In 2014 the NSRP Surface Preparation & Coatings Panel obtained approval from the Executive Control Board for funding of a project that would evaluate the latest in digital coating inspection instruments and their potential for cost savings in the inspection of Navy vessels.

The purpose of the study was to compare and contrast the 009-32 legacy method of coating inspection with the latest digital inspection tools.

TEST METHOD

The project consisted of a side-by-side comparison of three test methods used to evaluate Dry Film Thickness in ballast tanks and other painted surfaces:

• Method 1: Current NSI (Navy Standard Item) 009-32 Practice - analogue or digital measurements taken with Type 2 Coating Thickness gauge. Reporting was completed via legacy (current shipyard) method
• Method 2: Scanning  - new DFT scanning technology used to take measurements. Reporting was completed using digital data management system
• Method 3: Factory Calibration - new factory calibrated and pre-programmed DFT device designed to take a single measurement in lieu of the three spot-measurement requirement of SSPC PA2. Reporting was completed via legacy (current shipyard) method

Two new methods – Method 2 and Method 3 were compared with the current 009-32 Method for instrument accuracy, data retention, speed of inspection and speed of data capture.

RESULTS

Data Integrity

• There is no significant difference in data obtained by the currently specified inspection method and the latest digital inspection tools
• Each instrument and method has a comparable standard deviation
• Data generated from testing NAVSEA approved panels in the laboratory environment shows no loss of accuracy or repeatability when using the latest digital inspection tools
• There is no degradation of instrument performance when taken from a laboratory environment into the field

Inspection Time

• Digital instruments were two to three times faster than the current NAVSEA specified data collection method
• Scanning technology demonstrated the most significant time savings
• Factory calibrated DFT instrument completed identical inspections in approximately one half the time using the current paper based data retention method.

Data Output and Report Generation

Time savings for report generation between manual report generation and digital methods were so significant that the benefits of digital reporting are unquantifiable.

For a copy of the full report, methods and analysis please click here.