GF 4170 Turbidity Sensor

Pure precision in turbidity measurement.

Speak to an Expert Download Brochure

Built to last. Designed to perform.

The GF 4170 Turbidimeter redefines what is possible in turbidity measurement with industry-leading accuracy, compact design, and exceptional reliability. It addresses common pain points in turbidity monitoring like leaks, misalignment and frequent maintenance with premium materials and CNC precision manufacturing.  

Pair the sensor with the GF 8640 Turbidity Transmitter that uses advanced touchscreen technology, the transmitter offers intuitive menu navigation and customisable result displays with system and alarm indicators.

The GF 4170 turbidity sensor is best for: municipal drinking water, source water receiving and water intake, seawater/brackish water/desalination, reverse osmosis and filtration, industrial wastewater and reclamation, cooling tower and process water.

Crafted for Flexibility and Longevity

Designed for use by OEMs and plant operators alike, the GF 4170 Turbidity Sensor performs flawlessly whether installed in tight pipework or exposed to harsh process environments. With international certifications, this sensor is ideal for compliance critical water systems. 

Additionally, its wide measurement range ensures accurate surface and intake water surveillance measurements, even as water color varies. 

10x more accurate

Achieves an impressive accuracy of +/-0.1% to +/-0.2% across one of the largest measurement ranges available on the market.

7-point calibration

7-point factory calibration provides superior accuracy across the entire turbidity range compared to the typical 1-2 point calibrations used by competitors.

Built for global compliance

GF’s turbidity sensor complies with international standards and supports global regulatory approval, with documentation ready for audits. It meets ISO 7027 turbidity measurement benchmarks which are widely accepted in both industrial and environmental segments.

Extend sensor lifetime up-to 5X

GF’s turbidity sensor is designed without O-rings, utilises CNC precision and sapphire windows-to-metal sealing to eliminate leak risks and extend its lifetime by 3-5 times compared to conventional designs.

Experience Pure Precision

Industries served

Drinking Water

Only the best components are good enough when dealing with the world's most valuable resource. Our highest-quality piping systems support the safe handling of drinking water, while our Process Automation solutions make decentralised treatment and production easy.

Wastewater Treatment

Reusing the world's most valuable resource. Reliable and sustainable wastewater treatment with interoperable thermoplastic piping systems. 

Industrial Water Treatment

Plastic piping systems improve water treatment with corrosion resistance, easy installation, and energy savings, offering durability and efficiency in modern industrial settings. Enhance efficiency, save costs, and meet regulations using plastic piping in industrial water treatment.

Dubai. In the summer of 2016. Modern desalination plant on the shores of the Arabian Gulf.

Desalination

Corrosion-resistant and robust thermoplastic piping systems are the optimal solution for future-proof, reliable desalination with increased system longevity.

Portfolio

FAQs

What is turbidity?

Turbidity measures how clear or cloudy a liquid is, based on the light-scattering effect of suspended particles. It is not the same as color.

What is ISO 7027 and why is it important for turbidity measurement?

ISO 7027 is an international standard that defines the method for measuring turbidity using near-infrared light at 860 nm and a 90° nephelometric detection angle. It ensures consistent, color-independent turbidity readings and is widely accepted in drinking water, wastewater, and industrial process applications. Compliance with ISO 7027 guarantees traceability, comparability, and regulatory acceptance across many global regions.

Is the sensor compatible with both clean and dirty water applications?

Yes. The wide measurement range (0.001-4000 NTU), self-cleaning slanted head, and rugged design make the sensor suitable for both low-turbidity applications like drinking water and high-turbidity environments such as industrial wastewater or mining.

What is the measurement range and accuracy of the Type 4170 sensor?

0.001 to 4000 NTU/FNU, with accuracy of ±0.2% MV (0-0.5 NTU) and ±0.1% MV in other ranges.

Can this turbidity sensor also measure Total Suspended Solids (TSS)?

Yes. TSS can be estimated by correlating turbidity (FNU) to TSS (mg/L) through lab analysis of grab samples. The conversion factor can be entered into the transmitter for real-time TSS display. TSS is a lab-based measurement, and many TSS sensors on the market use similar optical principles typically calibrated with diatomaceous earth or similar standards. In most cases, turbidity and TSS estimation can be performed using the same sensor, depending on the application range.

What needs to be considered when choosing a turbidity sensor?

Key factors include required measurement range, sensor accuracy at low and high turbidity, sensitivity to color, maintenance needs, installation type (inline, open channel, bypass), and compliance with standards like ISO 7027. The GF Type 4170 sensor is designed to address these needs with a wide dynamic range (0.001 - 4000 FNU), high precision, low maintenance, flexible installation options, and ISO-compliant accuracy, making it suitable for most industrial and water treatment applications.

How is maintenance handled?

The sensor is nearly maintenance-free. It has no O-rings in the optical path (sapphire to sensor body) or moving parts. The slanted head design promotes passive self-cleaning, reducing fouling. Only the desiccant may need replacement, typically after about one year.

In which applications Type 4170 are typically used?

Applications include - drinking water (treatment & distribution); RO/UF protection; surface/river intake; industrial wastewater; cooling towers; mining and tailings monitoring

Can it be used in seawater or brine?

Yes. The Type 4170 turbidity sensor is built with materials and optics suitable for brackish water and desalination pretreatment.

Is the GF Type 4170 turbidity sensor compatible with 9900 or 9950 transmitters?

No. The Type 4170 sensor is only compatible with the GF Type 8640 transmitter. 


The sensor offers 4-20 mA, Modbus RTU, and two digital outputs (0 or 1 digital output). The transmitter includes 4-20 mA as standard and can be field-upgraded with Modbus RTU, Profibus DP, or Profinet modules for flexible system integration.

George Fischer Sales Ltd

Paradise Way

CV2 2ST Coventry

UK