Resources
DONGRU app
Connect your DONGRU instruments, capture readings and generate reports straight from your phone.
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Technical Articles
The Coating Quality Control Loop: From Wet Film to Dry Film
Coating quality control is a data chain: before application, set surface preparation and material parameters; during application, monitor wet film thickness and environmental conditions;…
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Technical Articles
Technical Comparison of Three Thin Layers: Galvanising, Anodising and Conformal Coating
Although galvanising, anodic coating and conformal coating are all thin layers, their substrate and coating natures differ: galvanising (steel substrate + non-magnetic coating) uses…
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Technical Articles
Introduction to Measurement Uncertainty: Reading the “±” on the Calibration Certificate
Measurement uncertainty is a quantitative expression of the confidence interval of a measurement result; it is synthesised from several components (instrument, reference foil, environment,…
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Technical Articles
Coating Failure Investigation: What Thickness Data Can Reveal
In coating failure investigation, thickness measurement is used to judge insufficient film thickness (leading to early failure) or over-thickness (leading to cracking and loss…
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Technical Articles
The NDT Methods Landscape: Where Thickness Measurement Fits In
Non-destructive testing (NDT) includes ultrasonic, radiographic, magnetic particle, penetrant, eddy current, visual and other methods; thickness measurement is a branch of the ultrasonic and…
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Technical Articles
Recording and Using Measurement Data: From Readings to Usable Quality Data
The storage and statistics of a coating thickness gauge turn scattered readings into usable quality data: the average supports acceptance, the extreme values flag…
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Technical Articles
Why Readings Drift: A Complete Decomposition of Coating Thickness Error Sources
Coating thickness error falls into five categories: instrument error (calibration status, temperature drift), operator error (contact pressure, coupling, angle), workpiece error (substrate material, roughness,…
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Technical Articles
mil vs μm: Unit Conversion and US Engineering Convention
1 mil = 25.4 μm. International standards use SI units (μm, mm) as the basis, with imperial units in parentheses only as reference; but…
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Technical Articles
The Full Picture of Coating Thickness Principles: Eight Technical Routes from Magnetic to X-Ray
There are eight mainstream routes to coating thickness measurement: magnetic, eddy current, ultrasonic, magnetic pull-off, micrometer, coulometric, X-ray fluorescence and photothermal. Of these, magnetic,…
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FAQ
Use and Maintenance FAQ: Troubleshooting and Care
Daily care of a thickness gauge centres on four parts: the probe (wear part), the foil (needs verification), the battery (affects stability) and the…
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FAQ
Procurement and Certification FAQ: Certificates, Certifications and Market Access
The two "passes" into the professional market are a traceable calibration certificate and a declaration of conformity to standards; also, products with wireless modules…
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FAQ
Visible Light Transmittance (VLT) and State Laws FAQ: Window-Tint Compliance
US window tint is legislated state by state; the most common front-side limit is 35%, with some states requiring 50% or 70%. Because factory…