Xylem WTW TriOxmatic 690 User manual

OPERATING MANUAL
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TriOxmatic®690
DISSOLVED OXYGEN SENSOR

TriOxmatic®690
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Copyright © 2020 Xylem Analytics Germany GmbH
Printed in Germany..

TriOxmatic®690 Contents
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TriOxmatic®690 - Contents
1 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
1.1 Structure of the TriOxmatic®690 . . . . . . . . . . . . . . . . . . . 5
1.2 Recommended fields of application . . . . . . . . . . . . . . . . . 5
2 Safety . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
2.1 Safety information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
2.1.1 Safety information in the operating manual . . . . . 6
2.1.2 Safety signs on the product . . . . . . . . . . . . . . . . . 6
2.1.3 Further documents providing safety information . 6
2.2 Safe operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
2.2.1 Authorized use . . . . . . . . . . . . . . . . . . . . . . . . . . 7
2.2.2 Requirements for safe operation . . . . . . . . . . . . . 7
2.2.3 Unauthorized use . . . . . . . . . . . . . . . . . . . . . . . . 7
3 Commissioning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
3.1 Scope of delivery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
3.2 Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
3.3 Commissioning / Getting the instrument ready for
measuring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
4 Measuring / Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
4.1 Measuring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
4.2 Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
4.2.1 General information on calibration . . . . . . . . . . . 9
4.2.2 Calibration in water vapor-saturated air . . . . . . 10
4.3 Function check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
5 Maintenance, cleaning, disposal, and replacement . . 13
5.1 General maintenance instructions . . . . . . . . . . . . . . . . . 13
5.2 Cleaning the sensor shaft and membrane . . . . . . . . . . . 13
5.3 Changing the electrolyte and membrane cap . . . . . . . . 16
5.4 Cleaning the electrodes . . . . . . . . . . . . . . . . . . . . . . . . . 20
5.4.1 Cleaning the gold working electrode . . . . . . . . . 22
5.4.2 Cleaning the silver counter electrode . . . . . . . . 23
5.5 Checking the sensor for freedom from zero-current . . . 29
5.6 Storage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
5.7 Disposal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

Contents TriOxmatic®690
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5.8 Maintenance equipment and replacement parts . . . . . . . 31
6 What to do if... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
7 Technical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
7.1 General data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
7.2 Measurement conditions . . . . . . . . . . . . . . . . . . . . . . . . . 36
7.3 Characteristic data on delivery . . . . . . . . . . . . . . . . . . . . 37
7.4 Electrical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

TriOxmatic®690 Overview
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1Overview
1.1 Structure of the TriOxmatic®690
Fig. 1-1 Structure of the D. O. sensor
1.2 Recommended fields of application
Stationary measurements in water/wastewater applications.
1Protective hood
2WP 600 membrane cap
3Electrode unit
4Shaft
Electrode unit:
5Gold working electrode (cathode)
6Insulator
7Silver counter electrode (anode)
8Reference electrode
334
6
5
78
2
1

Safety TriOxmatic®690
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2Safety
2.1 Safety information
2.1.1 Safety information in the operating manual
This operating manual provides important information on the safe oper-
ation of the product. Read this operating manual thoroughly and make
yourself familiar with the product before putting it into operation or
working with it. The operating manual must be kept in the vicinity of the
product so you can always find the information you need.
Important safety instructions are highlighted in this operating manual.
They are indicated by the warning symbol (triangle) in the left column.
The signal word (e.g. "CAUTION") indicates the level of danger:
WARNING
indicates a possibly dangerous situation that can lead to serious
(irreversible) injury or death if the safety instruction is not fol-
lowed.
CAUTION
indicates a possibly dangerous situation that can lead to slight
(reversible) injury if the safety instruction is not followed.
NOTE
indicates a situation where goods might be damaged if the actions
mentioned are not taken.
2.1.2 Safety signs on the product
Note all labels, information signs and safety symbols on the product. A
warning symbol (triangle) without text refers to safety information in this
operating manual.
2.1.3 Further documents providing safety information
The following documents provide additional information, which you
should observe for your safety when working with the measuring sys-
tem:
Operating manuals of other components of the measuring system
(Power supply units, controllers, TriOxmatic®690, accessories)
Safety datasheets of calibration and maintenance equipment (e.g.

TriOxmatic®690 Safety
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cleaning solutions).
2.2 Safe operation
2.2.1 Authorized use
The authorized use of the TriOxmatic®690 consists of its use as a sen-
sor in the TriOxmatic®690.The authorized use of the TriOxmatic®690
consists of its use as a sensor in the TriOxmatic®690. Only the opera-
tion and running of the sensor according to the instructions and techni-
cal specifications given in this operating manual is authorized (see
chapter 7 TECHNICAL DATA). Any other use is considered unauthorized.
2.2.2 Requirements for safe operation
Note the following points for safe operation:
The product may only be operated according to the authorized use
specified above.
The product may only be supplied with power by the energy sources
mentioned in this operating manual.
The product may only be operated under the environmental condi-
tions mentioned in this operating manual.
The product may not be opened.
2.2.3 Unauthorized use
The product must not be put into operation if:
it is visibly damaged (e.g. after being transported)
it was stored under adverse conditions for a lengthy period of time
(storing conditions, see chapter 7 TECHNICAL DATA).

Commissioning TriOxmatic®690
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3 Commissioning
3.1 Scope of delivery
TriOxmatic®690
The sensor is filled with electrolyte and provided with a protective
hood and protective caps.
ZBK 600 accessory kit
Operating manual.
3.2 Installation
Connection to the
measuring transmitter
The TriOxmatic®690 connection cable has a screw plug to be
connected to the Oxi input socket of a measuring transmitter. It is
connected to the terminal strip of measuring transmitters without an Oxi
input socket via the ADA/AMPH adapter. For detailed information
please refer to the operating manual of the measuring transmitter.
3.3 Commissioning / Getting the instrument ready for
measuring
Precision
measurements
Recommendation: In order to carry out precision measurements, leave
the sensor to polarize for a longer period of time, e.g. overnight, and
recalibrate it the following day.
Do not suspend the sensor on the sensor connection cable.
Use a sensor holder or armature. Information on this and
other TriOxmatic®690 accessories is given in the WTW
catalog and on the Internet.
1 Pull the protective cap off the protective hood of the sensor.
2 Leave the sensor to lie in the air for at least 60 minutes while it
is switched on (polarization).
For the sensor to polarize, the following conditions must be
fulfilled:
The sensor is connected with the measuring transmitter.
The measuring transmitter is in operation
3 Calibrate the sensor (see operating manual of the measuring
transmitter).

TriOxmatic®690 Measuring / Operation
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4 Measuring / Operation
4.1 Measuring
WARNING
Contact with the sample can lead to danger to the user!
Depending on the type of sample, suitable protective measures
must be taken (protective clothing, protective goggles, etc.).
For measuring submerse the operable sensor in the test sample. The
measured value is available immediately on submersing.
Minimum approach flow The minimum required approach flow at the sensor must be present
during measurement (see chapter 7 TECHNICAL DATA). The minimum
approach flow can, e.g. be present due to:
natural movement of the water (flow rate, sea disturbance)
turbulences in the activated sludge basin.
4.2 Calibration
4.2.1 General information on calibration
Why calibrate? During the operation of a D.O. sensor, the slope of the D.O. sensor
changes with time. The calibration procedure determines the current
slope of the sensor.
When to calibrate? Calibrate before measuring and at regular intervals (depending on the
application).
Calibration procedure, Ideally, calibration takes place in water vapor-saturated air. To do so,
position the sensor approx. 2 cm above a water surface, for example in
a narrow bucket or similar container with water.
In the case of air temperatures under 5 °C we recommend to calibrate
not in air but in air-saturated water that has a higher temperature. You
obtain air-saturated water by pouring water several times in and out of
two vessels so that it sparkles.
Do not suspend the sensor on the sensor connection cable.
Use a sensor holder or armature. Information on this and
other TriOxmatic®690 accessories is given in the WTW
catalog and on the Internet.

Measuring / Operation TriOxmatic®690
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4.2.2 Calibration in water vapor-saturated air
Calibrating position
For calibration the membrane always has to be clean, for
calibration in air it has to be dry. Clean contaminated
sensors before calibration (see section 5.2 CLEANING THE
SENSOR SHAFT AND MEMBRANE).
1 If necessary, clean the sensor and membrane and dry the
membrane (see section 5.2 CLEANING THE SENSOR SHAFT AND
MEMBRANE).
2 Bring the sensor into the calibrating position.
To do so, position the sensor approx. 2 cm above a water
surface, best in a narrow bucket or similar container with water.
When doing so, no liquid should be brought on the membrane.
3 Start calibration as described in the operating manual of the
measuring transmitter.
In the case of air temperatures under 5 °C do not calibrate
the sensor in air but in air-saturated water that has a higher
temperature. You obtain air-saturated water by pouring
water several times in and out of two vessels so that it
sparkles.
Then immerse the sensor in a vessel with air-saturated
water (calibrating position) and calibrate as described
above.
2cm

TriOxmatic®690 Measuring / Operation
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4.3 Function check
The function check is the simplest way of letting you know whether the
sensor needs to be cleaned and calibrated.
Function check in water
vapor-saturated air
Proceed as follows:
Measured values within
the required precision
If the measured value lies within the range of precision required by the
user, no cleaning or recalibrating is necessary.
Example:
The function check can either be performed in water vapor-
saturated air or in air-saturated water.
In the case of air temperatures under 5 °C we recommend
to perform the function check not in air but in air-saturated
water that has a higher temperature.
The function check is carried out in the measuring mode, %
saturation.
1 Take the sensor out of the measuring solution and position it
approx. 2 cm above a water surface, best in a narrow bucket or
similar container with water. When doing so, no drops of liquid
should be on the membrane.
2cm
2 Wait at least 15 minutes for the temperature to adapt.
3 On the measuring transmitter, select Saturation (unit %) and
switch to the measured value display.
4 Read the measured value and determine whether it lies within
the range of precision required by the user.
If there are large temperature differences between the
sample and the air above the surface of the water, a
balancing period of more than 15 minutes may be required.

Measuring / Operation TriOxmatic®690
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Required precision 5 %
Measured value in air: 97 % saturation (nominal value: 100%)
No cleaning or recalibration is necessary as the measurement error
lies within the range of precision required by the user.
Measured values
outside the required
precision
If the measured value lies outside the range of precision required by the
user, clean the sensor shaft and membrane (see section 5.2) and
calibrate the sensor (see section 4.2).
In the case of air temperatures under 5 °C do not perform
the function check in air but in air-saturated water that has
a higher temperature. You obtain air-saturated water by
pouring water several times in and out of two vessels so
that it sparkles.
Then submerse the sensor in a vessel with air-saturated
water and perform the function check as described above.

TriOxmatic®690 Maintenance, cleaning, disposal, and replacement
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5 Maintenance, cleaning, disposal, and
replacement
5.1 General maintenance instructions
WARNING
Contact with the sample can lead to danger to the user!
Depending on the type of sample, suitable protective measures
must be taken (protective clothing, protective goggles, etc.).
5.2 Cleaning the sensor shaft and membrane
For normal operation (e.g. municipal wastewater), cleaning and
calibration are strongly recommended:
in the case of pollution (according to visual check)
in the case of suspected incorrect measured values (usually too low)
if the measured value lies outside the range of precision required by
the user during the function check.
Cleaning agents
Cleaning
Contamination Cleaning agents
Sludge and loosely adhering
dirt, biological deposits
Soft cloth or soft sponge, warm
tapwater with detergent
Salt and / or lime deposits Acetic acid (volume percentage =
20 %), soft cloth or soft sponge
1 Pull the sensor out of the sample.
2 Get rid of any coarse contamination on the sensor (e.g. brush
it off in a bucket of tapwater, wash it down with a hose or wash
it off with a cloth).
3 Unscrew the protective hood from the sensor.

Maintenance, cleaning, disposal, and replacement TriOxmatic®690
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CAUTION
Acetic acid irritates the eyes and the skin. When handling acetic
acid, always wear protective gloves and protective goggles.
NOTE
Clean the membrane very carefully!
Make sure the membrane is not damaged, e.g. by sharp-edged ob-
jects, by laying it on sharp stones, etc.
4Carefully clean the sensor shaft and membrane as specified
in the CLEANING AGENTS section.
5 Then, rinse it thoroughly with tap water.
6 Also clean and rinse the protective hood.

TriOxmatic®690 Maintenance, cleaning, disposal, and replacement
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7 Screw the protective hood back on again.
8 If necessary, carefully dry the membrane with a lint-free paper
towel.
9 Calibrate the sensor (see section 4.2 CALIBRATION).

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5.3 Changing the electrolyte and membrane cap
WTW delivers the sensor ready for operation. The electrolyte solution
and membrane cap must only be replaced if:
a calibration error occurs due to a highly contaminated
membrane
the membrane is damaged (SensLeck or SensReg message)
the electrolyte solution is depleted or the counter electrode is
poisoned (SensReg message)
after the gold working electrode and silver counter electrode have
been cleaned
NOTE
Before unscrewing the membrane cap, disconnect the sensor from the
instrument. Otherwise, undesirable electrochemical reactions can oc-
cur that may lead to the destruction of the sensor.
Changing the electrolyte
and membrane cap
CAUTION
Unscrew the membrane cap for maintenance purposes
only. After doing so, always use a new membrane cap!
1 Pull the sensor out of the sample.
2 Get rid of any coarse contamination on the sensor (e.g. brush
it off in a bucket of tap water, wash it down with a hose or wash
it off with a cloth).
3 Disconnect the sensor from the instrument.
4 Unscrew the protective hood from the sensor.

TriOxmatic®690 Maintenance, cleaning, disposal, and replacement
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The ELY/A electrolyte solution irritates eyes, skin and mucus
membranes. If it comes into contact with the eyes, rinse
thoroughly with water and consult a doctor! During working
activities, always wear suitable protective gloves and protective
goggles/face shield! Follow the safety datasheet.
5 Unscrew the membrane cap (for disposal of
membrane cap and electrolyte solution, see section 5.7).
6 Rinse the sensor head with tap water.
7 Carefully rub the silver counter electrode with a paper towel
and rinse it with deionized water.

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8 Thoroughly rinse the sensor head with electrolyte solution.
9 Fill a new WP 600 membrane cap with ELY/A electrolyte
solution (see section 5.8 MAINTENANCE EQUIPMENT AND
REPLACEMENT PARTS).
10 Throw away the first filling and fill the membrane cap with
electrolyte solution once more.

TriOxmatic®690 Maintenance, cleaning, disposal, and replacement
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CAUTION
The ELY/A electrolyte solution irritates eyes, skin and mucus
membranes. If it comes into contact with the eyes, rinse
thoroughly with water and consult a doctor! During working
activities, always wear suitable protective gloves and protective
goggles/face shield! Follow the safety datasheet.
11 Remove any air bubbles by carefully tapping the membrane
cap.
12 Screw the membrane cap onto the shaft while holding the
sensor at an angle. Excess electrolyte solution is forced out of
the ventilation area.
13 The filling should be free of air bubbles as far as possible.
However, small air bubbles do not cause any interference.
14 After approx. 60 minutes polarization time, the sensor is ready
for operation.
15 Recalibrate the sensor.
Ventilation area (hold upward)

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Precision
measurements
Recommendation: In order to carry out precision measurements, leave
the sensor to polarize for a longer period of time, e.g. overnight, and
recalibrate it the following day.
5.4 Cleaning the electrodes
The counter electrode and reference electrode always show a
coloration. This is necessary for the operation of the sensor.
This is not contamination. Cleaning is only required in cases of slopes
that are too small or too large (the sensor cannot then be calibrated)
that cannot be resolved by changing the membrane cap and electrolyte
solution.
NOTE
Before unscrewing the membrane cap, disconnect the sensor from the
instrument. Otherwise, undesirable electrochemical reactions can oc-
cur that may lead to the destruction of the sensor.
Preparatory activities
In the following cases, you must refill the sensor once
more:
If there are large air bubbles
If there are air bubbles on the gold working electrode
For measurements at high water pressure, even if small
air bubbles are present. Otherwise, the membrane and,
as a result, the measuring characteristics could change.
If the sensor cannot be calibrated.
1 Pull the sensor out of the sample.
2 Get rid of any coarse contamination on the sensor (e.g. brush
it off in a bucket of tap water, wash it down with a hose or wash
it off with a cloth).
3 Disconnect the sensor from the instrument.