The SediMeter measures a vertical turbidity profile and interpolates the bottom level with high resolution
The "color SediMeter", new for 2017, is the instrument of choice for measuring sedimentation, erosion, siltation, scour, and resuspension. It measures a 35 cm long vertical profile of turbidity at 71 levels using 36 near infrared optical backscatter detectors, 1 cm apart. The instrument reports the turbidity profile in color, and the interpolated bottom elevation. The color plot with 5 mm vertical resolution is the result of measuring both straight and oblique backscatter. Brown to beige tones denote buried detectors, while those exposed to air become blue.
The SediMeter can be used to get quantitative data on the dynamics of the sea floor with high temporal resolution, and it is ideal for monitoring sediment spill from dredging in real-time. It can also be used to monitor what is happening below the bottom, inside the sediment pack, i.e. anoxia and methane bubble formation. The 10 µm resolution allows for the detection of change on a very minute scale, such as caused by bedload sediment tranport. Sedimentation of as little as 100 g/m2 can be detected reliably.
SediMeter™ model SM3A mounted in Biscayne Bay.
There is also a dedicated OBS turbidity sensor mounted higher up. The calculated level, along with this turbidity, can be measured as "burst samples", up to 20 times for each measurement, at an interval of between 1 and 16 seconds. Software is included.
Model SM3B has a built-in mechanical cleaner (left). Model SM3A has a diameter of only 15 mm (right). A new model SM3C looks like SM3A but features a vibrator for sensor cleaning without external moving parts. The SediMeter offers several deployment options. The instrument can be used both as a stand-alone logger and connected to a cable.
In 2017 we released firmware rev. 2.0 for SM3, which drastically improved the usefulness of the third generation of SediMeters by measuring turbidity every 5 mm, in two different ways, and presenting the data as a color plot. We alse introduced SM3C, a model with a vibrator instead of a mechanical cleaner.
SediLink™ radio modem
A SediLink™ radio modem (pdf) can be used to replace cable. It has a recheargeable battery, and a built in solar panel to charge itself and the connected SediMeters. It also has white blinking lights to alert seafarers about the buoy. The SediLink™ has a socket for an X-Bee radio, allowing a choice of inexpensive radio depending on the need for range, and the local regulations. It mounts on top of a tube with the cable through the tube and down to the instruments on the bottom. It can be used anywhere that X-Bee radios are sold: North and South America, Europe, Australia, and so on. Contact us for a quote.
The SediLink™ radio modem mounted on a buoy.