Turbidity/Chlorine SMART Sensor Platform

Turbidity and chlorine measurements in Water Treatment Plants

since 1959 No.1 Process analyzer supplier to Japanese market*

"Our mission is supplying clean water for all people."

“Human health and safety water is our starting point.”

"Reduce maintenance time and costs are our largest concern.”

Many of our customers face these challenges - the SENCOM™ 4.0 Platform resolves them.

*Based on a Yokogawa survey in 2019

Sustainable Water Management with Turbidity & Chlorine

Reliable and smart water management system

Yokogawa supports the entire lifecycle of their products through reliable sensing technology and data utilization. We extended SENCOM 4.0 platform to Turbidity measurement and Chlorine measurement, and it will continue to provide unique value throughout the product's entire lifecycle.

Yokogawa's next-generation Turbidity and Chlorine analyzer for smart city

To facilitate optimal processes and improve personnel efficiency, Yokogawa has placed a strong focus on our Digital SMART Sensor SENCOM 4.0 Platform. This innovative analyzer platform provides full visualization and enhanced process uptime by optimizing maintenance, reducing configuration time, and simplifying in-field maintenance and calibration.

> What is SENCOM?


About OpreX

OpreX is the comprehensive brand for Yokogawa’s industrial automation (IA) and control business and stands for excellence in the related technology and solutions. It consists of categories and families under each category. This product belongs to the OpreX Analyzers family that is aligned under the OpreX Measurement category.


The SENCOM SMART Sensor System

4-wire SMART Sensor Platform for Turbidity/Chlorine FLXA402T

Changing technologies don't have to result in negative consequences putting throughput, quality, or compliance at risk. The advanced flexibility function features multi-input, allowing the connection of up to 2 sensors at one unit.

The FLXA402T can handle new SMART sensors (Turbidity detector/Chlorine detector) and conventional pH/Conductivity sensors. SENCOM4.0 Platform allowing an easy upgrade to digital SMART sensors in the future, giving you more flexibility and optimizing your OPEX.

Learn More 

2 in 1 FLXA402T and TB820D, FC800D


 Possible sensor connection to Digital SMART SENCOM

FLXA402T and TB820D, FC800D

Turbidity Measurement

The biggest problem with the turbidity meter is the dirt on the sensor. Easy to clean cell structure, Automatic wash system, Long life time light source contribute to the reduction of maintenance costs.

Chlorine Measurement

Environmentally friendly with the right amount of chlorine injection, minimizes remote maintenance and reduce maintenance time.

pH and Conductivity Measurement

Yokogawa’s pH and Conductivity sensors are highly reliable and very unique. You can select the most valuable sensor.

pH and Conductivity sensors

Analyzer specialized for Tap water treatment process

Tap Water treatment process

Water Treatment Application

1. Sedimentation
Receiving well 
Raw water contains sand, pebbles and soil. They are removed by sedimentation in the middle of a gentle stream.
-Monitor Turbidity, pH and SC

2. Stabilization
Receiving well
The well adjust to keep the water level constant and pressure for the next process.
-Monitor Turbidity, pH and Chlorine

3. Flocculation
Flocculation basin

The raw water with the coagulant is slowly agitated ."Flock" is a group of fine sand and soil  and  gathered together by the action of a coagulant. By creating flocs, particles such as sand and soil become relatively large and easily sink.
-Monitor Turbidity and pH

Flocculation basin

4. Sedimentation
Sedimentation basin
Flocks are sunk in a quiet stream, removing sand and soil ( flocs) from the water
-Monitor Turbidity, pH

5. Sand filtration
Sand filtering
A layer of sand or gravel filters the water and removes fine particles
-Monitor Free chlorine, Turbidity

6. Chlorination
Mixing basin
Added chlorine for disinfection
-Monitor Free chlorine, Turbidity and pH

7. Clean water reservoir
Water reservoir

Store clean water in the distribution reservoir and adjust the water amount for distribution
-Monitor Turbidity , Free chlorine and pH

Water reservoir

8. Distribution pump
Send the water from the distribution reservoir to the water supply station. Water is sent to each distribution station / reservoir using water pipes and supplied to each household or facility.
-Monitor Turbidity, Free chlorine and pH

9. Distribution Tank and Piping
Distribution reservoir
Keep enough water for use
-Monitor Turbidity, Free chlorine and pH


You don't need to do any difficult setting. The FLXA402T configurations have already optimized for selected measurement when it is shipped.
FLXA 402T Multi Sensor variation 1st module TB820D FC800D FC800D FC800D FC800D TB820D TB820D 2nd module TB820D FC800D TB820D Analog pH Analog Conductivity Analog pH sensor Analo...
Maximum digit is three decimal points, default is 2 decimal points.
PH4, pH7 and pH9 tables complied by NIST, DIN and US standards are available.
The FLXA402T can connect a pH sensor, but an ORP sensor is not available. For ORP measuring, please select the FLXA402. (Not FLXA402T)
Conductivity measuring is available in the FLXA402T. For resistivity measuring, please select the FLXA402. (Not FLXA402T)
Static conductivity sensor is available. Inductive conductivity sensors are not available. For inductive conductivity sensor measuring, please select the FLXA402. (Not FLXA402T)
Yes, FLXA402T+PG400 supports ultrasonic cleaning for both Turbidity detectors.
Yes, you can use pH compensation for -F1 model. Please use this function in case of fluctuate pH value. If it is difficult to decide which is better, please fill pH fluctuation in the Inquiry Sheet and contact us. ...
Yes, 0.2μm mesh filter and 1.0μm mesh filter for TB820D are same as TB750G. You can select zero turbidity filter in case; Measuring range is 2.0 NTU or greater: 1μm Measuring range is less than 2.0 NTU: 1μm + 0.2μm ...
Maximum 20m is available. If you want to use more than 20m cable, please contact us.
No, you don’t need to do any adjustment. Just replace light source.
Yes, you can buy flow-cell and glass windows as a spare part.
We strongly recommend using head tank in any case for stable measurement. If your facility has enough pretreatment and there are no bubbles, you can install the TB820D without head tank. D1 pressurized head tank is suitable for under 2 NTU measuremen...
K9411UA and K9726EF consist of filter case and filter element. K9008ZD and K9726EG are only filter element and you can use them in case of filter replacement.
Parts No. Name Remarks QTY Recommended Replacement Period K8003DN LED ASSY (Red Light) For code – NT. RED light source. For red light sources. 1 3 years K8003DP LED ASSY (Infrared Red Li...
Yes, you can save and copy the FLXA402T configurations by SD card. It realizes easy installation and replacement.
The rotating electrode material changes. -F1 = Gold electrode+celamic beads. -C1 = Gold/Platinum alloy+glass beads. They change the plateau characteristic and reduce combined chlorine sensitivity. On the other hand, available pH range becomes smaller...
Parts No. Name Remarks QTY Recommended Replacement Interval K8005JB Measurement electrode (rotating electrode) Gold electrode for –F1,-F2, and –F3 1 Yearly K8005JC Measurement electro...
Parts No. Name Remarks QTY Recommended Replacement Interval - Primary acetic acid (CH3COOH) grade: over 99.0+% For reagent preparation -   - Sodium acetate (CH3COONa) grade: over 98.0%...
Air purging is required for electrode unit and liquid pump by air pump or compressor air (industrial air). It is required to protect electrode from chlorine gasses which will affect the metal parts.
The FC800D and the RC800D are not suitable for outdoor installation. Strongly recommend installing inside because of pump structure. If you want to install outside, a separate rainproof cover is required and take care install place environment (no co...
Within ordered range, you can set the FLXA402T analog output range seamlessly. Cannot change ordered analyzer measurement range.
Beads become gradually smaller because of friction, and decreases cleaning efficiency. So, we recommend replacing beads once a year.
Rotation electrode will get damaged in case there is no water in the measurement cell. To avoid this situation, the FC800D and the RC800D measurement electrode rotation is automatically stopped. This function makes rotation electrode lifetime longer ...
  -F1 -C1 -F2, -F3 Chlorin conc < 1 mg/L >1 mg/L < = 3 mg/L < = 3 mg/L < = 5 mg/L < = 10 mg/L pH pH: 6 to 8 pH: 6.5 to 7.5 pH: 6.5 to 7.5 pH: 6.5 to 7.5 ...



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