Industrial Applications Include:

  • Potable water
  • Wastewater
  • Dairy
  • Mining
  • Chemical
  • Food and beverage
  • Breweries
  • Pulp and paper
  • Petrochemical
  • Forestry
  • Environmental

Turbidity Sensor Model 851

The Confab Model 851 Turbidity Sensor is a rugged DC-powered insertion-type probe that measures turbidity as a standalone unit. Since the sensor can be inserted into any size pipe, costly bypass systems are not required. The design eliminates the effects of fluid color. In-situ measurements provide instantaneous, accurate readings and the sensor has an isolated linear 4-20mA output for connection to control/monitoring systems. Calibrated range switches allow for the selection of four ranges from 0-2 NTU to 0-2000 NTU.

Instantaneous Response
Because the sensor optics are in the process stream, the Model 851 turbidity sensor does not require bypass systems. Our in-stream measurement eliminates slow response times inherent with turbidimeters requiring bypass plumbing. The Model 851 is extremely effective where filter monitoring is crucial, and efficiency or breakthrough must be detected quickly.

Wide Dynamic Range
Our turbidity sensor has four ranges from 0-2 NTU to 0-2000 NTU. The low-level range (0-2 NTU) has a resolution of 0.001 NTU and is useful in processes where very low turbidity measurement is required. The higher ranges can be used on raw water supplies and other processes where turbidity is monitored before filtering.

Handles Harsh Process Conditions
The optical design of the sensor minimizes the effects of fluid color, flow, chemicals, temperature & pressure. Our instrument operates under a wide range of temperature and pressure conditions. Robust wetted parts are 316 stainless steel and glass for high resistance to process chemicals.

Data Communication
Our turbidity sensor comes standard with an isolated 4-20mA output for connection to third party control/monitoring systems. Other outputs are available.

Minimal Maintenance
The Model 851 uses a light source with a 13-year life expectancy which provides long-term stability and very low maintenance. Although our turbidity monitor is easily calibrated by the end user, calibration drift is minimal. Because sensor removal is simple, the optics can readily be cleaned as necessary.

Limited one-year warranty against defects in material and workmanship.


All prices in US Dollars and do not include applicable taxes, shipping, duties and customs fees. Please contact us for quantity discount and reseller information.

Calibration Standard

A complete description of the calibration process for the Model 850 Turbidimeter is available in our Installation Manual. Calibration standard solution is available directly from GFS Chemicals using the links below. We recommend you purchase a minimum volume of 500ml.

0 NTU Standard

10 NTU Standard

100 NTU Standard

1000 NTU Standard


Ready to Order?
Type Insertion Probe
Range 0-2NTU, 0-20NTU, 0-200NTU, 0-2000NTU Switch Selectable
Power 24 VDC @ 100mA standard. Optional 12 VDC @ 200mA
Output 4-20 mA into 600 ohms max. isolated, other outputs available

Pipe Size

Pipes greater than 2 inches
Wetted Parts 316 stainless steel, sapphire
Process Temperature -10C to 110C
Pressure 0 to 150 psig
Mounting 1" NPT male
Resolution 0.001NTU
Repeatability 0.001NTU
Accuracy 1% of Scale
Ambient Temperature 0C to 50C
Enclosure Dust Proof, Waterproof
Cable Length 25 feet standard, optional lengths available up to 1000 feet
Shipping Weight 6-10 pounds depending on cable length
Tube Diameter 7/8"
Tube Length 12"
Junction Box 2.5"x3"x6"
Overall Length 21"
Typical Sensor Mounting