Clamp-On Ultrasonic vs Inline Meters: Which to Choose?

When clamp-on wins

• Cannot cut the pipe or stop the flow (live retrofit)
• Large pipes where an inline meter would be expensive
• Projects where the budget favors the lowest installed cost

Expect ±1–2% reading accuracy, which is enough for survey and balance work.

When an inline meter wins

• Trade and custody measurements needing ±0.5% or better
• Small bores (under DN25) where clamping gets unreliable
• Liquids with heavy aeration or gas — clamp-ons struggle with gas bubbles

What both need from the pipe

• A full, free-flowing line with no air pockets
• Straight runs: 10D upstream and 5D downstream for reliable results
• Clean outside surface for transducer coupling

Our recommendation

Use clamp-on to verify an existing line cheaply in a week, and inline where accuracy and repeatability become contractual. We can loan a clamp-on kit for a site survey with our engineers guiding the measurements remotely.