Turbidity is a general indicator of the optical clarity of water and is defined as the amount of light scattered from particles in solution. In practice, a light beam is directed into a water sample and a photo detector measures the light scattered at 90-degrees to the incident light beam. While other scatter angles are possible, the 90-degree measurement angle has become the standard for turbidity measurement in most water systems. It is used as a relative indicator of the amount of suspended solids in solution, and is measured in virtually all drinking water systems. It is also used in industrial water treatment systems as an indicator of product water quality.

ATI’s Model Q46T Turbidity Water Quality Monitor is designed to meet the needs of both municipal drinking water systems and industrial water treatment for reliable, low-range turbidity measurement.

Using an infrared or energy source in this 90 degree scatter measurement, the system provides high sensitivity measurement with unmatched zero stability. Turbidity measurements down to 0 NTU or as high as 400 NTU can be measured with the same monitor, eliminating the need for separate high and low range instruments.