Dredgers long used nuclear (Cs-137) density gauges because gamma reads density straight through the pipe wall, non-contacting. But on a vessel that convenience comes with real cost.
The shipboard burden of a nuclear gauge
- Radiation licensing that follows the vessel across borders;
- Port-state inspection delays and paperwork on mobilisation;
- A radiation-safety officer, leak tests and controlled disposal at end of life.
The non-nuclear alternative
A PS7000 ultrasonic acoustic-impedance meter reads discharge-line density to ±0.005 g/cm³ with no radioactive source — none of the above burden. A flush sapphire window resists abrasion; Chirp wideband processing rejects the entrained air common in dredge lines. For no-hot-work retrofits, the clamp-on PS7010 mounts outside the pipe. Nuclear keeps one genuine edge: it still works through very thick or heavily lined pipe where nothing can contact the slurry.
Add production, not just density
Pair the meter with flow and the Dredge Production Monitor to get dry-solids t/h. Compare in detail: PS7000 vs Cs-137 · PS7000 vs Rhosonics SDM ECO. See the dredging page.