Long Range Ultrasonic System(LORUS) Technique
LORUS applies high sensitivity angle beam transducers in combination with an ultrasonic data recording system. The ultrasonic wave travels over multiple skips into the hard-to-access region. The presence of corrosion is established in the pulse-echo reflection mode. Reflection signals can be recorded together with 3-axis position encoder information. Coherent projection maps are calculated, showing directly location and extent of corrosion in one-to-one images.
Tank Floor Inspection from Annular Plate using LORUS
General inspection capabilities
LORUS has been developed for fast screening of hard-to-access locations, such as detection of corrosion in a storage tank’s annular plate from the outside of the tank.
From a single access point, a large region may be inspected without direct access to the surface. Corrosion detection is achieved over a considerable distance (typically up to 1 meter). Compact manual scanners are applied in case of limited access and mechanized scanners are applied where possible for high inspection speed.
– range up to 1 metre
– suitable for any tank diameter
– suitable for annular plates from 6 to 25mm thick
– ability to detect severe (pitting) corrosion
– ability to detect local gradual corrosion
– corrosion mapping and area estimation
– suitable for corrosion growth monitoring
– reflectivity of corroded areas may be used to estimate severity
Inspection limitations
complete coverage of tank floor is not possible
– no discrimination between top and reverse side corrosion
– the scanning surface must be free of impurities, welding slag, surface corrosion and coatings, unless the coating is well bonded.
– poor annular ring condition may affect the inspection range.
Access requirements
Minimal. Deployed remotely from corrosion site.
