Online turbidimeters for most on-line turbidity monitoring applications.



  • Meets USEPA method 180.1 and ISO 7027
  • Range of 0 – 1000 NTU
  • Simple, one-piece design
  • Ultrasonic auto cleaning system, EPA accepted
  • Easy to clean and calibrate
  • Convenient reusable primary calibration standards

Online Turbidity Analyzers Product Description

The Global Water TB500 series online turbidimeters are specifically designed for the continuous measurement of turbidity in filtered water, raw water, final wastewater effluent and many industrial applications. Two models of the TB500 online turbidity analyzers are available: The TB502 is a great value, providing reliable and economical online turbidity monitoring with a range of 0 to 1,000 NTUs. The TB504 online turbidimeters feature an EPA accepted ultrasonic cleaning system that keeps the optical chamber clean in raw and finished water applications. The TB504 online turbidimeters also feature a versatile range of 0 to 1,000 NTUs with an accuracy that is the same or better than many smaller range instruments.

Online Turbidity Analyzer Light Source
We offer the TB500 series online tubidimeters in two different versions to meet the needs of different measuring standards.  White light is recommended for use in online turbidimeters reporting results under US EPA (US standard) jurisdiction.  The online turbidity analyzer’s WL (White Light) versions use a new krypton filled white light technology with lamp life expectancy up to 7 years.  The online turbidity analyzer’s IR versions feature a long life infrared light source, which is recommended for use in online turbidimeters reporting results under ISO 7027 (European standard) jurisdiction.  Infrared light is also recommended for waste water final effluent and industrial applications where color is present in the sample stream.

Online Turbidity Analyzer Calibration
Online turbidimeter calibration with primary standards is completed using sealed cuvettes, similar to laboratory procedures.  This dry method of online turbidimeter calibration is fast, clean and reusable.  On-screen menu items guide you through the online turbidity analyzer’s calibration procedure quickly and easily.  The online turbidimeters have reusable primary standards which are contained in sealed glass cuvettes.  Simply place the cuvette into the online turbidity analyzer’s measuring chamber and verify the reading-just like a laboratory turbidity meter.

Online Turbidity Analyzer Advanced Design
The TB500 online turbidimeter’s new optical design allows consistent readings with laboratory and portable turbidimeters.  The online turbidity analyzer’s optical chamber has been designed to eliminate air in the sample while simultaneously creating a vortex cleaning action throughout the chamber.  The online turbidity analyzer’s low-volume sample chamber (30-mL) reduces calibration costs and provides quick response times.  The online turbidity analyzerhas a compact, one-piece, NEMA 4X enclosure is suitable for outdoor installation (within temperature limitations) and allows for simple mounting and minimal use of space.  The TB500 online turbidimeter’s intuitive user interface features security code settings to prevent unauthorized tampering with the programming.  A built-in diagnostic menu on the online turbidimeter assists in troubleshooting.

Online Turbidity Analyzer Outputs
The TB500 online turbidimeter includes an isolated 4-20 mA current output that may be used for chart or data recording, remote monitoring, PLCs or SCADA systems.  Two user settable alarm relays on the online turbidity analyzer may be connected to an autodialer or local alarm to notify you before dangerously high turbidity levels occur.  Also included is an RS485 digital output that may be interfaced with a Modbus system to link multiple units or to integrate the TB500 online turbidimeter into your existing network.

Each TB500 online turbidimeter is shipped fully calibrated and includes desiccant, inline pressure regulator, universal 100-250 volt power supply and an operator’s manual. The TB502 online turbidity analyzer models also include a spare measuring cuvette with light shield.

Online Turbidity Analyzers Product Specification

Range:  0 – 1000 NTU
Measurement Principle:  Nephelometry (90 degrees)
Accuracy:  2% of reading or ± 0.02 below 40 NTU, 5% of reading above 40 NTU
Resolution:  0.0001 Selectable
Response Time:  Adjustable (5 to 500 seconds) (0 – 1000 NTU)
Input Pressure:  1 – 200 psi (built in regulator set at 15 psi)
Standard Outputs:  4-20 mA Galvanic Isolated or RS-485
RS-485 Protocols:  Modbus
Light Source:  White Light – 7 year life, Infrared Light (850nm LED) – 10 year life
User Alarms:  2 High/Low Alarms
Alarm Contacts:  Form C 250 VAC 2A
Display:  Multiline Custom Backlight LCD
Built in Diagnostics:  Yes
Storage Temperature:  -4°F to 140°F (-20°C to 60°C)
Operating Temp:  32°F to 122°F (0°C to 50°C)
Wetted Surfaces:  Nylon, Borosilicate Glass, Silicon, Polypropylene, Stainless Steel
Enclosure:  Designed to meet NEMA 4X, IP66
Outdoor Installation:  32°F to 122°F (0°C to 50°C))
Certifications:  USEPA, ISO 7027, CE Approved, ETL Listed to UL 3111-1 and ETL
     Certified to CSA 22.2 No. 1010-1-92
Dimensions:  14x12x12 inch (35x30x30 cm)
Shipping Weight:  5.5 lbs. (2.5 kg)

Online Turbidity Analyzers Options

TB502-WL Online Turbidity Analyzers (PN# DN0000)
Range: 0 to 1,000 NTU, Light: White, Method: USEPA, Autoclean: No.  NOTE: The TB502-WL is intended for cord connection.  A power cord is not included.

TB502-IR Online Turbidity Analyzers (PN# DN0050)
Range: 0 to 1,000 NTU, Light: Infrared, Method: ISO 7027, Autoclean: No.  NOTE: The TB502-IR is intended for cord connection.  A power cord is not included.

TB504-WL Online Turbidity Analyzers (PN# DN0200)
Range: 0 to 1,000 NTU, Light: White, Method: USEPA, Autoclean: Yes.  NOTE: The TB504-WL is intended for cord connection.  A power cord is not included.

TB504-IR Online Turbidity Analyzers (PN# DN0250)
Range: 0 to 1,000 NTU, Light: Infrared, Method: ISO 7027, Autoclean: Yes.  NOTE: The TB504-IR is intended for cord connection.  A power cord is not included.


Online Turbidity Analyzer Power Cord (PN# 00-302)

TB500-CAL Online Turbidity Analyzer Primary Calibration Kit for TB502 & 504 (PN# DN0300)

TB500-IFR Online Turbidity Analyzer Inline Flow Regulator (PN# DN0390)
The inline flow regulator limits the flow, in high-pressure systems, to safe flow limits of less than 1 liter/minute.  Recommended for pressurized lines.

TB500-ALR Online Turbidity Analyzer Flow Alarm (PN# DN0380)
This option indicates a “Low Flow” condition by switching both relays to the fail state and setting the 4-20 mA signal to 2 mA.  There is also a screen indication of the low flow condition and a modbus register is set.


TB502-CUV Online Turbidity Analyzer Flow Thru Cuvette for TB502 (PN# DN0340)

TB500-UCUV Online Turbidity Analyzer Flow Thru Cuvette for 504 (PN# DN0350)

TB500-DR Online Turbidity Analyzer Desiccant Refill, all models (PN# DN0360)


Turb 430T Portable Turbidity Meter Kit (EPA)
Includes calibration kit (0.02 – 10 – 1000), 2 empty cuvettes, cleaning tissues, batteries (4 x AA), and field case with table insert.


WQ770-B Portable Turbidity Meter
Includes sensor on 25 feet standard cable length.