YOKOGAWA DO70G User manual

User’s
Manual
Model DO70G
Optical Dissolved Oxygen Sensor
IM 12J05D04-01E
IM 12J05D04-01E
8th Edition

i
IM 12J05D04-01E
uIntroduction
The DO70G optical dissolved oxygen sensor uses the optical (uorescence) measurement
method to continuously measure oxygen dissolved in water
Topics and information that need your special attention in handling the product are given in the
text of this manual along with cautionary notes, such as a warning or caution, depending on
their importance. Strictly observe these items from the standpoint of safety and prevention of
equipment damage. For a notation, such as a warning also indicated on the product, there is an
alert mark in the manual.
1. ConrmingtheSpecications
The DO70G sensor cable should have the specied length. The crimp-on terminals are either
pin-type or M4 ring-type.
Upon arrival of the purchased product, carefully unpack it and make sure the product has not
been damaged during transportation.
Verify the model code on a name plate adhered on the packaging box. For details of the model
code, see subsection 1.2.2.
2. InformationCoveredbyThisManual
This manual covers all of the information on handling the DO70G optical dissolved oxygen
sensor, such as instructions on installation, inspection, and maintenance and service.
Note : In this manual, descriptions of the basic system assumes that the DO402G Dissolved Oxygen Converter or FLXA402 4-Wire
Converter is used.
Refer to the instruction manual for information on the converter connecting holders with the
DO70G and how to connect sensor cables.
Note that the instruction manuals listed in the following table are for the associated equipment
used with the EXA DOTM Dissolved Oxygen Metering System.
ManualsforAssociatedEquipmentUsedwiththeEXADODissolvedOxygenMeteringSystem
Model TitleofManual Manual No.
DO402G Dissolved Oxygen Converter IM 12J05D02-01E
FLXA402 4-Wire Converter IM 12A01F01-02EN
IM 12A01F05-01EN etc
DO70G Optical Dissolved Oxygen Sensor IM 12J05D04-01E (This manual)
DOX10 Power Supply Unit IM 12J05S01-01E
PB350G Angled Floating Ball Holder IM 19H1E1-01E
PB360G Vertical Floating Ball Holder IM 19H1E2-01E
DOX8HS Submersion Type Holder (Style B) IM 19H1D2-01E
Note: Only the basic system of basic components are listed on the front panel.
Refer to respective instruction manual for information on recorders, annunciators and other instruments.
An exclusive User’s Manual might be attached to the products whose su󰀩x codes or option
codes contain the code “Z” (made to customers’ specications). Please read it along with this
manual.
n TrademarkNotices
• EXA DO, FLXA are trademarks of Yokogawa Electric Corporation.
• All other company and product names mentioned in this user’s manual are trademarks or
registered trademarks of their respective companies.
• We do not use TM or ® mark to indicate those trademarks or registered trademarks in this
user’s manual.
No. IM 12J05D04-01E 8th Edition: July 2023 (YK)
All Rights Reserved Copyright © 2012, Yokogawa Electric Corporation
8th Edition : July 11, 2023

ii
IM 12J05D04-01E
uSafety Precautions
n SafetyandModicationPrecautions
• In order to protect the system controlled by the product and the product itself and ensure
safe operation, observe the safety precautions described in this user’s manual. We assume
no liability for safety if users fail to observe these instructions when operating the product.
• If this instrument is used in a manner not specied in this user’s manual, the protection
provided by this instrument may be impaired.
• If any protection or safety circuit is required for the system controlled by the product or for
the product itself, prepare it separately.
• Be sure to use the spare parts approved by Yokogawa Electric Corporation (hereafter
simply referred to as YOKOGAWA) when replacing parts or consumables.
• Modication of the product is strictly prohibited.
• The following safety symbols are used on the product as well as in this manual.
WARNING
This symbol indicates that an operator must follow the instructions laid out in this manual in order
to avoid the risks, for the human body, of injury, electric shock, or fatalities. The manual describes
what special care the operator must take to avoid such risks.
CAUTION
This symbol indicates that the operator must refer to the instructions in this manual in order to
prevent the instrument (hardware) or software from being damaged, or a system failure from
occurring.
CAUTION
This symbol gives information essential for understanding the operations and functions.
NOTE
This symbol indicates information that complements the present topic.
n NotesonHandlingUser’sManuals
• Please hand over the user’s manuals to your end users so that they can keep the user’s
manuals on hand for convenient reference.
• Please read the information thoroughly before using the product.
• The purpose of these user’s manuals is not to warrant that the product is well suited to any
particular purpose but rather to describe the functional details of the product.
• No part of the user’s manuals may be transferred or reproduced without prior written
consent from YOKOGAWA.
• YOKOGAWA reserves the right to make improvements in the user’s manuals and product at
any time, without notice or obligation.
• If you have any questions, or you nd mistakes or omissions in the user’s manuals, please
contact our sales representative or your local distributor.
nProduct Disposal:
The instrument should be disposed of in accordance with local and national legislation/
regulations.
8th Edition : July 11, 2023

iii
IM 12J05D04-01E
uAfter-sales Warranty
lDo not modify the product.
l During the warranty period, for repair under warranty carry or send the product to the local
sales representative or service o󰀩ce. Yokogawa will replace or repair any damaged parts and
return the product to you.
l Before returning a product for repair under warranty, provide us with the model name and
serial number and a description of the problem. Any diagrams or data explaining the problem
would also be appreciated.
l If we replace the product with a new one, we won't provide you with a repair report.
l Yokogawa warrants the product for the period stated in the pre-purchase quotation. Yokogawa
shall conduct dened warranty service based on its standard. When the customer site is
located outside of the service area, a fee for dispatching the maintenance engineer will be
charged to the customer.
l In the following cases, customer will be charged repair fee regardless of warranty period.
• Failure of components which are out of scope of warranty stated in instruction manual.
• Failure caused by usage of software, hardware or auxiliary equipment, which Yokogawa did
not supply.
• Failure due to improper or insu󰀩cient maintenance by user.
• Failure due to abuse, misuse or modication which Yokogawa does not authorize.
• Failure due to power supply (voltage, frequency) being outside specications or abnormal.
• Failure caused by any usage out of scope of recommended usage.
• Any damage from re, earthquake, storms and oods, lightning, disturbances, riots, warfare,
radiation and other natural changes.
l Yokogawa does not warrant conformance with the specic application at the user site.
Yokogawa will not bear direct/indirect responsibility for damage due to a specic application.
l Yokogawa will not bear responsibility when user congures the product into systems or resells
the product.
l Maintenance service and supplying repair parts will be covered for ve years after the
production ends. For repair for this product, please contact the nearest sales o󰀩ce described
in this instruction manual.
8th Edition : July 11, 2023

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IM 12J05D04-01E
<CONTENTS> v
Model DO70G
Optical Dissolved Oxygen Sensor
CONTENTS
uIntroduction....................................................................................................i
uSafety Precautions .......................................................................................ii
uAfter-sales Warranty ...................................................................................iii
1. General ...................................................................................................... 1-1
1.1 Features ............................................................................................................. 1-1
1.2 Components ...................................................................................................... 1-1
1.3 StandardSpecications................................................................................... 1-2
1.4 ModelandSu󰀩xCodes ................................................................................... 1-3
1.5 ExternalViewandDimensions........................................................................ 1-4
2. InstallingtheSensorandConnectingtheCable .................................. 2-1
2.1 Preparing for Installation ................................................................................. 2-1
2.2 Installation ......................................................................................................... 2-2
2.2.1 Selecting the Measurement Point ...................................................... 2-2
2.2.2 Selecting the Sensor Holder .............................................................. 2-3
2.2.3 Installing the Sensor in the Holder ..................................................... 2-4
2.3 ConnectingtheSensorCable.......................................................................... 2-4
3. SettingandCalibratingtheConverter ................................................... 3-1
4. Maintenance.............................................................................................. 4-1
4.1 Routine Inspection............................................................................................ 4-1
4.2 Inspection If Failure Occurs............................................................................. 4-1
4.3 Maintenance Parts ............................................................................................ 4-2
RevisionInformation ...............................................................................................i
IM12J05D04-01E8thEdition
8th Edition : July 11, 2023

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<1. General> 1-1
IM 12J05D04-01E
1. General
Do not drop the sensor. Please handle it with care.
1.1 Features
• Longstability
The sensor will be ready for measurement approximately 10 minutes after turning on the
power.
The sensor can be used continuously and stably for a long time thanks to the stain-resistant
sensor cap and the measurement method which is less susceptible to disturbance. It also is
hardly inuenced by air bubbles in the measurement liquid.
• Highlyreliablemeasurementsystemwithlowmaintenance
The sensor withstands a pressure of up to 500 kPa. It can be assembled into the
submersion type, angled oating ball, or vertical oating ball holders.
In the submersion type holder, the sensor can be automatically cleaned with jet-sprayed
water or air at regular intervals. By selecting a suitable holder and cleaning device for
applications, a highly reliable, low-maintenance measurement system can be built with this
sensor.
• Easymaintenance
The sensor cap ages with time and eventually comes to the end of its service life. Before
this happens, replace it with a new one. The sensor cap is easily replaced
1.2 Components
Sensor Cap
Sensor Cable
O-ring for Adaptor
(EPDM) The detected signal travels through the cable
to the dissolved oxygen converter.
Sensor cable is specified by the model of converter:
DO402G or FLXA402. See the section 1.4.
CAUTION
Do not loosen the sensor cap except in time of replacement.
8th Edition : July 11, 2023

<1. General> 1-2
IM 12J05D04-01E
1.3 StandardSpecications
Object of Measurement:
Concentration of oxygen dissolved in sewage and drainage (water);
cannot be used with organic solvents.
Principle of Measurement: Optical (uorescence) measurement method
Measurement Range: 0 to 25 mg/L
Note: The measurement range must be entered through the dissolved oxygen converter.
Temperature of Measurement water: 0 to 50 °C
Flow rate: 2 m/sec or less
Pressure: 0 to 500 kPa
Resistance Temperature Detector (RTD): NTC 22k
Construction:
Sensor unit: Stainless steel (316L SS)
O-ring: Ethylene Propylene Rubber (EPDM)
Permeable membrane: Silicone resin
Cable shielding: Heat-resistant exible PVC
Sensor Cable:
For code -03E, -05E, -10E
Length; 3 m, 5 m, 10 m
Terminal shape;
pin (for converter),
M4 Ring (for power supply unit)
For code -05D, -10D, -15D, -20D
Length; 5 m, 10 m, 15 m, 20 m
Terminal shape; pin
Weight:
Sensor; Approx. 0.1 kg
Cable;
For -��E: Approx. 0.1 kg/m + 0.1 kg
For -��D: Approx. 0.8 kg/m + 0.8 kg
Power supply
DO402G; from DOX10 Power Supply Unit
FLXA402; from FLXA402
• The DOX10 may not be used depending on the relevant standard of your region.
Use a power supply that meets the following specications.
• Use a power supply that is appropriate for the relevant standard in your region.
• Use a power supply with an output voltage in the range of 24 V DC ± 10% and power consumption of 1 W or higher.
• For wiring the DO70G, connect the input and output cables of the 24 V power supply by separating them by a minimum
spatial distance of 3 mm and creepage distance of 6 mm.
[Characteristics](whenconverteriscombinedwithDO70G)
Repeatability: 0.1 mg/L or 3% FS, whichever is greater
Temperature Compensation Error:
Within ±3% FS for a ±5°C change in the range of 0 to 40°C
Response Time : Within 2 minutes (90% response at the time of the sensor’s
immersion in 2 wt% sodium sulte solution after the immersion in
air-saturated water)
8th Edition : July 11, 2023

<1. General> 1-3
IM 12J05D04-01E
1.4 ModelandSu󰀩xCodes
lDO70G Optical Dissolved Oxygen Sensor
Model Su󰀩xCode Option Code Description
DO70G ···························· ··················· Optical dissolved oxygen sensor (*1)
Insert length -120 ··················· 120 mm
Type -E ··················· Always -E
Cable length -00N
-03E
-05E
-10E
-05D
-10D
-15D
-20D
···················
···················
···················
···················
···················
···················
···················
···················
No cable
3 m (*2)
5 m (*2)
10 m (*2)
Digital 5 m (*3)
Digital 10 m (*3)
Digital 15 m (*3)
Digital 20 m (*3)
−-N ··················· Always -N
Option /SCT Stainless steel tag plate
*1: When using DO70G with DOX8HS/PB350G/PB360G, a dedicated adaptor is required.
When ordering DO70G with the holder, refer to the combination table below and select an adaptor according to the Holder Option
Code.
If you order only DO70G, please make a separate order for the adaptor by Part No. in the table below. However, if you are
already using DOX8HS/PB350G/PB360G and DO70G, you can use the existing adaptor.
In this case, you do not need to make an additional order for the adaptor.
Holder-AdaptorCombination
Holder Model Holder Option Code Part No.
Submersion Type Holder
DOX8HS
/D72S (Stainless Steel, Holder material: -S3) K9148NA
/D72P (Polypropylene, Holder material: -PP) K9148NB
Slant Type Float Holder
PB350G
/D72 (Polypropylene) K9679CA
Vertical Type Float Holder
PB360G
/D72 (Polypropylene) K9679CA
*2: The power cable is +1.5 m (Refer to 1.5 External View and Dimensions).
For connection to DO402G
*3: For connection to FLXA402
lMaintenance Parts
Please refer to 4.3 Maintenance Parts.
8th Edition : July 11, 2023