wtw NitraLyt NOA User manual

ba75408e04 12/2005
NitraLyt®NOA
NitraLyt®NOA/AT
Operating Manual
NitraLyt®nitrate combination electrode
NitraLyt®NOA reference electrode
NitraLyt®NOA/AT exchange electrode
NitraLyt NOA/AT
®
NitraLyt NOA
®

NitraLyt®NOA; NitraLyt®NOA/AT
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Accuracy when going to
press
The use of advanced technology and the high quality standard of our
products are the result of continuous development. This may result in
differences between this operating manual and your electrode. Also,
we cannot guarantee that there are absolutely no errors in this manual.
Therefore, we are sure you will understand that we cannot accept any
legal claims resulting from the data, figures or descriptions.
Note
The latest version of the present operating manual can be found on the
Internet under www.WTW.com.
Copyright ©Weilheim 2005, WTW GmbH
Reprinting - even as excerpts - is only allowed with the explicit written
authorization of WTW GmbH, Weilheim.
Printed in Germany.

NitraLyt®NOA; NitraLyt®NOA/AT Contents
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Contents
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Response times . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Aging . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Factors affecting the measured values . . . . . . . . . . . . . . . 16
Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Cleaning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Storage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Accessories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Technical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

Overview NitraLyt®NOA; NitraLyt®NOA/AT
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Overview
The NitraLyt®combination electrode forms a measuring system for the
online determination of nitrate ions. It supplements the oxygen and
ammonium measurement in the aeration tank and enables an efficient
aeration control.
The NitraLyt®combination electrode is used in the NitraLyt®700 IQ
sensor.
Structure of the
NitraLyt®combination
electrode
Caution
The membrane and junction of the electrode must never
!dry up (observe notes on storage)
!be damaged
!be brought into contact with grease.
1Membrane
2Junction
3Sealing rings for installation in NitraLyt®700 IQ
4Plug head connector
NitraLyt NOA/AT (exchange electrode)
®
1
2
3
4
NitraLyt NOA (reference electrode)
®

NitraLyt®NOA; NitraLyt®NOA/AT Assembly
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Assembly
Installing the
NitraLyt®NOA/AT
in the NitraLyt®NOA
reference electrode
1Remove the wet cap (5) and blind plug (6) from the reference
electrode. Store both accessories. You need them if you want
to store the reference electrode.
2Remove the watering cap (7) and nut (8) from the exchange
electrode.
Store both accessories. You need them if you want to store the
reference electrode.
3 Screw the NitraLyt®NOA/AT exchange electrode into the
NitraLyt®NOA reference electrode without leaving any gap.
A flat wrench (wrench size 13 mm) or the protective hood of the
sensor is suitable as a wrench (see following figure).
6
5
7
8
Protection hood

Assembly NitraLyt®NOA; NitraLyt®NOA/AT
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Note
After installing the electrode tap your finger against the combination
electrode to remove any air bubbles from the back of the membrane.
When doing so hold the electrode in an upright position (membrane
downward).
Installing the
combination electrode
in the NitraLyt®700 IQ
sensor
Instructions on how to install the combination electrode in the sensor
are given in the operating manual of the sensor.
Response times
The response time depends on the concentration range. It is
!several seconds at high concentrations,
!several minutes near the detection limit.
Aging
Every electrode undergoes a natural aging process. The response time
increases and the slope decreases with the age of the electrode. The
following factors shorten the lifetime considerably:
!Incorrect storage
!Special measuring conditions (e.g. organic solutions, frequent
measurement with high concentrations of interfering ions)
!High temperatures and high temperature changes
Caution
Greases, oils, certain tensides and similar substances can
shorten the operational lifetime of the electrodes. Therefore, they
should not be present in the test sample.
The warranty does not cover damage caused by measuring conditions
and mechanical damage.
Factors affecting the measured values
Interferences !Chloride ions
Note
The effect of chloride ions on measurement and compensating actions
are described in detail in the WTW primer ION SELECTIVE MEASUREMENT
IN ONLINE ANALYSIS.

NitraLyt®NOA; NitraLyt®NOA/AT Maintenance
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Maintenance
In the case of increased response times or drifting measured values,
store the electrode in the standard solution ES/NO3_ISA-50 (ordering
information, see section ACCESSORIES) for several hours.
Subsequently, recalibrate.
Cleaning
Storage
1 to 2 days Attach the wet cap to the combined electrode with the exchange
electrode screwed in. Before doing so, wet the foam padding in the wet
cap with ES/NO3_ISA-50 standard solution (ordering information, see
section ACCESSORIES).
More than two days Uninstall the exchange electrode and store the components as follows.
Reference electrode:
Screw in the blind plug, wet the foam padding in the wet cap with
deionized water and plug on the wet cap.
Exchange electrode:
Screw the exchange electrode into the nut up to the stop. Before doing
so, wet the foam padding in the watering cap with ES/NO3_ISA-50
standard solution (ordering information, see section ACCESSORIES).
Subsequently, plug the exchange electrode into the wet watering cap.
Contamination Cleaning
Coarse contamination on the
junction of the NitraLyt®NOA
reference electrode
Carefully brush off contamination
under running water using a soft
toothbrush.
Contamination on the
membrane of the
NitraLyt®NOA/AT exchange
electrode
Splash the electrode with water.
Remove coarse contamination using
a soft toothbrush under running
water.

Accessories NitraLyt®NOA; NitraLyt®NOA/AT
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Accessories
Nitrate electrodes
Protective hood
Standard solutions for
nitrate calibration
Note
Further information can also be found in the operating manual of the
sensor NitraLyt®700 IQ.
Note
Information on other IQ SENSOR NET accessories is given in the WTW
catalog and on the Internet.
Note
Information on the fundamentals of measuring with ion sensitive
electrodes are given in the WTW primer, ION SELECTIVE MEASUREMENT
IN ONLINE ANALYSIS.
Designation Order no.
NitraLyt®NOA 107024
NitraLyt®NOA/AT 107026
Designation Order no.
NitraLyt®IQ-SK 107016
Designation Order no.
ES/NO3_ISA-5 5 mg/l NO3-N; 1000 ml 107030
ES/NO3_ISA-50 50 mg/l NO3-N; 1000 ml 107032
ES/NO3_ISA-500 500 mg/l NO3-N; 1000 ml 107034
SL NO3 19811 1000 mg/l NO3; 500 ml 250476
ES/NO3 10 g/L NO3; 1000 ml 120220

NitraLyt®NOA; NitraLyt®NOA/AT Technical data
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Technical data
Nitrate range mg/l NO3-N 0.1 ... 1000 mg/l
mg/l NO3-0.5 ... 4500 mg/l
Temperature range Operation 0°C ... 40 °C (32 ... 104 °F)
Storage/transport 0°C ... 40 °C (32 ... 104 °F)
Response time at 20 °C < 3 min
(when concentration changes from 5 mg/l to 50 mg/l NO3-N)
Type of protection IP 68; 0.2 bar
(complete combination electrode, mounted in the NitraLyt®700 IQ
sensor)
Connection technique Connection via S7 plug head connector
Material Enclosure:
NitraLyt®NOA
NitraLyt®NOA/AT
PVC
POM
Junction (NitraLyt®NOA) Polyethylene
Membrane (NitraLyt®NOA/AT) PVC, soft
Blind plug PVC
Wet cap PVC
Watering cap Silicone

Wissenschaftlich-Technische Werkstätten GmbH
Dr.-Karl-Slevogt-Straße 1
D-82362 Weilheim
Germany
Tel: [phone]
[phone]
Fax: [phone]
E-Mail: [e-mail]
Internet: http://www.WTW.com