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© ABB Group September 1, 2014 | Slide 1 4690 Turbidity Systems Accurate, reliable turbidity measurement
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© ABB Group September 1, 2014 | Slide 2 ABB’s Range of Turbidity Sensing Systems In-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
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© ABB Group September 1, 2014 | 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
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© ABB Group September 1, 2014 | 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. 1 2 3 4 5
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© ABB Group September 1, 2014 | Slide 5 Principle of Operation Nephelometric 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 Light Source Lens Detector Scattered light is measured at a 90° angle to the incident beam
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© ABB Group September 1, 2014 | Slide 6 Choice of Both ISO and EPA Compliant Sensors Suitable for regulatory monitoring EPA 1 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 ISO 2 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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© ABB Group September 1, 2014 | Slide 7 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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© ABB Group September 1, 2014 | Slide 8 Flow-Through Sensor Design Fast 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
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© ABB Group September 1, 2014 | Slide 9 Automatic Cleaning of Optical Cell Reduces 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
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© ABB Group September 1, 2014 | Slide 10 Dry Secondary Calibration Standard Simplifies 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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© ABB Group September 1, 2014 | Slide 11 Patented User Replacement Bulb Design Allows 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
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© ABB Group September 1, 2014 | Slide 12 Low Maintenance Minimises cost of ownership TaskRecommended frequency Visual check - check sample flow, check for any leaksWeekly Calibration verification 1 with secondary standard 2 Monthly Calibration 2 with primary standard 4 – as per regulatory guidelines Quarterly* Wiper blade replacementQuarterly “White Light” source (EPA 180.1) replacementAnnually “Infrared” LED source (ISO 7027) replacementEvery 5 years 1 Calibration verification means a procedure used to check whether or not the calibration of the instrument is within certain limits 2 Secondary 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 formazin 3 Calibration means a procedure which checks or adjusts an instruments accuracy by comparison with a defined standard or reference 4 Primary 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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© ABB Group September 1, 2014 | Slide 13 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
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© ABB Group September 1, 2014 | Slide 14
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