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Digital nitrate or SAC sensor Viomax CAS51D

Memosens sensor for optical measurement of nitrate, SAC, CODeq, TOCeq, BODeq or DOCeq

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Digital nitrate or SAC sensor Viomax CAS51D

Memosens sensor for optical measurement of nitrate, SAC, CODeq, TOCeq, BODeq or DOCeq

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Benefits

  • Cost-effective: Easy, chemical-free handling is safe, environmentally friendly and saves on operational expenditure.
  • Extremely fast response time: Measured value processing in the sensor provides reliable real-time process information.
  • Fast and easy commissioning: Sensor comes precalibrated and preconfigured ex factory.
  • Enables unattended plant operation: Intelligent design and automatic air-cleaning functionality maximize availability and minimize maintenance.
  • Perfect adaption to open basins: Fast and flexible sensor positioning with Flexdip CYH112 holder and CYA112 assembly system.
  • Perfect adaption to pipes: Various flow cells allow easy plant integration.

Integrated technologies

Memosens technology
Liquiline: cutting-edge transmitter platform
FLEXible answers to individual needs
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Digital nitrate or SAC sensor Viomax CAS51D

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Manufacturer's warranty

Engineered for confidence

Our instruments are designed for long‑lasting performance, precise measurement, and dependable operation in demanding industrial environments. Each product includes a standard manufacturer’s warranty that reflects our commitment to quality and to the trust you place in our solutions.

Should a warranty case occur, the device will be assessed and the applicable remedy will be provided in line with the warranty terms – helping ensure a reliable and efficient resolution and supporting continued operation of your measurement point.

Request for extended warranty

If you require extended warranty coverage, simply contact your local Endress+Hauser representative. Our experts will advise you on the available options to match your application and risk profile, helping you protect your investment, reduce unexpected repair costs, and ensure reliable long‑term operation beyond the manufacturer's warranty period.

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Warranty terms apply

The manufacturer's warranty and extended warranty are subject to specific conditions. For full details, please refer to the locally applicable General Terms and Conditions (GTC), which can be found on the respective country page of our website.

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Endress+Hauser’s qualified service engineers ensure your measurement devices are commissioned right the first time, delivering application‑aligned accuracy, regulatory compliance, and operational confidence from startup onwards, anywhere in the world.

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With Endress+Hauser Smart Support, you benefit from faster issue resolution, higher uptime, reliable global expertise across the entire product lifecycle – and lasting peace of mind.

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With deep field expertise, harmonized processes, and continuous monitoring, we accompany you with comprehensive service offerings – from initial start‑up through instrumentation maintenance to process optimization – as a true lifetime partner delivering improved outcomes.

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By choosing the Liquiline platform, you’re effectively choosing to spend less money on stock holding, save installation time and gain operational safety!

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Product information

Viomax CAS51D - the smart nitrate & SAC sensor with fast response time and chemical-free handling.
Digital nitrate and SAC sensor
Specifications
Measuring / Application task Analyser
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Description

Viomax CAS51D is a smart sensor that allows unattended operation in a wide range of process conditions in water, wastewater and utilities. It ensures continuous online measurements without any chemicals and it is extremely robust as well as low-maintenance thanks to its self-cleaning design. You can select the CAS51D as nitrate sensor or as sensor for SAC and several sumparameters. Thanks to Memosens digital technology, Viomax CAS51D offers high process and data integrity and is easy-to-use.

Field of application

Viomax CAS51D measures nitrate, SAC or several sum parameters in drinking water, process water and wastewater applications as well as in the utilities sector:

  • Organic load or nitrate in inlet and outlet
  • Determination of CODeq, TOCeq, BODeq or DOCeq
  • Monitoring, control and optimization of treatment processes
  • Nitrate monitoring in the aeration basin and denitrification stage
Benefits
  • Cost-effective: Easy, chemical-free handling is safe, environmentally friendly and saves on operational expenditure.
  • Extremely fast response time: Measured value processing in the sensor provides reliable real-time process information.
  • Fast and easy commissioning: Sensor comes precalibrated and preconfigured ex factory.
  • Enables unattended plant operation: Intelligent design and automatic air-cleaning functionality maximize availability and minimize maintenance.
  • Perfect adaption to open basins: Fast and flexible sensor positioning with Flexdip CYH112 holder and CYA112 assembly system.
  • Perfect adaption to pipes: Various flow cells allow easy plant integration.
Predecessors
Stamosens CSS70, Stamosens CNS70
Downloads
Most downloaded
Technical Information (TI)
TI Viomax CAS51D Photometric sensor for measuring the spectral absorption coefficient or
nitrate content
English version - 09/2024
Download
Operating Instruction (BA)
BA Viomax CAS51D Photometric sensor for SAC or nitrate measurement
English version - 09/2024
Download
Operating Instruction (BA)
Operating Instructions - Compressed air cleaning unit - 115VAC Operating Instructions - Compressed air cleaning unit - 115VAC
English version - 01/2013
Download
The CAD Drawings will be available after the configuration.
All downloads
418 Downloads
Technical Information (TI)
Most downloaded
TI Viomax CAS51D Photometric sensor for measuring the spectral absorption coefficient or
nitrate content
English version - 09/2024
Download
Operating Instruction (BA)
Most downloaded
BA Viomax CAS51D Photometric sensor for SAC or nitrate measurement
English version - 09/2024
Download
Operating Instruction (BA)
Operating Instructions - Compressed air cleaning unit - 115VAC Operating Instructions - Compressed air cleaning unit - 115VAC
English version - 01/2013
Download
Installation Instructions (EA)
EA CYR51 mechanical cleaning Spare parts kits
English version - 04/2026
Download
Installation Instructions (EA)
EA Kit Flow cell CAS51D Instruction Kit Flow cell CAS51D
English version - 07/2025
Download
Installation Instructions (EA)
EA CAV01 kit, seal set for the CAV01 flow assembly
English version - 08/2023
Download
Special Documentation (SD)
SD for CAY342 and CAY451 for preparing stock solutions SD for CAY342 and CAY451 for preparing stock solutions
English version - 01/2026
Download
Fields of Activities (FA)
Sensors, transmitters, compact devices and assemblies Experts in Liquid Analysis
English version - 02/2026
Download
Fields of Activities (FA)
Analizzatori, sensori in loco e campionatori Esperti nell'analisi dei liquidi
Italian version - 11/2018
Download
Fields of Activities (FA)
水質分析の専門知識 センサからすべてを備えた
ターンキーソリューションまで
Japanese version - 06/2025
Download
Fields of Activities (FA)
Esperti nell’analisi dei liquidi Dai sensori singoli a soluzioni
complete “chiavi in mano”
Italian version - 01/2017
Download
Fields of Activities (FA)
Kompetenz in der Flüssigkeitsanalyse Vom Sensor bis zur schlüsselfertigen Komplettlösung
German version - 09/2022
Download
Fields of Activities (FA)
Catálogo Portfolio Analítica Desde sensores hasta soluciones completas
Spanish version - 01/2017
Download
Fields of Activities (FA)
Analizzatori, sensori in loco e campionatori Esperti nell'analisi dei liquidi
Italian version - 03/2017
Download
Fields of Activities (FA)
Analyseurs, capteurs in situ et préleveurs Experts en analyses physico-chimiques
French version - 12/2023
Download
Fields of Activities (FA)
Catálogo Analizadores Analizadores, sensores y tomamuestras in situ
Spanish version - 11/2018
Download
Fields of Activities (FA)
Sıvı analizinde uzmanlık Sensörlerden komple anahtar teslim çözümlere
Turkish version - 11/2023
Download
Fields of Activities (FA)
アナライザ、現場センサおよびサンプラ 水質分析のエキスパート
Japanese version - 08/2025
Download
Fields of Activities (FA)
Expertise in liquid analysis From sensors to complete turnkey solutions
English version - 09/2022
Download
Fields of Activities (FA)
Analyzers, in-situ sensors and samplers Experts in Liquid Analysis
English version - 01/2023
Download
Fields of Activities (FA)
Sensoren, Messumformer, Kompaktgeräte and Armaturen Kompetenz in der Flüssigkeitsanalyse
German version - 02/2026
Download
Fields of Activities (FA)
Jistota v analýze kapalin Od senzorů po kompletní dodávku na klíč
Czech version - 01/2017
Download
Fields of Activities (FA)
Sensori, trasmettitori, dispositivi compatti e armature Sensori, trasmettitori,
dispositivi compatti e armature
Esperti in materia di analisi dei
liquidi
Italian version - 06/2026
Download
Fields of Activities (FA)
Endress+Hauser 水質分析計ファミリ ラインナップと事例
Japanese version - 03/2017
Download

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Spare parts and accessories

further parts
further parts

Kit CAS51D flow cell O-ring set

further parts
further parts
Order code 71352951
further parts
further parts

Spare and wear parts CYR51

further parts
further parts
Order code XPC0031-
further parts
further parts

Reagent / Standard solution CY80SI

further parts
further parts
Order code CY80SI-
further parts
further parts

Flow cell for CAS sensors CAV01

further parts
further parts
Order code CAV01-
Spare parts & accessories
Viomax CAS51D - the smart nitrate & SAC sensor with fast response time and chemical-free handling.
Digital nitrate and SAC sensor

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Digital nitrate and SAC sensor
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Spare parts and accessories

further parts
further parts

Kit CAS51D flow cell O-ring set

further parts
further parts
Order code 71352951
further parts
further parts

Spare and wear parts CYR51

further parts
further parts
Order code XPC0031-
further parts
further parts

Reagent / Standard solution CY80SI

further parts
further parts
Order code CY80SI-
further parts
further parts

Flow cell for CAS sensors CAV01

further parts
further parts
Order code CAV01-
Spare parts & accessories

Selection of compatible products

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