In September 2016, the Dutch civil engineering contractor “Martens en Van Oord” (MvO) started a project for the expansion of the Beatrix locks in the Lekkanaal at Nieuwegein in The Netherlands. The Lekkanaal is a busy canal with many ships passing the locks. To prevent a bottle neck with the increasing traffic, it was decided to construct a third lock, in parallel to the existing two locks. Also the canal itself will be widened. (Link to the project on the MvO site)

The project obviously involves a lot of dredging and earthmoving. Inevitably, this will soil to become suspended in the water of the canal. To control the amount of suspension, MvO decided to continuously monitor the turbidity at a fixed location, and to conduct spot measurements using a hand held device.

MvO asked Observator Instruments to deliver a complete autonomous turbidity monitoring system, consisting of a turbidity sensor (NEP-5000), a data logger with integrated GPRS modem (OMC-045-III) and solar power. The dashboard software (OMC-Data-Online) is hosted by Observator. This allows MvO to simply login from any computer or mobile device to inspect the measurements. Alarm messages are send when appropriate to the mobile phones of the responsible people.

In addition to the fixed station, MvO uses the NEP-5000-LINK turbidity handheld to conduct spot measurements. This handheld uses a turbidity sensor based on the NEP-5000 technology in a smaller housing. A cable connects the sensor to a Bluetooth module that communicates to a mobile phone or tabled. An Android App allows the operator to immediately see the real-time turbidity values, as well as to make recordings. With the touch of a button, the data are send to the server for handling by the OMC-Data-Online software.

The turbidity monitoring station with NEP-5000 sensor, solar power and data transmission by GPRS.

Spot monitoring with the turbidity handheld and the NEP-LINK App on a mobile phone.