Under development: Flat SediMeter™

Bridge scour and river turbidity monitoring

This flat SediMeter™ is designed for monitoring the scour around bridge piers. It can also be used for measuring the turbidity profile. Even the water level may be deduced from the data, although there may be more cost-effective ways to monitor the flood stage. The logger also measures the temperature.

With access to water level, bed level, and turbidity, both the discharge and the sediment transport can be estimated, provided that rating curves are available. With access also to the water temperature, the data becomes useful for estimating the trap efficiency in a downstream reservoir.

The patented sensor is the same as in the round SediMeter™: an array of 36 infrared optical backscatter detectors that measure the turbidity every centimeter. A difference is that there is no second plastic layer between the OBS and the water, which means that the turbidity accuracy will be better.

The logger is the same as in the round network version SM2N, supporting RS-485 communication, and built-in memory for 4096 measurements (but without display, USB, or memory card support). It is delivered with a cable that connects to a power source out of the water.

As standard these flat SediMeters are cast in a durable impact-resistant plastic, with totally encapsulated electronics. They should be mounted recessed (whether in wood, concrete, or metal) so that objects in the water do not grab hold of them. The plastic is UV-stabilized, and it can be painted for further protection.

These flat Sedimeters can be mounted in a staggered fashion, to cover whatever vertical interval that is required. There is no limit how many can be deployed, since each one has its own logger and memory. To download data, simply connect a computer at the central. A single USB connection point can serve SediMeters with a total measurement length of over 90 m (300').

Web server: The SediMeter™ software also allows real-time monitoring of such a network of hundreds of SediMeters. Furthermore, it can act as a web server so the monitoring can be supervised from the internet. The total length of the cable may be up to 1200 m. This means that from one point on or near the bridge, one or several bridge piers may be monitored in real time, with data accessible globally within a minute.

Central 2 GB MMC/SD logger: Also under development is a central LogDator™ that can collect data from up to 255 SediMeters and store it in a PC file on an MMC or SD card of up to 2 GB. To retrieve data, simply take out the card. Set up from a built-in user interface with display, or via USB. This logger uses Lindorm's open communication protocol, so it can also be used with other sensors supporting the same protocol (bits 1...6 in the Flags byte will be used to identify the data format in subsequent processing, with x000 000x signifying the SediMeter data format described in the document). Expected release 2009.

It is not designed for use in ice. Ultimately it is up to the user to determine the suitability for a particular application.

Contact us for more information or to request a quote. All specifications are subject to change.

Keywords: SediMeter, scour monitoring, scour meter, turbidity meter, turbidimeter, bridge scour, sediment transport measurement, logger, environmental monitoring, OBS detector.