Xylem YSI VARiON Plus 700 IQ H User manual

OPERATING MANUAL
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VARiON®Plus 700 IQ H
MODULAR SENSOR FOR AMMONIUM AND NITRATE
FOR CLASS I DIVISION 2 APPLICATIONS

VARiON®Plus 700 IQ H
2ba76207e02 12/2020
Contact YSI
1725 Brannum Lane
Yellow Springs, OH 45387 USA
Tel: [phone]
800-765-4974
Email: [email protected]
Internet: www.ysi.com
Copyright ©2020 Xylem Inc.
For the most recent version of the manual, please visit
www.ysi.com.

VARiON®Plus 700 IQ H Contents
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VARiON®Plus 700 IQ H - Contents
1 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
1.1 How to use this component operating manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
1.2 Structure of the sensor VARiON®Plus 700 IQ H . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
1.3 Recommended fields of application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
2 Safety . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
2.1 Safety information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
2.1.1 Hazard warnings in this operating manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
2.1.2 Safety information on the product . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
2.1.3 Further documents providing safety information . . . . . . . . . . . . . . . . . . . . . . . . . . 9
2.2 Safe operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
2.2.1 Authorized use . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
2.2.2 Requirements for safe operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
2.2.3 Unauthorized use . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
2.3 Hazardous location use . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
3 Commissioning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
3.1 Scopes of delivery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
3.2 Notes on the handling of the electrodes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
3.2.1 Effects to be generally avoided . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
3.2.2 Reference electrode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
3.2.3 Measurement electrodes and compensation electrodes 14
3.3 Getting the sensor ready for measuring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
3.3.1 Equipping the sensor with electrodes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
3.3.2 Mounting the protective hood . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
3.3.3 Connecting the sensor to the IQ SENSORNET . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
3.4 Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
3.4.1 General information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
3.4.2 Setting table VARiON A (ammonium sensor) 21
3.4.3 Setting table VARiON N (nitrate sensor). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
3.4.4 Setting table VARiON K (potassium sensor). . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
3.4.5 Setting table VARiON Cl (chloride sensor). . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
4 Matrix adjustment, check and calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
4.1 General information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
4.2 Matrix adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
4.2.1 General information on matrix adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
4.2.2 Carrying out the matrix adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
4.2.3 Result of the matrix adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
4.2.4 Special functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
4.3 Check and calibration in standard solutions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
4.3.1 General information on checking and calibrating . . . . . . . . . . . . . . . . . . . . . . . . . 32
4.3.2 Result of the check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

Contents VARiON®Plus 700 IQ H
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4.3.3 Result of the calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
4.4 Sensor history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
5 Measuring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .38
5.1 Measurement operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
5.2 Factors affecting the measured value . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
6 Maintenance and electrode exchange . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
6.1 General maintenance instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
6.2 Exterior cleaning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
6.3 Exchanging the electrodes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
6.4 Polishing the chloride electrode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
7 Replacement parts and accessories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
7.1 Electrodes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
7.2 General accessories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
8 What to do if ... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .46
8.1 Interpretation of the drift voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
8.2 Error causes and remedies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
9 Technical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
9.1 Measuring characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
9.2 Application conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
9.3 General data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
9.4 Instrument safety . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
9.4.1 General instrument safety . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
9.4.2 Hazardous location ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
9.5 Electrical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
9.6 Data of the VARiON®Plus electrodes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
9.6.1 Response times . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
9.6.2 Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
9.6.3 Weights . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
10 Indexes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
10.1 Explanation of the messages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
10.1.1 Error messages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
10.1.2 Informative messages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
10.2 Status info . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
11 Contact Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
11.1 Ordering & Technical Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
11.2 Service Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59

VARiON®Plus 700 IQ H Overview
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1Overview
1.1 How to use this component operating manual
Structure of the
IQ SENSORNET operating
manual
Fig. 1-1 Structure of the IQ SENSORNET operating manual
The IQ SENSORNET operating manual has a modular structure like the
IQ SENSORNET 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 H
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1.2 Structure of the sensor VARiON®Plus 700 IQ H
Fig. 1-2 Structure of the sensor VARiON®Plus 700 IQ H
Electrodes For a VARiON®Plus 700 IQ H 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 H enables the automatic interfering ions
compensation for one main measured parameter.Thus the influence of
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.
If interfering ions concentrations should be dynamically compensated
for both main parameters (ammonium, nitrate), the interfering ions
concentration measured by another sensor can be used with the Link
(sensor to sensor) function (see IQ SENSORNET system operating
manual).
1Protective hood
2Temperature sensor
3Electrode support with electrodes (sample equipment)
4Sensor shaft
5Plug head connector
123 4 5
Information on the fundamentals of measuring with ion
sensitive electrodes is given in the primer, ION SELECTIVE
MEASUREMENT IN ONLINE ANALYSIS.

VARiON®Plus 700 IQ H Overview
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Operating modes and
electrode equipment
Due to its modular structure, the VARiON®Plus 700 IQ H can be
adapted to various requirements (see table on the following page).
Notes on the table:
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
Ref
VARiON®Plus NH4
VARiON®Plus K
Blind plug
VARiON®Plus
Ref (recess)
Ref
VARiON®Plus
Ref
VARiON®Plus NO3
VARiON®Plus Cl
Blind plug
Ref
VARiON®Plus
Ref
VARiON®Plus NH4
VARiON®Plus K
VARiON®Plus NO3
Ref
VARiON®Plus
Ref
VARiON®Plus NO3
VARiON®Plus Cl
VARiON®Plus NH4
Ref
VARiON®Plus NH4
Blind plug
Blind plug
VARiON®Plus
Ref
Ref
VARiON®Plus
Ref
VARiON®Plus NO3
Blind plug
Blind plug

Overview VARiON®Plus 700 IQ H
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Calibration free
operation
The VARiON®Plus 700 IQ H 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 characteris-
tics of the electrodes remain stable for their entire service life. Thus,
calibration is not recommended.
Possible changes of the sample matrix can be determined by occa-
sional comparison measurements (e.g. photometer) and compensated
for by a new matrix adjustment as necessary. The sensor does not
have to be taken out of the sample for this.
Shielding of the
VARiON®Plus 700 IQ H
The VARiON®Plus 700 IQ H sensor and the corresponding electrodes
in conjunction with the IQ SENSORNET 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
Stationary measurements in water/wastewater applications in Class I
Division 2 hazardous locations.
The VARiON®Plus 700 IQ H sensor is a sensor for the online determi-
nation 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.
Ammonium mea-
surement,
nitrate measurement
Operating mode Electrode equipment
Ref
VARiON®Plus
Ref
VARiON®Plus NH4
VARiON®Plus NO3
Blind plug
More detailed information on measuring with ion sensitive
electrodes is given in the primer, ION SELECTIVE
MEASUREMENT IN ONLINE ANALYSIS.

VARiON®Plus 700 IQ H Safety
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2 Safety
2.1 Safety information
2.1.1 Hazard warnings in this 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.
The hazard warnings are defined for the following levels of danger:
2.1.2 Safety information on the product
Note all labels, information signs and safety symbols on the product.
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-
DANGER
DANGER indicates an imminently hazardous situation
which, if not avoided, will result in death or serious injury.
WARNING
WARNING indicates a potentially hazardous situation
which, if not avoided, could result in death or serious
injury.
CAUTION
CAUTION indicates a potentially hazardous situation
which, if not avoided, may result in minor or moderate
injury.
NOTICE
NOTICE is used to address practices not related to per-
sonal injury.

Safety VARiON®Plus 700 IQ H
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tem:
Operating manuals of other components of the measuring system
(power packs, controller, accessories)
Safety datasheets of calibration and maintenance equipment (e.g.
cleaning solutions).
2.2 Safe operation
2.2.1 Authorized use
The authorized use of the VARiON®Plus 700 IQ H consists of its use as
a sensor in the IQ SENSORNET. Only the operation and running of the
sensor according to the instructions and technical specifications given
in this operating manual is authorized (see chapter 9 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 9 TECHNICAL DATA).

VARiON®Plus 700 IQ H Safety
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2.3 Hazardous location use
Rated sensor models The following sensor models is rated for hazardous location use:
VARiON®Plus 700 IQ H (YSI-Order No. 207040Y)
Hazardous location rated sensors are identified by the name plate with
the rating details engraved on the sensor shaft:
Name plate of a Hazloc
sensor (example)
DANGER
Explosion hazard.
Only hazardous location rated sensor models
("Hazloc Sensor") must be used in hazardous
locations. Read the name plate on the sensor shaft
and verify that the sensor is rated for your specific
application.
DANGER
Explosion hazard.
The associated apparatus MIQ/BB1 (YSI part no.
207001Y) has to be used for connection. Refer to the
following documents for proper installation:
Control drawing, YSI document no. 28123
(see MIQ/BB1 operating manual)
MIQ/BB1 operating manual
All applicable electrical code regulations.
DANGER
Explosion hazard.
This product does not meet the requirements of the
directive 94/9/EC (ATEX).
VARiON® Plus 700 IQ H
Hazloc Sensor
Rated: Class I Division 2 Groups A, B, C, D, T6
Class I Zone 2 Group IIC T6
0°C ≤ Ta ≤ +40°C
14...24 V DC/ 0,2 W
Control Drawing NO 28123
CONFORMS TO
UL 61010-1
UL 121201
CERTIFIED TO
CAN/CSA C22.2 # 61010-1
CAN/CSA C22.2 # 213

Commissioning VARiON®Plus 700 IQ H
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3 Commissioning
3.1 Scopes of delivery
The VARiON®Plus 700 IQ H sensor is provided in sets for different
measurement requirements. Each set contains the following compo-
nents:
Unequipped sensor VARiON®Plus 700 IQ H. The electrode recepta-
cles are closed with blind plugs
Reference electrode VARiON®Plus Ref
Depending on the set, the suitable selection from the following mea-
surement and compensation electrodes:
–VARiON
®Plus NH4 (ammonium electrode)
–VARiON
®Plus K (potassium electrode for compensation)
–VARiON
®Plus NO3 (nitrate electrode)
–VARiON
®Plus Cl (chloride electrode for compensation)
Special socket wrench
VARiON®700 IQ-SK protective hood
Potassium chloride solution for storing the reference electrode
Operating manual
3.2 Notes on the handling of the electrodes
The electrodes of the VARiON®Plus 700 IQ H sensor were developed
for the rough use in waste water treatment plants. They are, however,
precision parts that can be damaged by inappropriate use.
3.2.1 Effects to be generally avoided
Avoid the following effects that can adversely affect the measurement
characteristics of the electrodes or reduce their lifetime:
Drying-up of the electrode membrane and junction
Scratching of the electrode membrane and junction
Contact with fat, oil, alcohol, acids, lyes, tensides and similar sub-
stances
Information on the available sets is given in the YSI catalog
and on the Internet.

VARiON®Plus 700 IQ H Commissioning
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Cleaning with washing-up liquid (tenside!)
Cleaning with or storing in deionized water
Storing in wrong storing solution
Therefore, exactly follow the instructions in the two following chapters.
3.2.2 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 elec-
trode from the nut. Keep both storing aids in case you want to store the
electrode.
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.
The junction of the reference electrode must not
dry up (follow notes on storage)
be damaged
be brought into contact with grease.
Watering cap
Junction
Reference electrode
Nut
Sealing ring

Commissioning VARiON®Plus 700 IQ H
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3.2.3 Measurement electrodes and compensation electrodes
Commissioning
Fig. 3-2 Measurement 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.
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 concentra-
tion) and plug the electrode into the watering cap.
The membrane of the electrode must not
dry up (follow notes on storage)
be damaged
be brought into contact with grease.
Watering cap
Electrode
Nut
Sealing ring
NOTICE
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.

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3.3 Getting the sensor ready for measuring
3.3.1 Equipping the sensor with electrodes
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.
NOTICE
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 H may only be sub-
mersed when the electrodes or original blind plugs are
mounted.
More detailed information on the electrode equipment for
the various operating modes is given in chapter 1.2.
Measurement and
compensation electrodes
Reference
electrode
Blind plug
Mark for
reference electrode
Special socket wrench

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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).
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 is seated on the electrode support without
any gap. Thus the tightness and electrical contacting are granted.
3.3.2 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 stan-
dard protective hood. The compressed air cleaning is started time-
controlled via the IQ SENSORNET system. Information on the required
components is given in the 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.
When mounted, the electrodes can be recognized by the
features described in section 6.3.

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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).
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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3.3.3 Connecting the sensor to the IQ SENSORNET
Safety guidelines for
installation in a
hazardous location
Connection cable A sensor connection cable of the SACIQ type is required to connect the
sensor. The cable is available in different lengths.
Are the plug
connections dry?
Before connecting the sensor and sensor connection cable, please
make sure 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).
DANGER
Explosion hazard.
Only hazardous location rated sensor models
("Hazloc Sensor") must be used in hazardous
locations. Verify the rating on the product name
plate on the sensor shaft.
The associated apparatus MIQ/BB1 (YSI part no.
207001Y) has to be used for connection. Refer to the
following documents for proper installation:
Control drawing, YSI document no. 28123
(see MIQ/BB1 operating manual)
MIQ/BB1 operating manual
All applicable electrical code regulations.
DANGER
Explosion hazard.
For hazardous location use only the cable types list-
ed in the control drawing must be used.
How to connect the SACIQ sensor connection cable to the
terminal strip of a MIQ module is described in chapter 3
INSTALLATION of the IQ SENSORNET system operating man-
ual.
Do not suspend the sensor on the sensor connection cable.
Use a sensor holder or armature. Information on this and
other IQ SENSORNET accessories is given in the YSI cata-
log and on the Internet.

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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

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3.4 Settings
3.4.1 General information
Automatic electrode
recognition
The VARiON®Plus 700 IQ H software automatically recognizes the
built-in electrodes and checks the equipment for validity. Depending on
the equipment, the following sensors can be displayed in the list of sen-
sors:
* see setting table of the sensor
Sensor overlapping
settings
Certain settings are sensor overlapping and can be made in any one of
the setting tables. The setting is used by all sensors.
The sensor overlapping settings are:
Temperature mode (°C/°F)
Temp. adjustment
Carrying out settings Using <S>, switch from the measured value display to the main menu
of the settings. Then navigate to the setting menu (setting table) of the
sensor. The exact procedure is given in the relevant IQ SENSORNET
system operating manual.
The setting tables of the sensors are described in the following chap-
ters.
sensor Designation
VARiON®Plus 700 IQ H Ammonium sensor VARiON A
VARiON®Plus 700 IQ H Nitrate sensor VARiON N
VARiON®Plus 700 IQ H potassium sensor * VARiON K
VARiON®Plus 700 IQ H chloride sensor *
VARiON Cl