SediMeter™ SM5

The fifth-generation SediMeter™ (SM5) represents the most significant evolutionary leap in our sensor technology since the original prototype in 1985. For the first time, the instrument can measure sediment levels above the water in broad daylight, opening up a brand-new world of monitoring applications.

Additionally, the standard sensor is longer than ever with 48 OBS detectors, and can be chained to create custom arrays of 96 or 144 detectors.

The Technical Breakthrough: Tidal & Above-Water Monitoring

Each Optical Backscatter Detector (OBS) emits near-infrared (NIR) light and measures the reflection from the surrounding environment. In previous generations (up to SM4), the detectors shared grouped circuitry. While highly effective underwater—where NIR light attenuates rapidly—daylight would overwhelm the sensors when exposed to the air, effectively “blinding” the instrument.

Because many deployments take place in tidal zones where sensors are regularly exposed to the air, we engineered a breakthrough solution for the SM5:

• Independent Measurements: Every single detector on the SM5 is measured independently.
• Ambient Light Compensation: The instrument measures ambient NIR light at every individual level.
• Dual-Mode Detection: When exposed to direct sunlight, the SM5 determines sediment levels by detecting the blockage (absence) of ambient light rather than relying solely on reflected NIR light.

The SM5 also retains the oblique reflection channel first introduced in the SM3, meaning it captures 3 distinct channels at every depth level. The resulting data is rendered as a false-color image, making data interpretation incredibly intuitive.

Key Specs at a Glance

• 48 OBS Detectors: Measuring both reflected and ambient NIR light at every level.
• Upgraded ISO-Style Turbidimeter: For precise water clarity tracking.
• Integrated Thermometer & 3D Accelerometer.

SM5 Configuration Options

SM5A (Standard Model)

The SediMeter™ SM5A is our default, standard configuration. It features the rugged, thick-walled hardware design and dimensions of the legacy SM4P, optimized purely for stationary monitoring (it does not include SediSond™ penetrometer functionality).

Custom & Extended Models

On request, the SM5 electronics can be customized to fit your specific deployment needs:

• SM5: Houses the fifth-generation electronics inside a traditional hardware configuration similar to the original SM4.
• SM5B & SM5C: Extended-length arrays utilizing two or three PCBs to deliver 96 or 144 OBS detectors respectively. (Note: The turbidimeter and accelerometer are not duplicated on extended arrays).

Flyer and Spec Sheets

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