TW-100 Water Distribution Monitor


HORIBA’s TW-100 is a process water quality measurement system designed for drinking water and water distribution plants. The TW-100 monitors turbidity, color, free chlorine and pressure. This chemical free method reduces operating costs as it requires minimal maintenance and improves process control.

TW-100 literature


  • This compact system is equipped with sensors to monitor four water quality parameters. Optional sensors can be added to monitor as many as seven water quality parameters. No reagents are required for the measurement.

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

  • The compact size allows for more installation location options and space for operation.

Manufactured by HORIBA


Product name

Water Distribution Monitor

Model name



Turbidity, color, free chlorine, water pressure (standard); pH, conductivity, water temperature (option)


See chart 1.


See chart 1.


See chart 1.


LCD display: 320 x 240 dot B&W graphic LCD with backlight (touch panel type)
Standard version simultaneously displays four measurement categories (turbidity, color, free chlorine, and water pressure); Optional version simultaneously displays up to seven parameters (the four parameters plus pH, conductivity, and water temperature)

Calibration method

See chart 1.

Automatic zero calibration

(Turbidity, color, free chlorine)
Calibration method: Measurement of filtered sample water
Trigger: Internal control (timer) or external control.
Interval: 1 to 9999 hours (can be set as desired within that range)
Time: 20~99 minutes(can be set as desired within that range)

Automatic cleaning

(Turbidity, color)
Cleaning method: Wiper cleaning
Trigger: Internal control (timer) or external control.
Interval: 5 to 9999 hours (can be set as desired within that range)
(Free chlorine)
Continuous cleaning with beads grinder

Sample water conditions

Temperature: 0 to 40°C (must not freeze)
Pressure: 0.1 to 0.75 Mpa
Flow rate: over 100 mL/min
Flow rate for measurement: 50 to 100 mL/min
* Be sure to flush the sample water before starting the system.
* Be sure to install a bypass for the pipe to which the system is attached.
* If there is any possibility that the sample water could freeze, please protect the system from cold temperature.

Ambient temperature/humidity

Temperature; 0 to 40°C; Humidity: 85% or less

Analog output

Type: Measurement value: Same number as parameters (4 standard, 7 as maximum)
Specifications: DC 4 to 20 mA, insulated output (no insulation between parameters), maximum load resistance 600 Ω

Output signal

Type: Power off, batch alerts, maintenance
Details: Power off: Output when power is off.
Batch alerts: Cell temperature error, compensation temperature error, cell wiper error, internal communication error,water leak, battery error, upper and lower limit of measurement, light source error, zero calibration, span calibration,analyzer error
Maintenance: Output when the system is in maintenance or calibration mode.
Specifications: Non-voltage contact output, a contacts
Contact ratings: AC 125 V, 0.3 A, DC 30 V, 1 A (depends on resistance load), each output COM is independent.

Input signal

Type: Cleaning start, zero calibration start, error check sequence start, error water sampling start
Details: Cleaning start: Cleaning procedure initiated with closed contact input
Zero calibration start: Zero calibration initiated with closed contact input
Error discrimination start: Error discrimination initiated with closed contact input
Error water sample sampling start: Error water sample sampling initiated with closed contact input
Specifications: Non-voltage contact input (open collector contact can be used), insulated input
Resistance when ON: Maximum 100 W; Open voltage: DC 26 V; Short-circuit current: Max. 13 mA


 Interface: RS-232C compliant (*Remote monitoring system is option)


Estimation of sample water volume (counting type), internal water leak detection, error water sampling

Data memory

Measurement values for each parameters are stored in the unit’s data memory. Data can be transferred to a CF card.
Memory interval: 1 minute or 1 hour
Memory schedule: At the top of the hour
Data memory longevity: 1 minute intervals: About 10 days; 1 hour intervals: About 1 year.
* The latest data is written to up date a series of data.

Wiring contact

Wiring ground: For power source: φ4.5 to φ6; For input/output: φ12.5 to φ14

Piping contact

Sample water input: Rc 1/4; Drainage: Rc 1/4; Calibration solution input: Rc 1/8; Error sample sampling aperture: Rc 1/8


Designed for indoor installation. * Housed in a special case (frame) for exterior installation (option).


AC 100 V to AC 230 V, ±10%, 50/60 Hz

Power consumption

AC 100 V to AC 120 V: 120 VA; AC 100 V to AC 230 V: 150 VA


Approx. 15 kg (Measurement unit only)

External dimensions

 350 mm (W) x 160 mm (D) x 420 mm (H) (not including installation fixtures and projecting portions)

Paint color/Material

Munsell 5PB8/1; Unit case is made of SUS.

Installation environment

 Install on a flat surface without vibration shocks. No dust, mist, or corrosive gases in the atmosphere.  Lower air pressure.  No direct sunlight. Ventilated air.  2,000 m or less above sea level.

[Chart 1]
■Standard type





Calibration method


Transmitted light absorption

0 to 2 FTU, 0 to 4 FTU

Full scale ±2.5%

Formazin standard solution or polystyrene latex standard solution


Transmitted light absorption

0 to 10 CU, 0 to 20 CU

Full scale ±5.0%

Standard color solution

Free chlorine


0 to 2 mg/L

Full scale ±2.5%

DPD colorimetry

Water pressure

Diaphragm pressure sensor

0 to 1 MPa

Full scale ±1.0%

Standard pressure gauge

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





Calibration method


Glass electrode

pH 2 to 12

±0.1 pH

pH 7 and pH 9 standard solutions


AC bipole

0 to 50 mS/m

Full scale ±2.0%

KCL standard solution

Water temperature


0 to 50°C


Standard thermometer

Water pressure

Diaphragm pressure sensor

0 to 1 MPa

Full scale ±1.0%

Standard pressure gauge