: Used for most samples. If the result is between 10 and 70 Gloss Units (GU), stick with this angle. 20° (High Gloss) : Used if the 60° reading is above 70 GU . It provides better resolution for very shiny surfaces. 85° (Low Gloss/Matte) : Used if the 60° reading is below 10 GU
The test method relies on directing a controlled beam of light at a specific angle onto a test surface and measuring the amount of light reflected into a receptor. The measurement scale is based on a polished black glass standard with a assigned specular gloss value of 100 at the specified wavelengths.
Many quality management systems (e.g., ISO 9001) require the use of the latest standards.
As of June 2025, the standard remains a critical component of global industrial inspection. You can obtain the latest PDF version through official channels:
Using the current document ensures that your quality control data matches data from international supply chains. The Three Geometry Angles Defined astm d523 pdf new
Converts the collected light energy into an electrical signal. The Scale: Gloss Units (GU)
Ratings obtained through this test method are meant to correlate directly with visual observations of surface shininess. The Three Geometries of Gloss Measurement
The glossmeter is calibrated using a black glass standard (usually provided with the meter) with a known refractive index (
In this post, we’ll break down the latest updates to ASTM D523, the testing methods, and how you can get your hands on the official documentation to perfect your surface analysis. What is ASTM D523? : Used for most samples
Specular gloss is a measure of the mirror-like appearance of a surface. It is defined as the ratio of the amount of light reflected by a surface to the amount of light incident on it, at a specific angle. Specular gloss is an important property of surfaces, as it can affect their appearance, durability, and functionality.
Both standards are very similar in their technical content and often harmonized. ASTM D523 primarily specifies measurements in inch-pound units with SI units as a secondary conversion, while ISO 2813 is primarily in SI units. For most practical gloss measurements, the two methods are considered technically equivalent, though the exact wording and some procedural notes may differ.
The glossmeter must be calibrated before use using a black glass standard, which is typically supplied with the instrument.
The core of ASTM D523 lies in its three-angle measurement system. Selecting the correct geometry is vital for achieving accurate and reliable data. It provides better resolution for very shiny surfaces
Nonmetallic specimens (e.g., paints, plastics, coatings).
The reference standard is assigned a value of exactly
is the official Standard Test Method for Specular Gloss. Published by ASTM International, this test method is primarily utilized to measure the specular (mirror-like) reflectance of non-metallic specimens. Gloss is typically associated with a surface's capacity to reflect more light in directions close to the specular angle than in other directions.
The glossmeter is placed firmly on the surface. At least three separate readings are taken at different locations across the specimen to account for any localized surface variations.
This public link is valid for 7 days and shares a thread, including any personal information you added. This link or copies made by others cannot be deleted. If you share with third parties, their policies apply. Can’t copy the link right now. Try again later. D523 Standard Test Method for Specular Gloss - ASTM