wtw VARiON Plus 700 IQ User manual

VARiON®Plus 700 IQ
ba75580e03 04/2007
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
sensor. 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 2007, WTW GmbH
Reprinting - even as excerpts - is only allowed with the explicit written
authorization of WTW GmbH, Weilheim.
Printed in Germany.

VARiON®Plus 700 IQ Contents
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VARiON®Plus 700 IQ - Contents
1 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1
1.1 How to use this component operating manual . . . . . . . . 1-1
1.2 Structure of the combination sensor
VARiON®Plus 700 IQ . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2
1.3 Recommended fields of application . . . . . . . . . . . . . . . . 1-4
2 Safety instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1
2.1 Authorized use . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2
2.2 General safety instructions . . . . . . . . . . . . . . . . . . . . . . . 2-2
3 Commissioning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1
3.1 Scopes of delivery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1
3.2 IQ SENSOR NET system requirements . . . . . . . . . . . . . . 3-1
3.3 Notes on the handling of the electrodes . . . . . . . . . . . . . 3-2
3.3.1 Reference electrode . . . . . . . . . . . . . . . . . . . . . 3-2
3.3.2 Measurement electrodes and compensation
electrodes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-3
3.4 Preparing the sensor for measurement . . . . . . . . . . . . . 3-4
3.4.1 Equipping the sensor with electrodes . . . . . . . . 3-4
3.4.2 Mounting the protective hood . . . . . . . . . . . . . . 3-5
3.4.3 Connecting the sensor to the IQ SENSOR NET . 3-6
3.5 Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-8
3.5.1 General information . . . . . . . . . . . . . . . . . . . . . . 3-8
3.5.2 Setting table of the VARiON A
(ammonium sensor) . . . . . . . . . . . . . . . . . . . . . 3-9
3.5.3 Setting table of the VARiON N (nitrate sensor) 3-11
4 Matrix adjustment, check and calibration . . . . . . . . . 4-1
4.1 General information . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1
4.2 Matrix adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-3
4.2.1 General information on matrix adjustment . . . . 4-3
4.2.2 Carrying out the matrix adjustment . . . . . . . . . . 4-3
4.2.3 Result of the matrix adjustment . . . . . . . . . . . . . 4-4
4.3 Check and calibration in standard solutions . . . . . . . . . . 4-6
4.3.1 General information on checking and
calibrating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-6
4.3.2 Result of the check . . . . . . . . . . . . . . . . . . . . . . 4-8
4.3.3 Result of the calibration . . . . . . . . . . . . . . . . . . . 4-9

Contents VARiON®Plus 700 IQ
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5 Measuring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1
5.1 Measuring operation . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-1
5.2 Factors affecting the measured value . . . . . . . . . . . . . . .5-1
6 Maintenance and electrode exchange . . . . . . . . . . . . 6-1
6.1 General maintenance notes . . . . . . . . . . . . . . . . . . . . . .6-1
6.2 Exterior cleaning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6-3
6.3 Exchanging the electrodes . . . . . . . . . . . . . . . . . . . . . . .6-5
6.4 Polishing the chloride electrode . . . . . . . . . . . . . . . . . . .6-6
7 Replacement parts and accessories . . . . . . . . . . . . . 7-1
7.1 Electrodes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7-1
7.2 General accessories . . . . . . . . . . . . . . . . . . . . . . . . . . . .7-1
8 What to do if ... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-1
8.1 Interpretation of the drift voltage . . . . . . . . . . . . . . . . . . .8-1
8.2 Error causes and remedies . . . . . . . . . . . . . . . . . . . . . . .8-2
9 Technical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-1
9.1 Measuring characteristics . . . . . . . . . . . . . . . . . . . . . . . .9-1
9.2 Application conditions . . . . . . . . . . . . . . . . . . . . . . . . . . .9-2
9.3 General data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9-3
9.4 Electrical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9-4
9.5 Data of the VARiON®Plus electrodes . . . . . . . . . . . . . . .9-5
9.5.1 Response times . . . . . . . . . . . . . . . . . . . . . . . . .9-5
9.5.2 Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9-5
9.5.3 Weights . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9-5
10 Indexes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-1
10.1 Explanation of the messages . . . . . . . . . . . . . . . . . . . .10-1
10.1.1 Error messages . . . . . . . . . . . . . . . . . . . . . . . .10-1
10.1.2 Info messages . . . . . . . . . . . . . . . . . . . . . . . . .10-2
10.2 Status info . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10-4

VARiON®Plus 700 IQ Overview
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1 Overview
1.1 How to use this component operating manual
Structure of the
IQ SENSOR NET
operating manual
Fig. 1-1 Structure of the IQ SENSOR NET operating manual
The IQ SENSOR NET operating manual has a modular structure like the
IQ SENSOR NET itself. It consists of a system operating manual and the
operating manuals of all the components used.
Please file this component operating manual in the ring binder of the
system operating manual.
IQ Sensor Net Operating Manual
System
Operating
Manual
(Ring Binder)
IQ Sensor
Operating
Manual
MIQ Module
Operating
Manual
MIQ Terminal
Operating
Manual
Component Operating Manuals

Overview VARiON®Plus 700 IQ
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1.2 Structure of the combination sensor
VARiON®Plus 700 IQ
Fig. 1-2 Structure of the combination sensor VARiON®Plus 700 IQ
Electrodes For a VARiON®Plus 700 IQ combination sensor ready to measure, a
jointly used reference electrode and at least one ion sensitive electrode
for the main measured parameters (ammonium, nitrate) are required.
The electrodes are screwed into the electrode support. The electrode
support has four receptacles for this.
Automatic interfering
ions compensation
The VARiON®Plus 700 IQ enables the automatic interfering ions
compensation for one main measured parameter. Thus the influence of
certain interfering ions due to measuring technique can be
automatically compensated for.
Interfering ions in water / waste water applications are mostly chloride
for nitrate measurement and potassium for ammonium measurement.
To determine the interfering ions concentration, another electrode
(compensation electrode) is mounted into a free receptacle.
Note
Information on the fundamentals of measuring with ion sensitive
electrodes are given in the WTW primer, ION SELECTIVE MEASUREMENT
IN ONLINE ANALYSIS.
Operating modes and
electrode equipment
Due to its modular structure, the VARiON®Plus 700 IQ can be adapted
to various requirements (see table on the following page).
1Protective hood
2Temperature probe
3Electrode support with electrodes (sample equipment)
4Sensor shaft
5Plug head connector
1 2 3 4 5

VARiON®Plus 700 IQ Overview
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Notes:
The reference electrode has an extra receptacle marked by a recess.
The ion sensitive electrodes can be mounted in the remaining three
receptacles in any order. Empty receptacles have to be closed with the
VARiON®BP blind plug.
Operating mode Electrode equipment
Ammonium
measurement,
compensated
Nitrate measurement,
compensated,
Ammonium
measurement,
compensated,
plus nitrate
measurement
Nitrate measurement,
compensated,
plus ammonium
measurement
Ammonium
measurement
Nitrate measurement
Ammonium
measurement,
nitrate measurement
Ref
VARiON®Plus NH4
VARiON®Plus K
Blind plug
VARiON®Ref
(recess)
Ref
VARiON®Ref
VARiON®Plus NO3
VARiON®Plus Cl
Blind plug
Ref
VARiON®Ref
VARiON®Plus NH4
VARiON®Plus K
VARiON®Plus NO3
Ref
VARiON®Ref
VARiON®Plus NO3
VARiON®Plus Cl
VARiON®Plus NH4
Ref
VARiON®Plus NH4
Blind plug
Blind plug
VARiON®Ref
Ref
VARiON®Ref
VARiON®Plus NO3
Blind plug
Blind plug
Ref
VARiON®Ref
VARiON®Plus NH4
VARiON®Plus NO3
Blind plug

Overview VARiON®Plus 700 IQ
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Calibration free
operation
The VARiON®Plus 700 IQ combination sensor is immediately ready to
measure after being equipped with electrodes. For precise
measurements, it is only necessary to adjust the electrodes to the
sample matrix ("matrix adjustment"). In the recommended application
(see section 1.3 RECOMMENDED FIELDS OF APPLICATION), the measuring
characteristics of the electrodes remain stable for their entire service
life. Thus, calibration is no longer required.
Possible changes of the sample matrix can be determined by
occasional comparison measurements (e.g. photometer) and
compensated for by a new matrix adjustment. The sensor does not
have to be taken out of the sample for this.
Shielding of the
VARiON®Plus 700 IQ
The VARiON®Plus 700 IQ combination sensor and the corresponding
electrodes in conjunction with the IQ SENSOR NET system form a
measuring system that is protected to a high degree against low and
high frequency interference as well as against the indirect effects of
lightning strikes.
1.3 Recommended fields of application
The VARiON®Plus 700 IQ combination sensor is a sensor for the online
determination of ammonium ions and/or nitrate ions in water / waste
water applications. It supplements D. O. measurement in the aeration
tank of waste water treatment plants and enables an efficient process
control of nitrogen removal.
Note
More detailed information on measuring with ion sensitive electrodes is
given in the WTW primer, ION SELECTIVE MEASUREMENT IN ONLINE
ANALYSIS.

VARiON®Plus 700 IQ Safety instructions
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2 Safety instructions
This component operating manual contains special instructions that
must be followed in the operation of the VARiON®Plus 700 IQ
combination sensor. Thus, it is essential to read this component
operating manual before carrying out any work using this sensor. In
addition to this manual, the SAFETY chapter of the IQ SENSOR NET
system operating manual must be followed.
Always keep this component operating manual together with the
system operating manual and any other component operating manuals
in the vicinity of the IQ SENSOR NET system.
Special user
qualifications
The VARiON®Plus 700 IQ combination sensor was developed for
applications in online measurement - essentially in the field of
wastewater treatment. Thus, we assume that the operators are familiar
with the necessary precautions to take when dealing with chemicals as
a result of their professional training and experience.
General safety
instructions
Safety instructions in this operating manual are identified by the
warning symbol (triangle) in the left column. The signal word (e. g.
"Caution") indicates the level of danger:
Warning
indicates instructions that must be followed precisely in order to
prevent serious dangers to persons.
Caution
indicates instructions that must be followed precisely in order to
avoid slight injuries or damage to the instrument or the
environment.
Other labels
Note
indicates notes that draw your attention to special features.
Note
indicates cross-references to other documents, e.g. operating
manuals.

Safety instructions VARiON®Plus 700 IQ
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2.1 Authorized use
The authorized use of the VARiON®Plus 700 IQ with the electrodes built
in consists of its use as a sensor within the IQ SENSOR NET.
Please observe the technical specifications according to chapter 9
TECHNICAL DATA. Only operation according to the instructions given in
this operating manual is considered to be authorized.
Any other use is considered to be unauthorized. Unauthorized use
invalidates any claims with regard to the guarantee.
Caution
Only connect and operate the sensor together with IQ Sensor Net
accessories.
2.2 General safety instructions
The sensor left the factory in a safe and secure technical condition.
Function and
operational safety
The failure-free function and operational safety of the sensor is only
guaranteed if the generally applicable safety measures and the special
safety instructions in this operating manual are followed during its use.
The failure-free function and operational safety of the sensor is only
guaranteed under the environmental conditions that are specified in
chapter 9 TECHNICAL DATA.
The specified temperature (chapter 9 TECHNICAL DATA) must be
maintained during the operation and transport of the sensor. Protect
the sensor, particularly against frost or overheating.
Caution
The sensor may only be opened by specialists authorized by
WTW.

VARiON®Plus 700 IQ Safety instructions
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Safe operation If safe operation is no longer possible, the sensor must be taken out of
operation and secured against inadvertent operation.
Safe operation is no longer possible if the sensor:
has been damaged in transport
has been stored under adverse conditions for a lengthy period of
time
is visibly damaged
no longer operates as described in this manual.
If you are in any doubt, contact the supplier of your sensor.
Obligations of the
operator
The operator of the sensor must ensure that the following rules and
regulations are followed when dealing with hazardous substances:
EEC directives for protective labor legislation
National protective labor legislation
Safety regulations
Safety data sheets of the chemical manufacturer.

Safety instructions VARiON®Plus 700 IQ
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VARiON®Plus 700 IQ Commissioning
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3 Commissioning
3.1 Scopes of delivery
WTW supplies the VARiON®Plus 700 IQ in sets for different measuring
requirements. Each set contains the following components:
Unequipped sensor VARiON®Plus 700 IQ. The electrode
receptacles are closed with blind plugs
Reference electrode, VARiON®Ref
Depending on the set, the suitable selection from the following
measurement and compensation electrodes:
–VARiON®Plus NH4 (ammonium measuring electrode)
–VARiON®Plus K (potassium compensation electrode)
– VARiON®Plus NO3 (nitrate measuring electrode)
–VARiON®Plus Cl (Chloride compensation electrode)
Special socket wrench
Protective hood VARiON®700 IQ-SK
Potassium chloride solution for storing the reference electrode
Operating manual and WTW primer, ION SELECTIVE MEASUREMENT IN
ONLINE ANALYSIS.
Note
Information on the available sets is given in the WTW catalog and on
the Internet.
3.2 IQ SENSOR NET system requirements
Software statuses of the
controller and terminal
components
Operation of the VARiON®Plus 700 IQ requires the following software
statuses in the IQ SENSOR NET, depending on the system:
DIQ/S 182 Software: Version 3.21 or higher
MIQ/C184 (XT) Controller software: Version 2.83 or higher
Terminal software: Version 2.91 or higher
MIQ/MC Controller software: Version 2.83 or higher
MIQ/T 2020
(PLUS)
Terminal software: Version 2.91 or higher
IQ software pack Software version: 5.00 or higher

Commissioning VARiON®Plus 700 IQ
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3.3 Notes on the handling of the electrodes
The electrodes of the VARiON®Plus 700 IQ combination sensor were
developed for the rough use in waste water treatment plants. They are,
however, precision parts that can be damaged by inappropriate use.
Therefore, exactly follow the instructions in the two following chapters.
3.3.1 Reference electrode
Commissioning
Fig. 3-1 Reference electrode with storing aids
In the delivery condition, the electrode is equipped with a watering cap
and a nut that protects the screw-in thread. The watering cap contains
3 mol/l potassium chloride solution. Before mounting, unscrew the
watering cap. Then, using the special hexagon key, unscrew the
electrode from the nut. Keep both storing aids in case you want to store
the electrode.
Caution
The junction of the reference electrode must not
dry up (follow notes on storage)
be damaged
be brought into contact with grease.
Notes on storage If you will not use the electrode for a longer period of time, screw the
electrode into the nut as far as it will go. Fill the watering cap to the brim
with 3 mol/l potassium chloride solution and tightly screw the watering
cap on the electrode by hand.
Watering cap
Junction
Reference electrode
Nut
Sealing ring

VARiON®Plus 700 IQ Commissioning
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3.3.2 Measurement electrodes and compensation electrodes
Commissioning
Fig. 3-2 Measurement electrode or compensation electrode with storing aids
In the delivery condition, each electrode is equipped with a watering
cap and a nut that protects the screw-in thread. Prior to installation, first
remove the watering cap and, using the special hexagon key, unscrew
the electrode from the nut. Keep both storing aids in case you want to
store the electrode.
Caution
The membrane of the electrode must not
dry up (follow notes on storage)
be damaged
be brought into contact with grease.
Notes on storage If you will not use the electrode for a longer period of time, screw the
electrode into the nut as far as it will go. Soak the foam insert in the
watering cap with VARiON®/ES-1 standard solution (lower
concentration) and plug the electrode into the watering cap.
Caution
Make sure to use the correct solution for the watering cap
(VARiON®/ES -1 standard solution). If you use the watering
solution of the reference electrode instead the function of the
electrode can be seriously damaged.
Watering cap
Electrode
Nut
Sealing ring

Commissioning VARiON®Plus 700 IQ
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3.4 Preparing the sensor for measurement
3.4.1 Equipping the sensor with electrodes
Caution
The sensor can be damaged by dirt and moisture. Before
mounting the electrodes make sure the area behind the sealing
ring of the electrodes and the receptacle are dry and clean. The
VARiON®Plus 700 IQ may only be submersed when the electrodes
or original blind plugs are mounted.
Note
More detailed information on the electrode equipment for the various
operating modes is given in the table on page 1-3.
Fig. 3-3 Equipping the sensor with electrodes.
All receptacles are closed with blind plugs in the delivery condition.
Screw the electrodes into the receptacles instead of the blind plugs.
When doing so observe the following points:
The receptacle for the reference electrode is marked by a recess. It
extends into the inside of the sensor clearly deeper than the other
three receptacles (see Fig. 3-3).
Measurement and
compensation electrodes
Reference
electrode
Blind plug
Mark for
reference electrode
Special socket wrench

VARiON®Plus 700 IQ Commissioning
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The measurement and compensation electrodes can be mounted in
the remaining three receptacles in any order.
During installation make sure the area behind the sealing ring of the
electrode and the receptacle are absolutely dry and clean.
Plug the electrode on the special socket wrench provided and insert
the electrode with the special socket wrench.
Screw until the electrode seats without any gap on the electrode
support. Thus the tightness and electrical contacting are granted.
Note
When mounted, the electrodes can be recognized by the features
described in section 6.3.
3.4.2 Mounting the protective hood
CH cleaning head
(option)
For permanent operation, we recommend to use the CH cleaning head
for compressed air-driven cleaning. It is mounted instead of the
standard protective hood. The compressed air cleaning is started time-
controlled via the IQ SENSOR NET system. Information on the required
components is given in the WTW catalog and on the Internet.
If no CH cleaning head is used the standard protective hood should
always be mounted for measuring. It protects the electrodes from rough
mechanical impact.

Commissioning VARiON®Plus 700 IQ
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Mounting the standard
protective hood
Fig. 3-4 Mounting the standard protective hood.
Cleaning the protective
hood
The coupling ring of the protective hood can be taken apart for cleaning
purposes (see section 6.2 EXTERIOR CLEANING).
3.4.3 Connecting the sensor to the IQ SENSOR NET
Connection cable The SACIQ sensor connection cable is required to connect the sensor.
Information on this and other IQ SENSOR NET accessories is given in
the WTW catalog and on the Internet.
Note
Do not suspend the sensor on the sensor connection cable. Use an
armature or electrode holder. Information on this and other IQ SENSOR
NET accessories is given in the WTW catalog and on the Internet.
Note
How to connect the SACIQ sensor connection cable to the
IQ SENSOR NET is described in chapter 3 INSTALLATION of the
IQ SENSOR NET system operating manual.
1 Loosen the coupling ring (1) of the protective hood.
2 Push the protective hood on the sensor as far as it will go.
3 Tighten the coupling ring of the protective hood.
1

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Are the plug
connections dry?
Before connecting the sensor and sensor connection cable, make sure
that the plug connections are dry. If moisture gets into the plug
connections, first dry the plug connections (dab them dry or blow them
dry using compressed air).
Connecting the sensor
to the sensor
connection cable
Fig. 3-5 Connect the sensor
1 Take the protective caps off the plug connections of the sensor
and the SACIQ sensor connection cable, and keep them safe.
2 Plug the socket of the SACIQ sensor connection cable onto the
plug head connector of the sensor. At the same time, rotate the
socket so that the pin in the plug head connector (1) clicks into
one of the two holes in the socket.
3 Then screw the coupling ring (2) of the sensor connection
cable onto the sensor up to the stop.
SACIQ
1
2

Commissioning VARiON®Plus 700 IQ
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3.5 Settings
3.5.1 General information
Automatic electrode
recognition
The VARiON®Plus 700 IQ software automatically recognizes the built-
in electrodes and checks the equipment for validity. Depending on the
equipment, the following sensors are displayed in the list of sensors:
Carrying out settings Switch to the main settings menu from the measured value display with
s. Then navigate to the setting menu (setting table) of the sensor.
The exact procedure is described in the relevant IQ SENSOR NET
system operating manual.
The setting tables of both sensors are described in the following
chapters.
Sensor overlapping
settings
Certain settings are sensor overlapping and can be made in any one of
the two setting tables. The setting is used by both sensors.
The sensor overlapping settings are:
Temperature mode (°C/°F)
Temp. adjustment
Sensor Designation
VARiON®Plus 700 IQ Ammonium sensor VARiON A
VARiON®Plus 700 IQ Nitrate sensor VARiON N