Turbidity Measurement
The darker the better: Multipath 90° BLAC® technology
Measure your water samples with unsurpassed accuracy - whether they have low or high turbidity values. What used to be a real problem has been solved by our experts: Multipath 90° BLAC® covers a unique turbidity range. 
What are Turbidimeters used for?
A turbidity value is a way of quantifying the cloudiness, or haziness of a sample.  It is calculated, using an instrument called a turbidimeter, by measuring the amount of light scattered or blocked by suspended particles in a water sample.  We often think of turbidity in terms of things like microorganisms, silt or other materials - but turbidity can literally anything present in the sample that causes the light beam to scatter.  Turbidimeters are available as portable, benchtop or online instruments.
Compliance and light sources
ISO and the US EPA are the two main organisations that govern the design critera of a turbidimeter and set specifications or even regulations for turbidity measurement. Compliance to one of these standards is regionally based.
Turbidity Measurement
In pool water, turbidity is an indication for the effectiveness of the filter system and cleaning agents. In drinking water it indicates the possible bacterial growth. In sewage treatment plants the turbidity is an indicator of quality in the cleaning procedures. In industries, turbidity is a quality criterion for products. The cause of turbidity is usually tiny small particles or droplets that do not dissolve in the surrounding liquids.
Turbidity Measurement in Pool Water
In pool water, turbidity is an indication for the effectiveness of the filter system and cleaning agents. In drinking water it indicates the possible bacterial growth.
Nephelometrie
If a light beam hits a liquid that is clouded by small, undissolved particles, part of the light is scattered to the side of the incoming beam. The phenomenon is called the Tyndall effect.The scattering depends on the way the light hits the particle, but also on its shape.
Understanding Interferences
A detector placed at 90° detects the scattering caused by the particles. The greater the scatter, the higher the turbidity value. Depending on the application or industry in which the device is used, additional scattered light detectors can be used at other angles.
Drinking water treatment : PTV 1000 field test report
When disinfecting surface water or water that is affected by surface water during treatment in waterworks, checking the turbidity is of crucial importance for choosing the optimum disinfection effiency. With the PTV 1000 series instruments, Lovibond® has developed on-line turbidimeters that successfully handles the usual problems in this area in practice. This has now been confirmed by a long-term test in the drinking water treatment of a Dutch waterworks.
Applications of continuous turbidity measurement in drinking water processing
The monitoring of the indicator parameter turbidity with a limit value of 1 NTU / FNU is one of the legal obligations of the operator of a waterworks and is considered to be complied with if this value is maintained at the waterworks exit. In-house laboratories usually take on these tasks and report the results to the responsible supervisory authority according to a defined sampling plan.
The Science Behind Your Turbidity Measurements
On the surface, turbidity analysis is a simple measurement. But there are all sorts of factors that can have an effect on the accuracy of readings or the dependability of an instrument.  At Lovibond®, we obsess about turbidity measurement so you don't have to. Our team of globally recognized turbidity experts work to anticipate and solve operators' struggles with turbidity measurement. 
The Important Role of Process Turbidimeters in Water Quality Measurement
Turbidity is described in the Standard Methods for the Examination of Water and Wastewater Method 2130B (EPA Method 180.1) for turbidity measurement as, “an expression of the optical property that causes light to be scattered and absorbed rather than transmitted in straight lines through the sample” (Standard Methods, 1995). More simply, a turbidity value is a way of quantifying the cloudiness, or haziness of a sample and it has long been used by people as an direct indicator of overall water quality.