Coating Thickness Gauge for Painting Contractors DFT Inspection Before Project Handover Malaysia
For industrial painting contractors, completing the painting work is only part of the job. Before project handover, the contractor may also need to demonstrate that the finished coating complies with the required coating specification. One important measurement is DFT Dry Film Thickness. A portable coating thickness gauge allows painting contractors to check suitable coatings on metal substrates quickly and non-destructively before the client, consultant or inspector performs the final inspection. For general industrial coating applications, the TASI TA522A Coating Thickness Gauge provides Fe/NFe measurement, a 02000 μm range, automatic substrate recognition and manual measurement mode selection. Why Should Painting Contractors Measure DFT? Imagine completing a large steel painting project and waiting until the final handover inspection to discover that coating thickness is outside the required specification. At that point, corrective work can become expensive. Possible consequences include: Rework Additional coating application Project delays Additional labour Additional material consumption Reinspection Handover delays Customer disputes Performing internal DFT checks before formal inspection gives the contractor an opportunity to identify potential issues earlier. The coating thickness gauge therefore becomes more than a measurement tool. It can become part of the contractor's quality-control process. What Is DFT? DFT stands for: Dry Film Thickness It describes the thickness of a coating after it has dried or cured. Depending on the industry, the instrument used to measure DFT may also be called: DFT gauge Dry film thickness gauge Coating thickness gauge Paint thickness gauge Coating thickness meter Paint thickness meter For industrial painting contractors, DFT gauge and coating thickness gauge are particularly common terms. Where Do Painting Contractors Use DFT Gauges? Potential applications include: Structural steel Factory buildings Warehouses Machinery Steel tanks Industrial piping Equipment frames Platforms Handrails Steel fabrication Protective coating systems Maintenance repainting The exact coating specification and inspection requirement will depend on the project. Measuring Paint on Steel Steel is one of the most common substrates encountered by industrial painting contractors. For suitable non-magnetic coatings over ferrous steel, the magnetic induction principle is commonly used. A simplified coating structure is: Steel → Protective Coating or, for a multi-coat system: Steel → Primer → Intermediate Coat → Topcoat A suitable DFT gauge can measure the finished coating system over the steel substrate according to its measurement principle. The reading can then be compared with the project's specified requirements. TASI TA522A for Contractor DFT Inspection The TASI TA522A provides: Measurement range: 02000 μm Stated accuracy: ±(3% + 1 μm) Fe magnetic induction measurement NFe eddy current measurement Automatic substrate recognition Manual measurement mode selection Fe+Zn measurement capability Zero calibration μm / mm / mil selectable units 2 readings per second 180° screen rotation For contractors performing repeated measurements on steel, the ability to manually select the appropriate measurement mode can be useful. Why Contractors Should Check Before the Inspector Arrives A practical QC process can be: Painting Completed → Contractor Internal DFT Check → Corrective Action if Required → Final Inspection → Handover This is preferable to: Painting Completed → Final Inspector Finds Problem → Rework → Reinspection → Delay Internal measurement does not replace formal inspection when formal inspection is required. Instead, it helps the contractor prepare for that inspection. When Should DFT Be Measured? The appropriate inspection timing depends on the coating system and applicable procedure. DFT refers to the coating after drying or curing, so measurements should be performed according to the coating manufacturer's requirements, project specification and applicable inspection procedure. Do not assume that a coating that feels dry is automatically ready for final DFT acceptance measurement. How to Perform a Basic DFT Check 1. Review the Project Requirement Before taking measurements, know what you are checking against. The project documents may specify: Coating system Required DFT Minimum or maximum thickness Number of readings Measurement locations Applicable standard Acceptance criteria Without an acceptance requirement, a thickness number by itself does not tell you whether the coating passes. 2. Confirm the Substrate Determine whether the substrate is steel, aluminium, galvanized steel or another material. This affects the appropriate measurement principle. 3. Check the Gauge Follow the instrument manufacturer's instructions regarding zero calibration and preparation. Professional project work may also require specific calibration or verification procedures. 4. Select Measurement Locations Do not simply measure the easiest point. Follow the project inspection plan or applicable procedure. 5. Take Multiple Readings Coating thickness can vary across a structure. Multiple readings provide a better picture than one isolated measurement. 6. Record the Results For project work, recorded measurements can be extremely useful. What Should a DFT Inspection Record Include? Depending on the project, useful information can include: Project name Component identification Location Coating system Measurement point DFT reading Date Inspector/operator Instrument identification Acceptance requirement Remarks This creates traceability and makes it easier to investigate problems later. Why One Reading Is Not Enough Consider a large steel beam. Coating thickness can vary along: Different faces Edges Corners Weld areas Difficult spray locations Different sections of the beam One measurement cannot necessarily represent the entire component. For contractual work, follow the required inspection procedure regarding the number and distribution of readings. Can TA522A Be Used for Structural Steel? The TA522A supports suitable coating measurements over ferrous steel within its specified measurement range. This makes structural steel an important potential application. However, contractors should always check whether the project specifies particular requirements regarding: Gauge type Accuracy Calibration Verification Standards compliance Measurement procedure Reporting Do not assume that every portable coating thickness gauge automatically satisfies every contractual specification. What About Aluminium? Painting contractors may occasionally work with coated aluminium components. For compatible non-ferrous conductive substrates, the TA522A supports eddy current measurement. This gives the instrument broader application coverage than an Fe-only gauge. A contractor handling both steel and aluminium can therefore use the same instrument for many suitable applications. What About Galvanized Steel? Galvanized steel introduces an additional zinc layer: Steel → Zinc and painted galvanized steel may be: Steel → Zinc → Paint The TA522A includes Fe+Zn measurement capability, with TASI specifying an Fe+Zn range of 3500 μm. However, multilayer applications need to be interpreted carefully. If the project involves galvanized steel with an additional coating, identify exactly which layer or total thickness needs to be measured before selecting the measurement procedure. TA521A vs TA522A for Painting Contractors Both models provide: 02000 μm general measurement range ±(3% + 1 μm) stated accuracy Fe measurement NFe measurement Automatic substrate recognition Fe+Zn capability For general or occasional coating measurements, the TA521A can be considered. For painting contractors performing regular DFT inspection, we generally prefer the TA522A because it provides additional manual measurement mode selection. This can be useful when a contractor is repeatedly measuring the same known steel substrate across a project. Who Should Consider the TA522A? Potential users include: Industrial painting contractors Protective coating contractors Steel contractors Maintenance contractors Steel fabricators Factory maintenance teams QC personnel Engineering companies Inspection teams For these users, a portable DFT gauge can provide quick measurements both in the workshop and at the project site. Can DFT Measurement Reduce Rework? It cannot prevent every coating problem. However, routine internal measurement can identify thickness problems before final handover. For example: Coating Applied ↓ Internal DFT Measurement ↓ Low / High Readings Identified ↓ Investigate Cause ↓ Corrective Action ↓ Recheck ↓ Final Inspection This makes coating thickness measurement useful as part of process control rather than only as a final acceptance test. Common Contractor Mistakes Waiting Until Final Inspection Internal QC before formal inspection can reduce surprises. Taking Only One Reading Large structures normally require multiple measurement locations according to the applicable procedure. Not Knowing the Required DFT A reading has little meaning without an acceptance criterion. Ignoring the Substrate Steel, aluminium and galvanized steel require different consideration. Assuming the Gauge Decides Pass or Fail The instrument measures thickness. The project specification or applicable standard determines acceptance. Buying a Gauge Without Checking Project Requirements For contractual inspection, always confirm required specifications before purchasing. FAQ What is a DFT gauge used for? A DFT gauge measures dry film thickness on suitable coating/substrate combinations after the coating has dried or cured. Why should painting contractors measure DFT before handover? Internal DFT checks can help identify coating thickness issues before formal client or third-party inspection. Can TASI TA522A measure paint on steel? Yes. It supports magnetic induction measurement for suitable coatings over compatible ferrous steel substrates. What is the TA522A measurement range? The specified general measurement range is 02000 μm. Can TA522A measure coatings on aluminium? Yes, for suitable coatings over compatible conductive non-ferrous substrates using the eddy current principle. Is TA522A suitable for every project specification? Not automatically. Contractual projects may specify particular instrument, calibration, accuracy, standard or inspection requirements. Check the project documentation before selecting a gauge. Which is better for contractors, TA521A or TA522A? For frequent professional work, we generally prefer the TA522A because of its additional measurement mode control. For straightforward general measurement, the TA521A can also be considered. Looking for a DFT Gauge for Painting Contractor Work in Malaysia? If you are preparing for a coating project, tell MTM Precision: What are you painting? What is the substrate? What DFT range is specified? What project or inspection requirement must you meet? MTM Precision supplies coating thickness and industrial testing instruments for contractors, fabricators, factories and engineering companies in Malaysia. For general portable Fe/NFe coating measurement, the TASI TA522A is one model worth considering. Contact MTM Precision MTM Precision Sdn Bhd No. 29-1 & 29-2, Jalan Bandar 18 Pusat Bandar Puchong 47160 Puchong, Selangor, Malaysia Website: www.mtmpre.com.my WhatsApp: +6016-660 7346 Email: mtmpre@yahoo.com
26 Aug 2026
