Online turbidity measurement for drinking water

Tethys online turbidity sensor is based on nephelometric method (ISO 7027 – EN 27027). A light beam from a laser diode is sent to the sample through an optical lens. The 90-degree scattered light by suspended particles is collected by a photo detector and converted to an electric signal proportional to the turbidity of the sample. The sensor uses a 650 nm red laser light or on request an 860 nm infrared laser light so that the measuring is not affected by the colour of the sample (ISO7027).

Tethys online turbidity sensor is suitable for measurement of turbidity in drinking water and aquaculture as well as for the outlet of municipal or industrial water treatment plants. It has a minimum detection limit of 0.015 NTU, a light source with a long lifetime and a clear, colour touch screen display with a user-friendly interface which displays all of the readings and graphs of the recorded measurements over the previous 24 hours. A USB port allows software updates and configuration backup/restore

The sensor includes an integrated bubble trap avoid the effect of bubbles on low turbidity measurements. The sensor can be easily opened for calibration on a formazine solution. A valve at the bottom enables the operator to empty the cylinder during calibration operations or for a manual cleaning. The turbidity sensor must be connected to the EL200 controller for display, calibration and measurement transmission though RS232/RS485 under Modbus protocol.

Tethys EL200 controller can also connect turbidity, chlorine and pH sensors to offer a complete solution for drinking water applications.