© ABB Group April 11, 2023 | Slide 1

4690 Turbidity SystemsAccurate, reliable turbidity measurement

© ABB Group April 11, 2023 | Slide 2

ABB’s Range of Turbidity Sensing SystemsIn-line flow-through and in-situ dip sensors

4690 Range A range of flow-through turbidity

systems available with optional auto-cleaning for reduced maintenance

EPA180.1 & ISO 7027 compliant designs based on light scatter

Ranges available to measure up to 400 NTU

4670 Range A range of flow-through and in-situ dip

sensors with auto-cleaning for reduced maintenance

Measures light absorption to calculate turbidity value

Ranges available to measure up to 2000 FTU

All systems available with dry secondary calibration standards for reduced cost of ownership

© ABB Group April 11, 2023 | Slide 3

4690 Turbidity Range For the measurement of turbidity in drinking water

Turbidity is a critical measurement in drinking water -indicates water quality and filtration effectiveness

ABB’s 4690 range of turbidity systems offer reliable, accurate turbidity measurement with low cost of ownership

Suitable for turbidity measurement throughout the drinking water plant

© ABB Group April 11, 2023 | Slide 4

Accurate, Reliable Turbidity Measurement Throughout the drinking water plant

1. Raw Water/Source Monitoring

Provides an indication of the solids loading entering the treatment plant to enable adjustment of the coagulant dose.

2. Monitoring clarified water

Clarifier supernatant turbidity measurement monitors clarifier efficiency to provide early warning of floc blanket break-up or incorrect coagulant dosing.

3. Filter backwashing control

Monitors filter backwash curve to minimize clean water usage.

4. Monitoring of filtered water

Ensures correct operation of the filters and guards against turbidity breakthrough.

5. Monitoring of final drinking water quality

Provides a final quality check after disinfection before distribution.

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Principle of OperationNephelometric measurement

The 4690 range of turbidity sensors utilize a nephelometric design

Light passes through the sample where it is scattered by any suspended particles

such as silt, clay, algae, organic matter, microorganisms, colloidal material, and large dissolved molecules

This scattered light is measured by a detector that is located at a 90° angle to the incident beam

Detector response correlates to turbidity

A higher level of scattered light reaching the detector results in a higher turbidity value

Ultralow back-scatter allows for very accurate readings as only light scattering due to turbidity is measured

Light is scattered by suspended particles in the water

Ligh

tLight

Source

Lens

Lens

Detector

Scattered light is measured at a 90° angle to the incident beam

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Choice of Both ISO and EPA Compliant SensorsSuitable for regulatory monitoring

EPA1 Compliant Sensor

EPA 180.1 compliant sensor uses a “White Light”

White light sensor is good for low level turbidity measurement

Suitable for US EPA reporting of filtered water

ISO2 Compliant Sensor

ISO 7027 compliant sensor uses a “Near Infrared LED”

The wavelength (860-890nm) is less susceptible to color interferences

Good for both low level turbidity measurement and for measuring samples with color

1 United States Environmental Protection Agency

2 International Organization for Standardization

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4690 Turbidity Systems Product overview

Wall- or panel-mounted transmitters available

Easy-to-use, ultra-stable electronics with in-built digital filters for bubble rejection

Auto-clean system

Programmable automatic cleaning reduces maintenance and ensures sensor accuracy and reliability

Dry Standard Standards

Simplifies routine instrument verification, eliminates chemical standard preparation errors and reduces cost of ownership

Sample Flow Cell

Flow-through nephelometric design with minimal sample residence time provides fast response to turbidity changes for improved process control

Integral Sample Feed & Drain Valves

Provides simple installation and quick and easy calibration

Emitter & Receiver Assemblies

EPA180.1 or ISO 7027 Compliant design

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Flow-Through Sensor DesignFast response and reduced maintenance

Fast Response Time

Minimal sample residence time allows fast response time to process changes

Typically 90% step change in <45 seconds

Up to 75% faster response time than some competitor turbidity designs

Offers improved process control

Reduced Maintenance

Flow-through design does not act as a “sediment trap”

Removes requirement for manual cleaning of settled particles in the sensor body

Reduces cost of ownership

© ABB Group April 11, 2023 | Slide 9

Automatic Cleaning of Optical CellReduces maintenance and ensures accuracy

Optical cell fouling greatly reduces accuracy of turbidity measurement

ABB’s 4690 Sensors feature an Auto-clean system that overcomes the problem of optical cell fouling

Mechanical wiper assembly physically wipes clean the optical cell at user-programmable intervals

No need to regularly disassemble the sensor to inspect/manually clean the photocell window

Reduces maintenance and lowers cost of ownership whilst ensuring accuracy and reliability

© ABB Group April 11, 2023 | Slide 10

Dry Secondary Calibration StandardSimplifies routine instrument verification

Optomechanical filter that diverts a fixed quantity of light to the detector corresponding to a known turbidity value

Each secondary standard is factory calibrated and certified against a primary formazine standard

Quick & simple verification/calibration procedure that minimizes instrument downtime

Reduces cost of ownership by reducing chemical standards and the time taken on-site to prepare such standards

Minimise employee’s exposure to Formazine which is highly toxic and a suspected carcinogen

Simple to use, repeatable and reliable

Insert directly into sensor body during calibration procedure

Available in different turbidity concentrations to suit the application

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Patented User Replacement Bulb DesignAllows lamp replacement in under a minute

Changing incandescent bulbs to ensure peak performance used to be a laborious process

With ABB’s replacement bulb design you can throw those cotton gloves away!

Each bulb is supplied fully protected in a patented assembly with integral light guide

No direct contact with the bulb

Ensures maximum lamp life

No threading of wiring

No waiting for the bulb to cool

Simply plug and play

© ABB Group April 11, 2023 | Slide 12

Low MaintenanceMinimises cost of ownership

Task Recommended frequency

Visual check - check sample flow, check for any leaks Weekly

Calibration verification1 with secondary standard2 Monthly

Calibration2 with primary standard4 – as per regulatory guidelines

Quarterly*

Wiper blade replacement Quarterly

“White Light” source (EPA 180.1) replacement Annually

“Infrared” LED source (ISO 7027) replacement Every 5 years

1Calibration verification means a procedure used to check whether or not the calibration of the instrument is within certain limits2Secondary standard means a standard that the manufacturer has certified will give instrument calibration results equivalent to the results obtained when the instrument is calibrated with primary standard such as formazin3Calibration means a procedure which checks or adjusts an instruments accuracy by comparison with a defined standard or reference4Primary standard means a standard, such as formazin, used to calibrate the instrument response with respect to analyte concentration

*Based on EPA guidelines for individual filter effluent

All service tasks can be quickly and easily performed on site without the need for a skilled technician

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4690 Turbidity Systems Accurate, reliable turbidity measurement

Flow-through turbidity design Fast response to process turbidity

changes due to minimal sample residence time

Choice of EPA or ISO compliant methods

Automatic sensor cleaning Reduces maintenance requirements Optimises performance sensitivity

Dry secondary calibration standard Accurate, repeatable, simple, safe Realise significant cost savings by

reducing the use of primary standards

Simple to use and maintain Intuitive, user-friendly design Simple-to-perform annual service

Reliable and accurate measurement Ultralow back scatter for accurate

measurement of low turbidity values Automatic bubble rejection to

compensate for erroneous readings due to degassing

© ABB Group April 11, 2023 | Slide 14