SDM: Slurry Density Meter

After years to be successful with model 9690, Rhosonics introduces the latest generation density meter, the SDM series. This instrument is suitable for density measurement in all kinds of slurries. The product differentiates itself with its sustainable technology and its specific design for dredging and mineral processing applications.

Dredging and mining companies are increasingly looking for non-nuclear measurement equipment. A growing demand is seen for non-nuclear alternatives, because of stricter government regulations, safety related costs and the need to reduce nuclear waste. The SDM makes use of non-intrusive ultrasonic sensors to measure the density of mineral slurries. Like nuclear density gauges, the SDM is able to measure under high density levels and at very large pipes.

By measuring the acoustic impedance of a slurry, the SDM calculates the density of the slurry in-line during the process. The sensor is made of stainless steel and ceramic material. Because of the new sensor material, the sensor has lots of better properties. By making use of ceramics material, the ultrasonic signal is more brightful and powerful than before. Also, the sensor is at least as wear resistant as its predecessor, model 9690. By means of wafer cells, spool pieces or even a weld-on piece, installation is possible at very large pipe sizes like 32” and even higher.

Get in touch with Rhosonics for further information about the Slurry Density Meter (SDM).

Download the SDM Brochure: English - Portuguese - Spanish

Download the SDM Case Study: Dredging - Mining

Features and benefits

  • Non-Nuclear technology
  • Durable probe system
  • Lowest possible maintenance needs
  • High accuracy and reproducibility
  • Suitable for all types of slurries
  • Compact integrated system
  • Process connection via HART and 4-20mA
  • Continuous data & system logging
  • New temperature technology

Performance specifications


Ultrasonic Spectral Power /

Acoustic impedance

Density Range:

700 … 3.000 g/l


0.2 g/l


S.G., Density g/l


Up to 0.005 S.G … +/- 0.5%

Decay time:

1 to 99 s (adjustable)


Monochrome display with RGB backlight, visible through glass cover.


Push-buttons, HART, Computer

General specifications

Process conditions


1 … 16 bar


0 °C … 110 °C (32 °F … 230 °F)

Wetted materials:

Ceramics and Duplex Stainless steel 1.4462

Electrical specifications

Power supply:

18 … 32 VDC, 8 Watt

Optional: Power supply/converter for 90 … 240 VAC


4 … 20 mA / HART


2-way through HART protocol

Data logging & fault reporting:

Internal memory,

via USB memory stick

Cable entries:

3X M16X1.5, cable OD Ø 3-10 mm

Ambient conditions

Ambient temperature:

-20 °C … +65 °C (-4 °F … 149 °F)


< 95% at 40 °C (noncondensing)




Resistant to moderate / high vibration of pumps

Dimensions and weights


Approx. 6.4 – 6.8 kg

Housing materials:

Coated stainless steel

Housing dimensions:

218–402* (L) x 208 (W) x 170 mm (H)

* Various depths, depending on probe type

Process connection:

Spool (sensor depth: 16 mm)

Weldolet (sensor depth: 34 or 52mm)

Wafer (sensor depth: 146 or 200 mm)


DIN/ANSI/JIS (others on request)

Nominal pipe size:

Up to 60”

Get in touch with Rhosonics for further information about the SDM slurry density meter.

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