that the MicroOptode responses as expected by
inserting it in oxygen saturated solution and anoxic solution.
If the MicroOptode meets these requirements the white seal
can be removed.
CALIBRATION
As oxygen
MicroOptodes
respond linearly to
changes in oxygen
concentrations
a two-point
calibration is
sufficient.

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handling Of MicrOOptOdes
The MicroOptode fiber can be either retracted into the needle or
exposed; the flexible design of the MicroOptodes enables optimal
positioning of the optic fiber tip in various samples.
adjuSting the expoSure of the optic fiber
Positioning of the optical fiber is adjusted by loosening the
locking nut on the MicroOptode and pushing the optical fiber
cable towards the plastic shaft. The optical fiber can be pushed
maximally 1 cm out from the needle protection. Tighten the
locking nut after positioning the optical fiber.
mounting of the microoptode
When the optical fiber is exposed Unisense recommends
mounting the MicroOptode in a stabilized setup using the
Unisense lab stand (LS18) and micromanipulator (MM33, MM33-2)
to avoid damages on the MicroOptode.
When the optical fiber is retracted into the needle in protected
position the MicroOptode can be pushed through a relatively
hard surface such as a rubber septum. The optical fiber can then
subsequently be adjusted to the exposed position, when the
needle tip is positioned in the environment.
Please avoid bending of the fiber cable.
MEASUREMENTS
Adjustment of the fiber position.
NOTE:
Avoid bending of
the cable as this
might break the
MicroOptode.

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interference
The oxygen sensitive dye on the optic fiber shows excellent
brightness and their red light excitation significantly reduces stress
in biological systems and interferences caused by autofluores-
cence. The MicroOptodes can be applied in gas phases, aqueous
solutions, ethanol, methanol and isopropanol. Other organic
solvents and gaseous chlorine (Cl2) induce interferences with the
sensor reading. No cross-sensitivity is found for pH 1-14, CO2, CH4,
H2S and any ionic species.

15
stOrage
Store the sensor in the protective plastic tube used for shipping,
and store it in a dry, dark and secure place
cleaning the sensOr
All oxygen MicroOptodes can be cleaned with peroxide (3% H2O2),
soap solution or ethanol and can furthermore be sterilized with
ethylene oxide (EtO).
STORAGE AND MAINTENANCE

16
TROUBLE SHOOTING
If you encounter other problems and need scientific/technical assistance, please contact
[email protected] for online support (we will answer you within one workday)
Problem Drifting signal
Possible cause 1 Can indicate photobleaching of the dye
Solution Recalibration of the MicroOptode
Problem High signal
Possible cause Can occur from too much ambient light
exposed to the MicroOptode
Solution Darken the surroundings
Problem Low signal
Possible cause Broken tip
Solution Replace the MicroOptode

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APPENDIX: EQUILIBRIUM O2CONCENTRATIONS
Detailed tables are available at our web page http://www.unisense.com/support/tables.html
At 20 oC and 1 atm.: 1 µmol O2/l = 0.032 mg O2/l = 0.024 ml O2
Table 1. Equilibrium concentrations of oxygen (µmol O2/litre) at ambient partial pressure of
0.21 atm. in water as a function of temperature and salinity.
‰ /˚C 0.0 5.0 10.0 15.0 20.0 25.0 30.0 35.0 40.0
0.0
456.6 398.9 352.6 314.9 283.9 257.9 235.9 217.0 200.4
2.0
450.4 393.6 348.1 311.1 280.6 255.0 233.3 214.7 198.3
4.0
444.2 388.5 343.7 307.3 277.3 252.1 230.8 212.4 196.3
6.0
438.1 383.3 339.4 303.6 274.0 249.3 228.3 210.2 194.3
8.0
432.1 378.3 335.1 299.9 270.8 246.5 225.8 207.9 192.3
10.0
426.1 373.3 330.8 296.2 267.6 243.7 223.3 205.7 190.3
12.0
420.3 368.4 326.7 292.6 264.5 240.9 220.9 203.6 188.4
14.0
414.5 363.5 322.5 289.1 261.4 238.2 218.5 201.4 186.5
16.0
408.8 358.7 318.4 285.5 258.3 235.5 216.1 199.3 184.6
18.0
403.2 354.0 314.4 282.1 255.3 232.8 213.7 197.2 182.7
20.0
397.7 349.3 310.4 278.6 252.3 230.2 211.4 195.1 180.8
22.0
392.2 344.7 306.5 275.2 249.3 227.6 209.1 193.0 179.0
24.0
386.8 340.2 302.6 271.9 246.4 225.0 206.8 191.0 177.1
26.0
381.5 335.7 298.7 268.5 243.5 222.5 204.5 189.0 175.3
28.0
376.2 331.2 294.9 265.3 240.6 219.9 202.3 187.0 173.5
30.0
371.0 326.9 291.2 262.0 237.8 217.4 200.1 185.0 171.7
32.0
365.9 322.5 287.5 258.8 235.0 215.0 197.9 183.0 170.0
34.0
3609 3183 2839 2557 2322 2125 1957 1811 1682
36.0
355.9 314.1 280.3 252.5 229.5 210.1 193.6 179.2 166.5
38.0
351.0 309.9 276.7 249.5 226.8 207.7 191.4 177.3 164.8
40.0
346.2 305.8 273.2 246.4 224.1 205.4 189.3 175.4 163.1
42.0
341.4 301.8 269.4 243.4 221.5 203.1 187.3 173.6 161.5
Sources:
Garcia, H.E. and Gordon, L.I. 1992. Limnol. Oceanogr. 37:1307-1312
Millero, F.J. and Poisson A. 1981. Deep Sea Res. 28A:625-629)

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