Ultrasonic thickness gauging (UTG) measures how much metal is actually left in a structure — without cutting it open, draining it, or taking it out of service. A probe sends a sound pulse through the material and times its return, giving a thickness reading accurate to a fraction of a millimetre. Repeated over time, those readings show exactly how fast corrosion is eating into your asset, and how long it can safely stay in service.
Class-Approved Thickness Measurement
Thickness measurement on hull structures is not work that any contractor may perform. Classification societies require it to be carried out by an approved service supplier, working to a documented procedure with calibrated equipment and qualified operators.
PT Hi Tech Marine Inspection is approved by ABS, BKI, BV, RINA, ClassNK, KR, DNV, IRS and LR. Our reports are prepared in the format class surveyors expect, so your survey is not delayed by paperwork that has to be redone.
What We Measure
- Ship hull plating, frames, and internal structural members
- Storage tanks — shell courses, bottom plates, and roofs
- Pressure vessels and boiler components
- Process and transmission piping, including elbows and bends
- Structural steelwork and offshore members
- Corrosion mapping across defined grids for trend analysis
Where UTG Is Used
- Class and intermediate surveys — thickness measurement reports for hull renewal assessment
- Corrosion monitoring programmes — repeat readings at fixed locations to track wear rate
- Fitness-for-service assessment — establishing remaining wall thickness against minimum required
- Pre-purchase and condition surveys — verifying the real condition of an asset before a transaction
- Post-repair verification — confirming plate renewal and weld build-up meet specification
How We Work
- Scope agreement — we agree the measurement locations, grid density, and reporting format with you and, where relevant, with the attending class surveyor.
- Surface preparation — coatings and scale are removed where required so the probe reads the metal, not the paint.
- Calibration — equipment is calibrated on reference blocks of known thickness before and during the work, with velocity set for the material being tested.
- Measurement — readings are taken at the agreed points, with repeat readings where results are inconsistent.
- Reporting — results are tabulated against original and minimum thickness, with diminution percentages and clearly marked locations.
Rope Access Where Scaffolding Does Not Reach
Many of the points that most need measuring are the hardest to reach — upper shell courses, internal tank structures, hull sides afloat, and offshore members. Our IRATA-certified technicians hold both rope access and NDT qualifications, so the same person who reaches the location also takes the reading. That removes the cost and programme time of erecting scaffolding purely to obtain a set of thickness readings.
Why Work With Us
- Approved service supplier for nine major classification societies
- Personnel qualified and certified in accordance with ASNT SNT-TC-1A and ISO 9712
- IRATA-certified rope access capability combined with NDT qualification
- Calibrated, traceable equipment
- Reports written to be used — clear location references, tabulated results, and findings stated as found
- Based in Batam, close to the shipyards and fabrication facilities we serve
Request a Quote
Tell us the asset, the scope, and your survey window, and we will come back with a clear quotation and a realistic schedule.
Phone / WhatsApp: +62 813 7202 1412
Email: info@htmarineinspection.com
Office hours: Monday – Friday 08.00 – 17.00, Saturday 08.00 – 14.00