The U31 is designed for underwater ACFM inspection by either diver or ROV.

However, the same instrument can also support underwater lift-off measurement probes. including the marine fouling thickness gauge and probes to measure coating thickness or ovality of pipelines.

Although the U31D is capable of inspection in water depths up to 350m (and the U31R even deeper). For shallow water (less than 50m), it is possible to use the AMIGO topside instrument with special underwater probes.

	Underwater Lift-Off Measurement For further details, see Marine Fouling Thickness Gauge or ovality of pipelines.
	AMIGO Instrument for Underwater Use Suitable for shallow water inspection when used with underwater probes. For further details, see AMIGO.