Online Water Quality Monitor

HORIBA's TW-150 is a process water quality measurement system designed for drinking water and water distribution plants. TW-150 monitors turbidity,color, free residual chlorine, water pressure and pH without any reagent for measurement.
This chemical free method reduces operating costs as it requires minimal maintenance and improves process control.

Division: Water Pollution
Manufacturing Company: HORIBA Advanced Techno Co., Ltd.

Turbidity Method

Measurement method for turbidity is direct NTU value by 90 degree light scattering method and comply with ISO 7027.
Measurement of turbidity and color is performed with a single cell (patent pending).


5 parameters
Turbidity, Color, Free residual chlorine,
Water pressure, pH


7 parameters
Turbidity, Color, Free residual chlorine,
Water pressure, pH, Conductivity,
Water temperature

Touch panel operation

The instrument is operated with a touch screen panel for easy operation and display of measured values.

●Operation panel specifications
320 x 240 dots
Black and white graphic LCD with backlight


User-friendly function

●The adoption of transparent measuring cell enables sample conditions to be easily confirmed.



●The use of thumbscrews makes maintenance easier as special tools are not required.


TW-150 is already monitoring the water supply around the world.

Application Example

Drinking water plant in Japan measures different parameters respective to the process.
The TW-150 conducts final check at the end of the process.

In Malaysia, a software was developed to connect the TW-150 for remote monitoring of the water supply.

More information:
> Case study
> Technical Journal “Readout” (Coming soon)

HORIBA’s drinking water application solutions

Water intake

For periodic check
Multi-Parameter Water Quality Checker U-50
CDOM Aqualog

For continuous monitoring
Organic Pollutant Monitor OPSA-150
On-site Water Quality Meter H-1 Series

Water Treatment plant “process”

For process monitoring
On-site Water Quality Meter H-1 Series

For quality check
CDOM Aqualog

Water Treatment plant “outlet”

For process monitoring
On-site Water Quality Meter H-1 Series
Online Water Quality Monitor TW-150

For quality check
Off-line Water Quality Analyzer LAQUA Series

Pump station / Reservoir

For process monitoring
Online Water Quality Monitor TW-150

Distribution network

For continuous monitoring
Online Water Quality Monitor TW-150

More Information:
> Products for drinking water application

Product name

Water Distribution Monitor



Measurement items(Standard configuration) turbidity, color, free residual chlorine, water pressure, pH
(Optional items) conductivity, water temperature
Measurement Method

See Table 1.

Measurement  Range

See Table  1.


See Table  1.

Display system

LCD display
320 x 240 dot backlit change to five graphic liquid-crystal display (touch panel type)
Up to seven items including five items from standard configuration (turbidity, color, free residual chlorine, water pressure, pH)
and optional items (conductivity, water temperature) can be displayed at the same time.

Calibration method

See Table 1.

Automatic zero calibration

(Turbidity, color, free residual chlorine)
Calibration method: Filtrate sample water
Calibration start: Interior…started by internal timer
       Exterior...started by external contact input
Calibration cycle: 5 hours to 9999 hours (user setting)
Calibration time: Approx. 15 minutes

Automatic cleaning

(Turbidity, color)
Cleaning method: Cell window cleaning using wiper
Cleaning start: Interior...started by internal timer
       Exterior...started by external contact input
Cleaning interval: 5 to 9999 minutes (user setting)
(Free residual chlorine)
Continuous cleaning by using grinding beads

Automatic drainingDraining start: Interior...started by internal timer
Draining interval: 5 to 9999 minutes (user setting)

Sample water condition

Temperature: 0°C to 40°C (do not freeze)
Pressure: 0.1 MPa to 0.75 MPa
Conductivity: 10 mS/m or higher
Analyzing unit input rate (flow rate): 50 mL/mi to 100 mL/min
● In test operation, flush the meter thoroughly before running water.
● Make sure to set up a bypass for piping to the meter.
● If sample water may freeze, take measures to insulate the unit from cold and to retain heat.
● Sample Water measured with this device cannot be distributed.

Ambient temperature,humidity

Ambient temperature: 0°C to 40°C
Ambient humidity: 85% or lower

Analog output

Type: Measurement values: Number of outputs corresponds to number of measurement values (up to seven values including five values of the standard configuration)
Specifications: 4 mA to 20 mA DC, insulated output (non-insulated between items)
Maximum load resistance: 600 Ω
Contact output Types: Power failure, batch alarm, maintenance
Contents: Power failure…occurs when the power is turned off
     Batch alarm…cell temperature adjustment abnormality, temperature compensation abnormality,
           cell wiper abnormality internal communication abnormality, leak, battery abnormality,
           concentration upper limit concentration lower limit,concentration device upper limit,
           concentration device lower limit, light source abnormality zero calibration, span calibration, analyzer abnormality
     Maintenance…when the system enters maintenance or calibration mode
Specifications: No-voltage contact output, a contact interface
     Contact rating: 125 V AC 0.3 A, 30 V DC 1 A (at resistance load)
     Each output is an independent COM interface.

Contact input

Type: Cleaning start, zero calibration start, alarm check setting, abnormal water sampling
Contents: Cleaning start…started by closed contact input
     Zero calibration start…started by closed contact input
     Alarm check setting…started by closed contact input
     Abnormal water sampling... started by closed contact input
Specifications: No-voltage contact input (open collector connection is possible), insulated input
       ON resistance: maximum 100 Ω
       Open voltage: 24 V DC
       Short-circuit current: maximum 13 mA


Interface: RS-232C compatible
Communication speed: 19200 bps


Integrating function for flow rate used in the system (counting type)
Internal leak detecting function

Data memory

Measurement data is stored on system, and can be transferred to a CompactFlash®* (CF Card).
Data saving interval: 1 minute or 1 hour
Data saving frequency: 1 minute: Saves at every 0 second of the minute
          1 hour: Saves at every 0 second of the hour
Data memory time: 1 minute interval…for approx. 10 days
        1 hour interval…for approx. 1 year
The latest data will be stored.
Wiring connectorWiring inlet
Compliant cable: 12.5 mm dia. to 14.5 mm dia.
Power source: 4.5 mm to 6 mm
Pipe connectorSample inlet: Rc1/4
Condensate outlet: Rc1/8
Drain: Rc1/4
Condensate outlet (internal): 6 mm dia. hose nipple
Air inlet: Rc1/8
Condensate outlet (for detection): 6 mm dia. hose nipple (Rc1/8)
Calibration inlet: Rc1/8
InstallationDesigned for indoor installation.
* For outdoor installation, a case is required (option).
Power supply90 V to 264 V AC: 50/60 Hz

Power consumption

100 V to 240 V AC: Maximum 120 VA


Approx. 18 kg 


350 (W) x 160 (D) x 420 (H) (unit: mm)

Paint color

Munsell 5PB 8/1

Installation environment

● Flat and stable location with minimum vibrations or shocks
● No dust, mist or corrosive gas in the air
● Under atmospheric pressure
● No direct sunlight
● Good ventilation
● Altitude 2000 m or lower

* CompactFlash® is a registered trademark or trademark of SanDisc Corporation in the United States and other countries.

[Table 1]
■Standard type

Measurement itemsMeasurement methodMeasurement rangeRepeatabilityCalibration method
Turbidity90 degree light scattering method0 to 2, 0 to 5, 0 to 10 NTU±2.5% of full scaleFormazin standard solution
ColorTransmitted light absorption method0 to 10, 0 to 20 TCU±5.0% of full scaleStandard color solution
Free residual chlorinePolarographic method0 to 5 mg/L±2.5% of full scaleDPD colorimetric method
Water pressureSemiconductor detection method0 to 1 MPa, 0 to 10 Bar±1.0% of full scaleStandard pressure gauge
pHGlass electrode method2 to 12 pH±0.1 pHpH standard solution

■Option (each parameter can be added to the standard type)

Measurement itemsMeasurement methodMeasurement RangeRepeatabilityCalibration method
ConductivityAC 2 pole method0 to 500, 0 to 1000 μS/cm±2.0% of full scaleKCI standard solution
Water temperatureThermistor methodO to 50°C±0.5°CStandard thermometer

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