Hamilton VisiWater DO, VisiWater DO Arc 120 FC10, VisiWater DO P Arc FC10 Operating Instructions Manual

VisiWater™ DO
Sensors

Operating Instructions

Applies to:
VisiWater DO Arc 120 FC10 (Stainless Steel)
VisiWater DO P Arc FC10 (Plastic)

Table of Contents

TABLE OF CONTENTSTABLE OF CONTENTS

1 General Information ..................................................4

1.1 Intended Use ................................................................. 4

1.2 About this Operating Instruction .................................... 4

2 Liability .......................................................................4

3 Safety Precautions and Hazards .............................5

3.1 General Precautions ...................................................... 5

3.2 Operation of VisiWater DO Sensor ................................5

3.3 Earthing .........................................................................7

3.4 Electrical Safety Precautions ......................................... 9

3.5 Chemical, Radioactive or Biological

Hazard Precautions ....................................................... 9

4 Product Description ..................................................9

4.1 General Description ....................................................... 9

4.2 Hardware Description .................................................. 10

4.3 Optical DO measurement ............................................ 11

4.4 VisiWater DO sensor with Micro-Transmitter inside ..... 11

5 Installation................................................................11

5.1 Unpacking ................................................................... 11

5.2 Configuring the VisiWater DO sensor with ArcAir ........ 12

5.2.1 Installing ArcAir Basic on the Computer ............ 12

5.2.2 Connecting an VisiWater DO Sensor

to ArcAir ............................................................12

5.2.3 Create User Accounts ....................................... 13

5.2.4 Configuring the VisiWater DO

Sensor Parameters ........................................... 13

5.2.5 Configuring the calibration settings ................... 14

5.2.6 Configuring the temperature settings ............... 15

5.2.7 Configuring the analog interface for

your process control system ............................. 15

5.2.8 Defining a measuring point name for

identification of the process .............................. 15

5.3 Install VisiWater DO sensor in your

Measuring Loop .......................................................... 16

5.3.1 Mechanical Process Connection ..................... 16

5.3.2 Cable Pin Designation ....................................... 16

5.3.3 Controlling 4–20 mA current interface

signals by pulse-width modulation .................... 16

5.3.4 Electrical Connection for Analog

4–20 mA Connection ........................................ 18

5.3.5 Electrical connection for the

digital RS485 interface ...................................... 18

6 Operation ................................................................ 20

7 Maintenance ............................................................21

7.1 Verify Sensor Status and ODO Cap Functionality ........ 21

7.2 Replacing the ODO Cap .............................................. 22

7.3 Calibration....................................................................22

7.3.1 Automatic Standard Calibration with ArcAir ..... 22

7.3.2 Calibration in Air (Calibration Point Air) .............. 23

7.3.3 Zero Point Calibration (Point Zero Oxygen) ....... 24

7.4 Product calibration ...................................................... 24

7.5 Cleaning ...................................................................... 25

8 Troubleshooting ...................................................... 26

8.1 Sensor Self-Diagnostic ................................................ 26

8.1.1 Wa r n i ng s ........................................................... 27

8.1. 2 Er ro r s ................................................................ 28

8.2 Getting Technical Support ........................................... 28

8.3 Returning VisiWater DO sensor for Repair ................... 28

9 Disposal .................................................................. 29

10 Ordering Information .............................................. 29

10.1 VisiWater DO Sensor ................................................. 29

10.2 Accessories ...............................................................30

10.3 Services .....................................................................30

Hamilton Warranty

Please refer to the General Terms of Sales (GTS).

Important note

Copyright © 2018 Hamilton Bonaduz AG, Bonaduz
Switzerland. All rights reserved. The reproduction of any
part of this document in any form is forbidden without the
express written agreement of Hamilton Bonaduz AG.

Contents of this document can be modified without
previous announcement. Technical modifications reserved.
Greatest possible care was used on the correctness of
the information in this manual. If errors should be
discovered nevertheless, Hamilton Bonaduz AG is
pleased to be informed about it. Regardless of this,
Hamilton Bonaduz AG cannot assume liability for any
errors in this manual or for their consequences.

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3Operating Instructions VisiWater

GENERAL INFORMATION • LIABILITY SAFETY PRECAUTIONS AND HAZARDS

1 General Information

1.1 Intended Use

The VisiWater DO sensors are intended for the measurement of
dissolved oxygen (DO) in water application.

Typical applications are water analytics in waste water industry,
lakes or rivers, fish farming. The statinless steel version has
a PG 13.5 to be used in armatures or pipes, while the plastic
version will be used in basin or ponds.

If the sensor is used in contact with gaseous or liquid organic
solvents, the resulting measurement accuracy in this application
must be separately checked and validated by the customer.

ATTENTION! VisiWater DO sensor is not intended

for hazardous atmospheres.

ATTENTION! The VisiWater DO sensor has a built-in
temperature sensor (NTC 22 kOhm). This temperature
sensor is to be used only for monitoring the sensor
conditions, not for controlling the process temperature.

1.2 About this Operating Instruction

These Operating Instructions are designed to support the inte­gration, operation and qualification of the VisiWater DO sensors.

To achieve this, it will describe the features of VisiWater DO sen­sor and its integration in Process Control Systems (PCS). Both
the hardware and the communication between the VisiWater DO
sensor and Process Control Systems are detailed in this manual.
After reading this manual the user should be capable of installing
and operating VisiWater DO sensors.

ATTENTION! Essential information for avoiding
personal injury or damage to equipment.

NOTE: Important instructions or interesting information.

in order to avoid consequential damages. The user is responsible
for taking suitable precautions in the event of a sensor failure.

NOTE: The VisiWater DO sensor is not intended and
specified as a safety device. A SIL (Safety Integrity Level)
certification is not available. It is in the sole responsibility
of the user to validate the VisiWater DO sensor according
the safety requirements of his application.

3 Safety Precautions and Hazards

ATTENTION! Read the following safety instruc­tions carefully before installing and operating the
VisiWater DO sensor.

3.1 General Precautions

For safe and correct use of VisiWater DO sensor, it is essential that
both operating and service personnel follow generally accepted
safety procedures as well as the safety instructions given in this
document, the VisiWater DO sensor operation instruction manual.

The specification given on the website www.hamiltoncompany.com
as regards temperature, pressure etc. may under no circumstanc­es be exceeded. Inappropriate use or misuse can be dangerous.

The lifetime of the VisiWater DO highly depends on the specific
conditions of the application. Temperature, pressure, chemicals
used may accelerate the ageing of both the sensor and its ODO
cap. See chapter 7 for replacement conditions.

Cleaning, assembly and maintenance should be performed by
personnel trained in such work. Before removing the sensor from
the measuring setup, always make sure that no process medium
can be accidently spilled. When removing and cleaning the sensor,
it is recommended to wear safety goggles and protective gloves.

The sensor can not be repaired by the operator and has to be
sent back to Hamilton for inspection.

Necessary precautions should be taken when transporting the
sensors. For repair or shipment the sensor should be sent back in
the original reusable packaging box. Every VisiWater DO sensor
sent back for repair must be decontaminated.

2 Liability

The liability of Hamilton Bonaduz AG is detailed in the document
«General Terms and Conditions of Sale and Delivery».

Hamilton is expressly not liable for direct or indirect losses arising
from use of the sensors. It must in particular be insured in this con­junction that malfunctions can occur on account of the inherently
limited useful life of sensors contingent upon their relevant applica­tions. The user is responsible for the calibration, maintenance and
regular replacement of the sensors. In the case of critical sensor ap­plications, Hamilton recommends using back-up measuring points

If the conditions described in these operating instructions manual
are not adhered to or if there is any inappropriate interference
with the equipment, all of our manufacturer’s warranties become
obsolete.

3.2 Operation of VisiWater DO Sensor

VisiWater DO sensors must be used for their intended applications,
and in optimum safety and operational conditions. The specifica­tions (such as temperature or pressure) defined in the section
entitled ‘Technical Specification’ must not be exceeded under any
circumstances (see www.hamiltoncompany.com).

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5Operating Instructions VisiWater

SAFETY PRECAUTIONS AND HAZARDS SAFETY PRECAUTIONS AND HAZARDS

Make sure that the PG13,5 (stainless steel version) thread and the
O-ring are not damaged when screwing the sensor into the pro­cess. O-rings are consumable parts which must be exchanged
regularly (at least once per year). Even when all required safety
measures have been complied with, potential risks still exist with
respect to leaks or mechanical damage to the armature. Wher­ever there are seals or screws, gases or liquids may leak out
undetected. Always make sure that no process medium can be
accidentally spilled before removing the sensor from its measure­ment setup. Make sure that no air or gas bubbles sticks to the
sensitive part of the sensor. As a consequence, the measurement
value could be unstable. Do not put stress on the system by
vibration, bending or torsion. Before use, verify that the sensor is
properly configured for your application.

Failure to observe and carry out the maintenance procedures
may impair the reliability and correct functioning of the measure­ment system.

ATTENTION! When unscrewing the PG13,5 (stain­less steel version) thread connection never turn the
sensor at the sensor head because you can loosen the
ODO Cap from the sensor shaft and fluid can reach
the interior of the sensor.

If the sensor is used in contact with gaseous or liquid organic
solvents, the resulting measurement accuracy and stability in
those applications must be separately checked and validated by
the customer.

3.3 Earthing

The sensor has to be mounted at the mounting location with an
electrostatically conductive of < 1MOhm. It is recommended to
assign the sensor shaft to earth (PE potential equalization) es­pecially in electromagnetically noisy environments. This signifi­cantly improves noise immunity and signal quality. The PG13,5
thread is connected to the metallic housing of the VisiWater DO
sensor. Two options for connecting the sensor to the process
environment are available.

Option 1: The Metal vessel is connected to earth via
stainless steel PG13,5 thread

The sensor shaft is connected to the metal tank over the PG13,5
thread

ATTENTION! To avoid humidity problems, make
sure that the ODO Cap is always attached firmly to the
sensor shaft, and that the O-ring between the shaft
and cap is undamaged.

ATTENTION! IP68 can be reached if the ODO Cap is
always attached firmly to the sensor shaft.

The integrated 4–20 mA analog output has been configured ac­cording to factory defaults. Before use, verify that the sensor is
properly configured for your application.

The ODO Caps are consumable parts of the VisiWater DO. The
operating lifetime of the ODO Caps depend strongly on the op­erating conditions of the process. Make sure that following cross
sensitivities and resistances of ODO Caps are respected.

Cross sensitivities and resistances of ODO Cap H0/H20

Measurement not influenced by Carbon Dioxide

Wetted parts resistant to Ethanol

Wetted parts not resistant to Chlorine, Ozone and Organic
Solvents such as Acetone,
Tetrahydrofuran (THF*)

Cross sensitivities and resistances of ODO Cap H2

Measurement not influenced by Carbon Dioxide, lipophilic
compounds

Wetted parts resistant to Organic Solvents such as
Ethanol*, Acetone*, (THF*),
Heptan*, Dimethylformamide*

Wetted parts not resistant to Chlorine and Ozone Gases

Green/Yellow Cable

Figure 1: Metal vessel with earth connection

NOTE: If the vessel is not connected to earth, Option 2

has to be applied.

Option 2: Glass or plastic vessel with plastic sensor
shaft (sensor not connected to earth via tank)

The glass or plastic tank has no connection to earth and
therefore it is necessary to connect the sensor shaft via a
screw clamp or sensor cable to earth.

*Tested for 30 min at 25°C

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7Operating Instructions VisiWater

SAFETY PRECAUTIONS AND HAZARDS PRODUCT DESCRIPTION

3.4 Electrical Safety Precautions

Green/Yellow Cable

Plastic
version
only!

SST Version

Figure 2: Glass or plastic vessel without ear th connection

Below several examples how to connect the shaft of the sensor
directly to earth as required in Figure 2 are shown.

Do not connect the sensor to a power source of any voltage
beyond the range stated in the power rating Technical Specifi­cations (see www.hamiltoncompany.com).

Make sure the cable is intact and properly plugged to avoid any
short circuit.

Keep VisiWater DO sensor away from other equipment which
emits electromagnetic radio frequency fields, and minimize static
electricity in the immediate environment of the optical measuring
parts. Carefully follow all the instructions in chapter 5.3 to avoid
electrical damage to the sensor. The contacts must be clean
and dry before sensor is connected to the cable.

ATTENTION! Switch off the power supply and
unplug the connector before dismounting the
VisiWater DO sensor.

ATTENTION! If the power supply (230VAC/24VDC)
is switched off or disconnected the reading on the
PCS is wrong.

External earth cable

3.5 Chemical, Radioactive or Biological Hazard Precautions

Selection of the appropriate safety level and implementation
of the required safety measures for working with VisiWater DO
sensor is the sole responsibility of the user.

If working with hazardous liquids, observe and carry out the
maintenance procedures, paying particular attention to cleaning
and decontamination. If VisiWater DO sensor becomes con­taminated with biohazardous, radioactive or chemical material,
it should be cleaned. Failure to observe and carry out the
maintenance procedures may impair the reliability and correct
functioning of the measuring module.

4 Product Description

4.1 General Description

Hamilton’s optical sensor has been the first optical dissolved
oxygen (DO) sensor for process measurement. With their micro
transmitter, VisiWater DO sensors enable direct communication
to the process control system via 4–20 mA standard signal or
digital Modbus.

Figure 3: Example clamps for conne cting the earth
to armature and metallic housing of the tank.

VisiWater DO sensor optical technology improves the measuring
performance and simplifies maintenance. Improvements com­pared to conventional electrochemical (amperometric) sensors
include flow independence, rapid start-up with no polarization
time, and simplified maintenance.

With the transmitter integrated, VisiWater DO sensors provide
more reliable measurements directly to your process control

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9Operating Instructions VisiWater

PRODUCT DESCRIPTION INSTALLATION

system. The µ-transmitter located in the sensor head stores all
relevant sensor data, including calibration and diagnostic informa­tion, simplifying calibration and maintenance.

Key benefits include:

• Optical measurement

• No separate transmitter needed

• Simple maintenance with robust industrial design

• Easy to install

• Direct analog or digital Modbus communication to the
process control system via 4–20 mA standard signal.

4.2 Hardware Description

The VisiWater DO sensor consists of a sensor head with inte­grated electronic and a sensor shaft in contact with the measured
medium. The sensor shaft is terminated by the optical dissolved
oxygen (ODO) cap, carrying the oxygen sensitive luminophore.
During development, special attention was paid to an optimum
sanitary design.

Fix cable

Fix cable

4.3 Optical DO measurement

The optical measurement principle is based on the so-called
luminescence quenching. The luminescence of certain organic
pigments (luminophore) is quenched in the presence of oxygen.
The luminophore absorbs the excitation light and release a part of
the absorbed energy by emission of fluorescence. In the pres­ence of oxygen, energy transfer takes place from the excited
luminophore to oxygen. The luminophore does not emit fluore­cence and the measurable fluorescence signal decreases.

1

Fluorescence process (without oxygen)

Light (excitation)

Luminophore

Light Absorption Excited State

2

Quenching in the presence of oxygen

Fluorescence

(emission)

Sensor Head with
micro transmitter

Process connection
PG13,5 stainless
steel

O-ring

Sensor shaft with
stainless steel

ODO Cap with oxyge n-sensitive
luminophore (sensory element)

Figure 4: VisiWater DO sensor hardware description.

Sensor Head
with micro
transmitter

Sensor shaft
with PVC
material

ODO Cap with oxyge n
sensitve luminophore
(sensory element)

Energy transfer

O

2

No fluorescence

Light Absorption Excited State

Figure 5: Fluorescence quenching by oxyge n

O

2

4.4 VisiWater DO sensor with Micro-Transmitter inside

With the micro-transmitter integrated, VisiWater DO sensors offer
fully compensated signal directly to the process control system.
Communication protocols include standard analog 4–20 mA. The
micro transmitter located in the sensor head stores all relevant
sensor data, including calibration and diagnostic information,
simplifying calibration and maintenance.

5 Installation

5.1 Unpacking

1) Unpack carefully the VisiWater DO sensor. Enclosed you will
find the VisiWater DO sensor, the Declaration of Quality, the
VisiWater DO sensor Instruction Manual, and the Stainless
Steel material Certificate.

2) Inspect the sensor for shipping damages or missing parts.

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11Operating Instructions VisiWater

INSTALLATIONINSTALLATION

5.2 Configuring the VisiWater DO sensor
with ArcAir

VisiWater DO sensors require application specific configuration.
Following parts are required to configure and calibrate Arc
sensors:

• ArcAir computer Software Solution

• External Power supply

USB RS485 Modbus Converter VisiWater DO

ArcAir

Figure 6: VisiWater DO sensor configuration with ArcAir.

Power Supply

5.2.1 Installing ArcAir Basic on the Computer

1) Download the Zip file «ArcAir» from the Hamilton webpage
www.hamiltoncompany.com (search for ArcAir).

2) Unpack the ZIP-File.

3) Do not plug in the Wireless Converter before the installation of
ArcAir is completed.

4) Install «ArcAir» by double clicking «ArcAir.exe» and follow the
instructions on the screen.

5.2.3 Create User Accounts

1) Start ArcAir application on computer

2) Click on «Backstage» left upper corner

3) Select «User Management»

4) Click the «Add» Button for opening the user editor

5) Type in the user details and password

6) Select the specific rights for the user

ATTENTION! First user is the administrator and all
user rights are assigned as default.

NOTE: Initial operation of ArcAir is in the laboratory
mode as long as no user account is created. Laboratory
mode does not require a login password and enable all
features in the installed license version.

5.2.4 Configuring the VisiWater DO
Sensor Parameters

1) Start the ArcAir application

2) Select the desired sensor

3) Open the drawer «Settings» (make sure you have the
«Sensor Settings» user right)

4) Configure the sensor

A description of the available settings is given below:

5.2.2 Connecting an VisiWater DO Sensor to ArcAir

1) Connect a sensors with the power supply 24VDC and wired
to RS485 USB Modbus Converter (242411).

2) Connect the USB-RS485 Modbus Converter to ArcAir.

3) Start ArcAir on the Computer

4) The ArcAir application recognizes and displays the connected
sensors automatically

ATTENTION! For automatic sensor login a unique
and global Operator Level S password for all intelli­gent sensors is required. Please make sure you have
added the same Operator Level S Password for all
Arc sensors in the ArcAir application under Back­stage/Settings/Operator Level S Password.

Parameter Default
Name Description Value Configuration Location

DO Unit These are the %vol. Required
measurement Values
physical units
%vol ., %s at.,
ug/l ppb,
mg/l ppm, mbar

T unit These are the °C Required Measurement/
temperature Values
physical units
K, °F, °C

Salinity The concentra- 0 mS/cm Default Measurement/
tion of dissolve parameter Parameter
oxygen in recommended
saturated water
is dependent
on the salinity

Air The par tial 1013 mbar Required, Measurement/
pressure pressure of application Parameter
oxygen is dependent
proportional to
the atmospheric
pressure or the
pressure of the
air supply to
the process

Measurement

/

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13Operating Instructions VisiWater

INSTALLATION INSTALLATION

5.2.6 Configuring the temperature settings

Parameter Default
Name Description Value Configuration Location

Measuring The measuring 3 sec.
Interval* interval can be default Parameter
set between parameter
1 sec. and
300 sec. The
LED flashes
once in the set
measure interval

Moving The sensor 0 (auto)
average uses a moving default Parameter
average over parameter
the measuring
points

Sensing Sensing 243515 Must Measurement/
Material Material are applic ation Parameter
different types dependent
of ODO Cap
which can be set
by entering the
Ref number of
the ODO Caps

Resolution The resolution 8 Recommended Measurement/
interval can be default Parameter
set between parameter
8-16. The mea­ suring interval
is on itself an
average over
8-16 individual
sub-measure­ ments.

* In calibration mode the sensor will automatically switch
to 3 sec sampling rate after the first calibration.

Recommended

Recommended

Measurement/

Measurement/

5.2.5 Configuring the calibration settings

Parameter Default
Name Description Value Configuration Location

Drift DO Higher drift 0.05%/min Recommend Calibration/
will interrupt default Calibration
the calibration parameter Set tings
process.
Warning
comes up
«drif t oxyge n»

Drift T Higher drift 0.5 K/min Recommend Calibration/
will interrupt default Calibration
the calibration parameter Settings
process. War­ ning comes
up «drift
temperature»

Parameter Default
Name Description Value Configuration Location

Customer User defines -5°C to 50°C Recommend Status/
temperature temperature default Quality,
range range for DO parameter Counters
reading. No and
DO reading Tempe-
above 50°C ratures
possible

5.2.7 Configuring the analog interface for
your process control system

Parameter Default
Name Description Value Configuration Location

Interface The output of 4 –20 mA Recommended Interface/
Mode the 4-20 mA default A nalog
can be
configure linear,
bilinear or with
a fix value

Value at Defined 0%-vol Must Interface/
4 mA measurement application Analog
value for 4 mA dependent Output
output

Value at Defined 62.85-%vol Must Interface/
20 mA measurement application Analog
value for dependent Output
20 mA output

Mode in Current output No output Recommended Interface/
event of mode in case default Analog
warning of warnings parameter Output

Mode in Current output Continuous Recommended Interface/
event of mode in case output default Analog
errors of errors parameter Output

Output in Current output 3.5 mA Recommended Interface/
event of in case of default Analog
warning warnings parameter Output

Output in Current output 3.5 mA Recommended Interface/
event of in case of default Analog
error error parameter Output

Output for T Current output 3.5 mA Recommended Interface/
out of limit in case of default Analog
temperature parameter Output
out of limit

5.2.8 Defining a measuring point name for
identification of the process

Parameter Default
Name Value Settings Location Descriptions

Measuring User can 243650 – 1234 Optional Information /
point define a Info
sensor name Userspace
for better
identification
of the mea­ suring point

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15Operating Instructions VisiWater

INSTALLATION INSTALLATION

5.3 Install VisiWater DO sensor in your Measuring Loop

5.3.1 Mechanical Process Connection

The VisiWater DO PG13,5 Stainless Steel version is compatible
with all Hamilton process housings, including FlexiFit, Retractex,
RetractoFit and Hygienic Sockets.

Before installing the armatures, you should test that the seal is
tight and the parts are all in working order. Ensure that there is no
damage to the sensor or the armature. Check whether all O-rings
are in place in the appropriate grooves and are free of damage.
To avoid any mechanical damage to O-rings on assembly, they
should be slightly greased.

5.3.2 Cable Pin Designation

pulse width (ti) of a rectangular signal with a constant frequency,
the pulse duty factor (ti/T), is modulated and afterwards de­modulated by a low-pass filter to generate continuous analog
DC signals. The resulting value yi corresponds to the average
of the PWM signal (see Figures 8 and 9). The PWM-loads of the
Sensors have low-pass filters which are not able to eliminate all
AC fractions of the used PWM frequency of 5 kHz due to techni­cal impossibilities. Therefore, the current signals of the 4–20 mA
interfaces are still overlaid by a certain AC which should be
masked by lag smearing or input filters of the current input card of
the process control system (PCS). Recommended PCS settings
are a sampling rate below 3.5 kHz, an averaging over more than
1 s, and the use of galvanically separated inputs to avoid oscilla­tions. It is also possible to use mathematical functions or isolating
amplifiers for signal processing filtering if necessary. For detailed
technical advice about suitable isolating amplifiers, please contact
Hamilton technical support.

1

2

3

4

Shield

5

Figure 7: Requireme nts for electrical connection of VisiWater DO sensors

Pin Color Function

1 White - 4-20 mA Interface # 1

2 Brown Power Supply: + 24 VDC (7 to 30 V)
Start-up power: 1 W Continuous power
consumption: 600 mW

3 Green GND

4 Yellow RS485 (A)

5 Gray RS485 (B)

Shield Green-Yellow connected

5.3.3 Controlling 4–20 mA current interface signals by pulse-width modulation

Hamilton VisiWater DO sensors use the method of pulse-width
modulation (PWM) to adjust the DC currents of the 4–20 mA
interfaces corresponding to the measured values. In principle, the

Figure 8: Progress of a rectangular signal with a period T and a pulse
duration t

for the generation of an analog signal with the value y1.

1

Figure 9: Progress of a rectangular signal with a period T and a pulse duration t2
for the generation of an analog signal with the value y

.

2

ATTENTION! The VisiWater DO sensor generates
the 4-20 mA signals by pulse width modulation
(PWM) which is not compatible to all PCS systems.
Also a galvanic separation between the power supply
and the PCS is necessary for correct sensor func­tionality when used in 4-20 mA setups. Figure 12
illustrates a solution for the problem.

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17Operating Instructions VisiWater

INSTALLATION INSTALLATION

Analog interface 1 and 2

Galvanically not isolated, pulse width modulation with 5 kHz,
recommended PCS settings:

• Use galvanically separated inputs

• Sampling rate < 3 kHz and ≠ n * 5 kHz

• Average over > 1 s

5.3.4 Electrical Connection for Analog 4–20 mA Connection

The 4–20 mA interface enables direct connection of the VisiWa­ter DO sensor to a data recorder, indicator, control unit or PCS
with analog I/O. The VisiWater DO sensor works as a current
sink sensor and is passive. Connect the sensor according to the
pin designations (Chapter 5.3.2). The 4–20 mA interface of the
VisiWater DO sensors is pre-configured with default values for the
4–20 mA range, and measurement unit. Configure the 4–20 mA
interface according to your requirements for proper measurement
(Chapter 5.2.7).

Examples of circuit arrangement

Sensor

Pin 1

4–20 mA
regulation

Sensor power

Pin 2

U (7–30 VDC) Po wer Supp ly Sens or

Pin 3

Figure 10: Thre e-wire loop wiring diagram for the 4–20 mA interface.

White

4–20 mA c urrent

Brown

Green

Sensor

4–20 mA
regulation

Pin 1

White

4–20 mA c urrent

-

input

+

+

-

output

PCS

0 VDC; GND 1

–

+

galvanically

isolated

+ 24 VDC

0 VDC; GND 2

PCS

+

-

0 VDC; GND

Analog Input

Analog Input

parameters. VisiWater DO sensor are always connected to digital
controlling devices as a Modbus slave. To function, they require
a power supply (Pin 2 and 3, see below). The section entitled
«Configuring the VisiWater DO sensor parameters» describes
operation in digital mode.

Additional information:

The Modbus RTU communication protocol corresponds to
the Modbus-IDA standard (see www.modbus.org). VisiWater DO
sensor uses an open register set developed by Hamilton.
Additional information about the register content and structure
can be found in the VisiFerm DO programmers manual under
www.hamiltoncompany.com

The Modbus physical layer is described in detail with require­ments on cabling and line termination in the «Modbus Serial

>

line Protocol and Implementation Guide» www.modbus.org
Technical Resources / Modbus Specifications / Modbus Serial
line Protocol and Implementation Guide.

ATTENTION! Because all sensors are delivered
with factor y-default settings, each sensor must be
configured for its specific application before first use
(see the section entitled «Configuring VisiWater DO
sensor»).

The pins for digital the RS485 interface have the following
designation with respect to cable conductor colors:

Sensor fix cable Color

Power supply: +24 VDC Brown
(7 to 30 VDC), max. power
consumption 1 W.

Power supply: Ground Green

RS485 (A) Yellow

RS485 (B) Gray

Cable shield green-yellow

Example of circuit arrangement

Sensor power

Pin 2

U (7–30 VDC) Po wer Supp ly Sens or

Pin 3

Figure 11: The safest form of wiring, using an external isolation amplifier.
The figure represents 4–20 mA interface. (For detailed technic al advice, please
contact the technical support at Hamilton.)

Brown

Green

+ 24 VDC

0 VDC; GND

5.3.5 Electrical connection for the digital RS485 interface

The digital RS485 interface enables communication with
VisiWater DO sensor for performing measurements, for cali­brating the sensor and for changing the sensor’s configuration

Sensor

Pin 2

Pin 3

Pin 4

Pin 5

Figure 12: Wiring diagram for the RS485 inter face.

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DO Sens ors

Power supply

+24 VDC

+

-

0 VDC; G roun d

PCS

A

RS 485

B

Ground

19Operating Instructions VisiWater

OPERATION MAINTENANCE

Master device Distributors

120 Ohm

line termination

SDA(-)

SDB(+)

RDA(-)

RDB(+)

+ 24 VDC

Common

Figure 13: Multi-drop bus wiring for the Modbus two-wire mode.
Each sensor functions as a Modbus slave.

(option)

#1

A/A'

B/B'

+ 24 VDC

Common

#2

A/A'

B/B'

+ 24 VDC

Common

#3

A/A'

B/B'

+ 24 VDC

Common

#n

n≤31

A/A'

B/B'

+ 24 VDC

Common

120 Ohm

line termination

The serial Modbus connection between the RS485 port of the
master and the corresponding interfaces of the sensors has to
be ensured according to the EIA/TIA RS485 standard. Only one
sensor can communicate with the master at any time.

NOTE: In order to avoid signal reflection on the lines the
use of line termination resistors (120 Ohm each) is recom­mended. The effect of signal reflections becomes more
relevant with long cable length and/or high baud rates.

(option)

7) Verify the measurement in air on your control system

8) Mount the sensor to the armature or process connection
(Chapter 5.3)

NOTE: No oxygen measurement is performed at a
temperature higher than 50°C to protect the optoelec­tronics and enhanced the sensor lifetime.

NOTE: To ensure a correct measurement by changing
a ODO Cap type e.g. ODO Cap H0/H20

>

ODO Cap H2
the reference number of the ODO Cap should be config­ured in the Sensing Material register (See chapter
«Configuring the VisiWater DO Sensor Parameters».
Firmware version ODOUM042.hex ore higher is required.

7 Maintenance

Periodic maintenance routines need to be run in order to
ensure safe and reliable operation and measurement of sensor
and the accessories.

ATTENTION! Avoid any contact of the equipment

with corrosive media.

NOTE: In the connection scheme shown above, each
sensor must have the unique Modbus device address for
proper communication.

6 Operation

ATTENTION! Only use the sensor within the speci­fications (see www.hamiltoncompany.com). Failure to
do so may lead to damages or measurement failure.

1) Remove the protective caps from the VisiWater DO sensor shaft

2) Check the O-ring on the sensor shaft and verify if the ODO
Cap is screwed firmly to the sensor shaft (Chapter 7.2)

3) Verify if the sensing material is correct for the ODO Cap type
which can be set by entering the Ref number of the ODO Caps

4) Verify the functionality of the sensor including the ODO
cap (Chapter 7.1)

7.1 Verify Sensor Status and ODO Cap Functionality

1) Power the sensor and connect the sensor to ArcAir.

2) Control the traffic lights (Figure 14).

3) Please refer to the troubleshooting (Chapter 8) for the
next steps if the traffic light is not green.

4) Control the quality of the ODO cap in Sensor Status /
Quality Counter and Temperature / Quality Indicator and
change the ODO cap if required (Chapter 7.2).

The sensor is performing correctly.

No errors or warnings have been registered.

At least an error or a warning has been registered.

Verify the sensor errors and warnings in Sensor Status.

No communication between the sensor and ArcAir.

This may be due to a hardware failure.

Figure 14: Description of the traffic lights on ArcAir

5) Calibrate the sensor (Chapter 7.3)

6) Connect the sensor to the process control system (Chapter 5.3)

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21Operating Instructions VisiWater

MAINTENANCE MAINTENANCE

7.2 Replacing the ODO Cap

The exchange of ODO Cap can be performed very easily:

1) Unscrew the ODO cap from the shaft (Figure 15).

2) Exchange the O-ring.

3) Screw firmly the new ODO Cap onto the sensor shaft again.

4) Perform sensor calibration (Chapter 7.3).

NOTE: If the ODO Cap is mounted very firmly on the
shaft, and if you cannot obtain a good grip on the
stainless steel with your fingers, a silicone tube between
your fingers and metal may supply a better grip.

O-ring

unscrew

7.3.2 Calibration in Air (Calibration Point Air)

1) Install the sensor into the calibration setup with satured
medium (Figure 17).

2) Power the VisiWater DO and connect to ArcAir via RS485
Converter

3) Select the sensor in the sensor list.

4) Open the Calibration tab.

5) Select Calibration Point Air

6) Click Start to start the calibration wizard.

7) Follow the instructions on the screen.

Figure 15: Replacing the ODO Cap (symbolic picture)

7.3 Calibration

The VisiWater DO sensors provide two kinds of sensor calibra­tion: automatic standard calibration, and product calibration.
The automatic standard calibration and the product calibration
may be performed using ArcAir (see chapter 5.2).

7.3.1 Automatic Standard Calibration with ArcAir

VisiWater DO sensors are calibrated at two points: in air and
in an oxygen-free environment. During calibration, the sensor
controls automatically the stability of the oxygen and tempera­ture signals.

NOTE: For greater measurement accuracy ensure that
temperature difference between calibration medium and
process medium is minimal.

O

2

H2O

Magnetic stirrer

Figure 17: Calibration setup in saturated medium

NOTE: Calibration with air-saturated water is less

accurate due to the slow saturation process of air in water.

NOTE: Let the sensor to acclimatize to the environment
temperature before calibrating. It may takes up to 6
minutes. VisiWater DO Plastic version only.

NOTE: The value of the saturated oxygen concentration
at different temperatures, different pressures and air
humidity play an important role for the calibration of
dissolved oxygen. VisiWater DO sensor refers to a
concentration in water saturated air and from the factory
settings of atmospheric pressure of 1013 mbar at 25°C.

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23Operating Instructions VisiWater

MAINTENANCE MAINTENANCE

N

2

7.3.3 Zero Point Calibration (Point Zero Oxygen)

1) Install the sensor into calibration tube and connected
the Nitrogen calibration gas (Figure 16).

2) Power the VisiWater DO and connect to ArcAir via RS485
Converter

3) Select the sensor in the sensor list.

4) Open the Calibration tab.

5) Select Zero Point calibration.

6) Immerse the sensor into an oxygen-free environment
(Figure 16) for e.g. nitrogen. Verify that the flow rate does
not exceed 0.5 L/min and avoid overpressure.

7) Click Start to start the calibration wizard.

8 Follow the instructions on the screen.

If product calibration is activated, the VisiWater DO sensor
calibration curve is calculated from the data of last calibration at
zero point 1 and from the data of the product calibration (Figure

18). In order to restore the original standard calibration curve,
the product calibration can be at any time by selecting on the
Product calibration command «cancel». A new standard calibra­tion cancels a product calibration as well.

Figure 18: Effe ct of a product calibration (CP6) on an existing standard calibration
function based on the Zero Point Calibration (CP 1) and the Air Calibration (CIP 2).

Sensor for calibration
in zero oxygen

Tube: on the top open
(no overpressure)

Valve for setting the
flow of 0.5 L/min

Nitrogen with
purity of 5.0

Figure 16: Zero point calibration setup

7.4 Product calibration

The product calibration is an in-process calibration procedure in
order to adjust the measurement to specific process conditions.
Product calibration is an additional calibration procedure to a
standard calibration.

NOTE: The product calibration is possible for DO values
in the range of 2 to 55 %-vol (20 – 550 mbar pO

).

2

A product calibration is performed as follows:

1) Power and connect the VisiWater DO sensor to ArcAir
via RS485 Converter and power supply.

2) Select the desired sensor from the sensor list

3) Go to «Process Settings»

4) Click «Start» to start the product calibration wizard

5) Follow the instruction on the screen

NOTE: Alternatively, the product calibration may be
performed with a field device on side the measuring point.

7.5 Cleaning

This chapter outlines a manual cleaning procedure for the care
and maintenance of optical dissolved oxygen (ODO) sensors
including a procedure for the cleaning the sensing membrane in
particular.

Cleaning the Sensor

Carry out the cleaning procedure as follows:

1) Remove sensor from the measuring setup.

2) Check if the ODO Cap is mounted firmly on the shaft.

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25Operating Instructions VisiWater

TROUBLESHOOTING TROUBLESHOOTING

3) Soak a dust-free cloth or tissue paper with water and wipe
the wetted parts with it. Thoroughly rinse the wetted parts
and the sensing membrane with deionised water afterwards.

4) Dry the wetted parts with a clean dust-free cloth or tissue
and store the sensor in dry and dark conditions (ODO Caps
are light-sensitive).

5) If the sensing-membrane on the front of the cap is
contaminated with oil, grease or other organic matter, soak
a clean dust-free cloth with isopropyl alcohol. Rinse residual
isopropyl alcohol immediately from the membrane with
deionised water and gently wipe over the membrane.

6) After cleaning always perform a new calibration before
carrying out measurements. (See chapter 7.3 in the
corresponding Operating Instruction Manual)

ATTENTION! Cleaning, assembly and maintenance
should be performed by personnel trained in such
work. Do not use any abrasive tissues or cleaning
materials and do not use any cleaning chemicals other
then described above. Before removing the sensor
from the measuring setup, always make sure that the
setup is pressure-less and cold and that no process
medium can be accidentally spilled. When removing
and cleaning the sensor, it is recommended to wear
safety glasses and protective gloves.

8 Troubleshooting

8.1 Sensor Self-Diagnostic

VisiWater DO sensors provide a self-diagnostic functionality to
detect and identify the most common sensor malfunctions.
Both interfaces, analog 4–20 mA or digital Modbus, may provide
warning and error messages. The analog 4–20 mA interface can
be configured according to the NAMUR recommendations to
indicate an abnormal event (See Chapter 5.2.7). Use ArcAir for
monitoring the sensor status and for troubleshooting. The follow­ing types of messages are provided by the self-diagnosis function.

NOTE: Errors cannot be ignored and corrective action

is immediately necessary.

NOTE: Warnings can be ignored but the warning will
be displayed continuously until the corrective action is
successfully completed.

NOTE: For additional information about the sensor
status and the diagnostics features refer to the sensor
operation instruction manual or the programmer`s manual.

8 .1 .1 W a r n i n g s

Warning Cause / Solution

DO reading below The oxygen reading is too low
lower limit (DO < 0%-sat). Make a new zero-point
calibration (Chapter 7.3.2).

DO reading above The oxygen reading is too high
upper limit (DO > 500 %-sat). Make a new calibration
in oxygen saturated medium. (See
chapter 7.3.3). If not successful, replace
the sensor cap.

DO reading unstable If continuously happening, use a new
cap or check the process regulation.
If the problem still appears, call our
Technical Support.

T reading below The temperature is below the user defined
lower limit measurement temperature range. If the
process temperature is outside this range,
the sensor will not perform DO readings.

T reading above The temperature is above the user
upper limit defined measurement temperature range.
If the process temperature is outside this
range, the sensor will not perform DO
readings.

Measurement The measurement interval is set to 0 or
not running the measurement temperature is out of
the range.

DO calibration Per form a calibration in order to ensure
recommended reliable measurement (Chapter 7.3).

DO last calibration The last calibration failed. The sensor is
not successful using the old successful calibration values.
In order to ensure reliable measurement
perform a new calibration (Chapter 7.3).

DO replace Replace the ODO Cap and calibrate the
sensor cap sensor cap sensor cap sensor. This
warning remains active as long as the
sensor quality is below 35%. Make sure
that after new cap replacement the
sensor reaches at least 60% cap quality.
See chapter 7 for replacement conditions.
The quality indicator takes sensor and
cap into account.

4–20 mA value The measurement value is below the
below 4 mA lower limit of the 4–20 mA interface
output. Reconfigure the 4–20 mA interface
(Chapter 5.2.7).

4–20 mA value The measurement value is above the
above 20 mA upper limit of the 4–20 mA interface
output. Reconfigure the 4–20 mA interface
(Chapter 5.2.7).

4–20 mA current The 4–20 mA interface is not able to
set-point not met regulate the current requested for the
current measurement value according to
your 4–20 mA interface configuration.
Check the 4–20 mA wiring and supply
voltage (Chapter 5.3.4).

Sensor supply The sensor supply voltage is too low for
voltage too low the sensor to operate correctly. Ensure
stable supply voltage within the sensors
specifications.

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27Operating Instructions VisiWater

TROUBLESHOOTING DISPOSAL • ORDERING INFORMATION

Warning Cause / Solution

Sensor supply The sensor supply voltage is too high for
voltage too high sensor to operate correctly. Ensure stable
supply voltage within the sensors
specifications.

8.1. 2 E r ro r s

Errors (failures) Cause / Solution

DO reading failure Sensor cap is missing or the sensor is
broken.

) exceeds Measured partial pressure of oxygen is

DO p(O

2

air pressure higher than the air pressure set by the
operator. Reconfigure the air pressure
parameter (Chapter 5.2.4).

T sensor defective The internal temperature sensor is defect,
please call our Technical Support.

DO sensor The DO sensor cap has been removed.
cap missing Do not immerse the sensor in a
measurement solution. Mount an ODO
Cap and calibrate the sensor prior
measurement (Chapter 7.2).

Red channel failure Measurement channel failure. Please
call our Technical Support.

Sensor supply The sensor supply voltage is below 6 V.
voltage far too low Please check your power supply.

Sensor supply The sensor supply voltage is above 40 V.
voltage far too high Please check your power supply.

Temperature reading The measured temperature is below the
far below min operation temperature.

Temperature reading The measured temperature is above the
far above ma x operation temperature.

Decontaminate the VisiWater DO sensor and remove health haz­ards, such as radiation, hazardous chemicals, infectious agents
etc. Provide complete description of any hazardous materials that
have been in contact with the sensor.

9 Disposal

The design of Hamilton sensors optimally consid­ers environmental compatibility. In accordance with
the EC guideline 2012/19/EU Hamilton sensors that

are worn out or no longer required must be sent to
a dedicated collection point for electrical and electronic devices,
alternatively, must be sent to Hamilton for disposal. Sensors must
not be sent to an unsorted waste disposal point.

有害物質表，請參閱www.hamiltoncompany.com,

章節過程分析，符合性聲明

10 Ordering Information

Parts below may only be replaced by original spare parts.

10.1 VisiWater DO Sensor

8.2 Getting Technical Support

If a problem persists even after you have attempted to correct it,
contact Hamilton`s Customer Support: Please refer to the contact
information at the back of this operating instruction.

8.3 Returning VisiWater DO sensor for Repair

Before returning a VisiWater DO sensor to Hamilton for repair,
contact our Customer Service (see Chapter 8.2) and request a
Returned Goods Authorization (RGA) number.

Do not return a VisiWater DO sensor to Hamilton without an RGA
number. This number assures proper tracking of your sensor.
VisiWater DO sensors that are returned without an RGA number
will be sent back to the customer without being repaired.

Ref Description Shaft Material /
Wetted Parts

243650 VisiWater DO Stainless steel 1.4435
Arc 120 FC10* 4-20 mA, Modbus

243515 ODO Cap H0 Stainless steel 1.4435
Silicone (FDA compliance
and USP Class VI approved)

243505 ODO Cap H2 Stainless steel 1.4435
PTFE (USP Class VI
approved)

10066566 VisiWater DO P PVC
Arc FC10* 4-20 mA, Modbus

243536 ODO Cap H20 PPA (Cycloaliphatic
polyamide)
Silicone (FDA compliance
and USP Class VI approved)

* FC10 = 10 m fix cable

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29Operating Instructions VisiWater

ORDERING INFORMATION

10.2 Accessories

Ref Product Name

242411 USB RS485 Modbus Converter

Description: Designed for wired communication between
ArcAir and VisiWater DO fix cable sensor.

10.3 Ser vices

Hamilton service engineers are available in Europe and China
in order to provide customers with on-site services. Hamilton
offers a wide range of services from technical support to initial
operation, qualification and maintenance of the sensors. Various
tailored services are offered for various industries. Experienced
service engineers ensure an optimal and professional service.

NOTES

Online service

Technical support

Initial Operation/Calibration

Qualification (IQ/OQ)

Service packages

Maintenance

Training

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31Operating Instructions VisiWater

Web: www.hamiltoncompany.com
USA: 800-648-5950

Europe: [phone]

© 2018 Hamilton Bonaduz AG. All rights reserved.

624821/02 — 12/2 018

Hamilton Americas & Pacific Rim

4970 Energy Way
Reno, Nevada 89502 USA
Tel: [phone]
Fax: [phone]
[e-mail]

Hamilton Europe, Asia & Africa

Via Crusch 8
CH-7402 Bonaduz, Switzerland
Tel: [phone]
Fax: [phone]
[e-mail]

To find a representative in your area, please visit www.hamiltoncompany.com.

This guide may be available in other languages.
Visit www.hamiltoncompany.com for more information.