ACFM systems have been used since 1991 for underwater inspection of offshore platforms, subsea structures and pipelines. The U31 Underwater ACFM Crack Microgauge is the third generation instrument and represents a significant advance in ACFM subsea inspection technology from the previous U21.

The U31 instrument has all the advantages of ACFM inspection available on other TSC instruments in a small and light package designed specifically for diver and ROV deployment.

Diver Deployment

The diver deployed U31D is a top-side powered instrument, linked to a top-side PC and power supply via a single sub-sea cable. It is equipped with top cage to allow the diver to easily manoeuvre the instrument and provide an anchor point for a retaining rope or cable. The small size, light weight and ease of manoeuvrability translate into great versatility sub-sea and allows the instrument to be deployed from dive stations without the need for cranes or tuggers. The probes and communications cable use wet mateable connectors which allow them to be changed in a wet environment but not underwater.

ROV Deployment

Interface with ROV systems is straightforward. The probe is mounted onto an ROV manipulator and is deployed onto the inspection site. An umbilical is routed from the probe along the manipulator arm to the U31R subsea unit. The subsea unit takes it's power from the ROV and communications to and from the topside control box are via the ROV umbilical. The control box is then connected to a top-side PC running TSC's proprietary software.