18. May 2021
© Copyright 2020, PROCEQ SA
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7 Practical measuring suggestions
7.1 General
Always indicate the used measuring geometry for all measurements.
Measurements of different measuring geometries cannot be compared and cannot be
“converted” from one geometry into another. Therefore a series of measurement must
always be taken with the same measuring geometry.
7.2 How to choose the correct measuring geometry for paints and varnishes
The following explanations apply to smooth coated surfaces, they do not fully apply for metallic
and textured coatings or uneven surfaces. They do not apply at all for other surfaces such as
foils, metals, textiles and paper.
According to the standard ISO 2813 and ASTM D523 the correct measuring geometry should
be determined by a pre - measurement taken at 60°. Related to that the correct measuring
geometry can be determined with the table below.
ISO 2813
ASTM D523
Value @ 60°
Geometry
>70 GU
20°
10 GU
–
70 GU
60°
<10 GU
85°
Value @ 60°
Geometry
>70 GU
20°
10 GU
–
70 GU
60°
<10 GU
85°
7.3 Measuring special samples
Depending on the application area, shape and size of the measuring samples (uneven or very
small surfaces), it is possible that a holder or positioning support for the precise positioning of
the ZGM 1120 is needed in order to get reproducible measuring values.
The following shows an example, which can serve as an example for your own holder.
Positioning support example for measurements on small parts
