Slurry density is one of the hardest density-meter scenarios — high solids, abrasion, temperature variation, scaling. The PS7010 (ultrasonic attenuation) and PS7400 (tuning fork) are the two Pisonics products most often compared head-to-head. Here's how they actually differ in the field.
Slurry density: ultrasonic vs tuning fork — how to choose?
Engineering comparison between clamp-on acoustic-attenuation ultrasonic and immersed tuning fork — covers abrasion handling, scaling tolerance, installation intrusiveness.
Steps
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Working principle
PS7010 measures acoustic attenuation as ultrasound passes through the slurry — sensor mounts clamp-on outside the pipe. PS7400 measures the vibration frequency change of a fork immersed in the medium.
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Intrusiveness
PS7010 is fully clamp-on, no medium contact, no wetted parts. PS7400 is insertion-mount with the fork in the slurry — needs a wear-resistant tip for abrasive media. If process rules forbid tapping (some HPAL circuits), only PS7010 works.
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Scaling resistance
PS7400 has a large vibration amplitude that shakes off scale particles — excellent scaling tolerance. PS7010 doesn't touch the medium so scaling on the fork doesn't apply, but pipe-wall thickness must stay stable (wall scaling itself affects attenuation readings).
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Accuracy comparison
Both are around ±0.005 g/cm³ under normal conditions — close enough. PS7010 is more sensitive to entrained gas (acoustic scattering). PS7400 holds up better at extreme solids (> 60%).
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Application summary
Choose PS7010: no tapping allowed / stable pipe wall / low gas / no near-term piping changes.
Choose PS7400: typical slurry (20–60% solids) / insertion mount OK / scaling environment.
Unsure? Budget for both and let a Pisonics engineer visit the site before deciding.