Resources
DONGRU app
Connect your DONGRU instruments, capture readings and generate reports straight from your phone.
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Instrument Selection
Selecting a Gloss Meter: the 60° Universal Angle, Tri-Angle and Small-Aperture Measurement
Gloss is a relative quantity and must be compared at the same incidence angle; 60° is the universal angle, 20° suits high-gloss surfaces and…
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Instrument Selection
Selecting a Transmittance Meter: Split Portable, Benchtop and Tri-Path Optics
Transmittance meters split by form into split portable (suited to vehicle windows and field measurement), benchtop (suited to lenses and small workpieces) and tri-path-optics…
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Instrument Selection
Selecting an Ultrasonic Thickness Gauge: General-Purpose, Wide-Range, Coating-Penetrating and Ultra-Thin Single-Crystal
Ultrasonic thickness gauges divide by capability into four classes: general-purpose covers routine wall thickness, wide-range covers thick walls and high accuracy, coating-penetrating covers painted…
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Instrument Selection
Dry Batteries or Built-in Li-ion: How to Choose the Power Supply
Dry-battery models are low cost, replaceable on site and suit low frequency and remote work; built-in Li-ion models need no replacement and suit high-frequency…
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Instrument Selection
How to Choose the Measuring Range: What 1250 / 2000 / 3000 / 6000μm / 15mm Each Map To
Range selection follows the "typical thickness in the 20%-80% band" rule. Common coating-thickness bands are 0-1250μm (thin coatings and anodising), 0-2000μm (general industrial), 0-3000/5000μm…
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Instrument Selection
Selecting a Coating Thickness Gauge in 7 Steps: Turn Selection Into Questions You Can Answer
The correct order is: substrate material → coating type → thickness range → working environment → accuracy requirement → data capability → compliance and…
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Industry Standards
NIST Traceability and Calibration Certificates: Normal Form vs Long Form
A calibration certificate is the pass to get a coating thickness gauge onto a professional procurement list. US standards require dry-film gauges to carry…
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Industry Standards
ASTM D6132-13(2022): The US Standard for Ultrasonic Coating Thickness Measurement
ASTM D6132-13(2022) specifies the nondestructive measurement of applied organic coatings using an ultrasonic coating thickness gauge, aimed specifically at non-metallic substrates (plastic, wood, FRP,…
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Industry Standards
ISO 12944 Series: Steel Structure Anti-Corrosion Paint Systems and Corrosivity Categories C1-C5
ISO 12944 is a set of 9-part specifications for anti-corrosion paint systems on steel structures: Part 2 defines atmospheric corrosivity categories C1 (very low)…
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Industry Standards
ISO 19840:2012 vs SSPC-PA 2: Two Rough-Surface Acceptance Rules Compared
ISO 19840:2012 specifies thickness measurement and acceptance criteria for coatings on rough steel surfaces. Like SSPC-PA 2-2022 it shares the 80/20 judgment logic, but…
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Industry Standards
ISO 2808:2019: The Umbrella Specification for Paint Film Thickness Determination
ISO 2808:2019 is the umbrella specification for paint film thickness determination, bringing all measurement methods for wet film, dry film, uncured powder coatings and…
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Industry Standards
ISO 2360:2017: Eddy-Current Measurement of Non-Conductive Coatings on Non-Magnetic Conductive Substrates
ISO 2360:2017 specifies the amplitude-sensitive eddy-current method for measuring non-conductive coatings (paint, anodized film, plastic, powder, enamel) on non-magnetic conductive metal substrates (aluminium, copper,…