ISO 14782:2021

INTERNATIONAL ISO
STANDARD 14782
Second edition
2021-10
Plastics — Determination of haze for
transparent materials
Plastiques — Détermination du trouble des matériaux transparents
Reference number
© ISO 2021
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Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 1
5 Apparatus . 2
6 Specimens. 3
7 Conditioning . 4
8 Procedure .4
9 Expression of results . 4
10 Precision . 5
11 Test report . 6
Bibliography . 7
iii
Foreword
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This document was prepared by Technical Committee ISO/TC 61, Plastics, Subcommittee SC 5, Physical-
chemical properties.
This second edition cancels and replaces the first edition (ISO 14782:1999), which has been technically
revised. It also incorporates the Technical Corrigendum ISO 14782:1999/Cor 1:2005.
The main changes compared to the previous edition are as follows:
— Formula (1) in Clause 9 has been corrected;
— the document has been editorially revised.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.
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INTERNATIONAL STANDARD ISO 14782:2021(E)
Plastics — Determination of haze for transparent materials
1 Scope
This document specifies a method for the measurement of haze, an optical property resulting from
wide-angle scattering of light, in transparent and substantially colourless plastics. This method is
applicable to the measurement of haze values of less than 40 %.
NOTE The haze of abraded or matted transparent plastics can be measured, but the value obtained can be
erroneously lower than the true value due to light scattering within a narrow angle.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 472, Plastics — Vocabulary
ISO 291, Plastics — Standard atmospheres for conditioning and testing
ISO/CIE 11664-1, Colorimetry — Part 1: CIE standard colorimetric observers
ISO 11664-2, Colorimetry — Part 2: CIE standard illuminants
ISO 13468-1, Plastics — Determination of the total luminous transmittance of transparent materials —
Part 1: Single-beam instrument
CIE Publication No. 15, Colorimetry
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 472 and ISO 13468-1 apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
4 Principle
Haze is determined using an integrating sphere the efficiency of which is held constant by compensation.
5 Apparatus
5.1 The apparatus shall consist of a stabilized light source, an associated optical system, an
integrating sphere with ports, and a photometer comprising a photodetector, signal processor and
display unit or recorder (see Figure 1).
Key
1 lamp 6 exit port
2 lens 7 entrance port
3 baffle 8 integrating sphere
4 photodetector 9 compensation port
5 light trap 10 specimen holder
Figure 1 — Schematic arrangement of the apparatus
5.2 The light source and the photometer shall be used in conjunction with a filter to provide an output
corresponding to the photopic standard luminous efficiency Vë() (as defined in ISO/CIE 11664-1),
which is identical to the colour-matching function yë specified in ISO/CIE 11664-1 under CIE standard
()
illuminant D as specified in ISO 11664-2. The output of the photodetector shall be proportional to
the incident flux, to within 1 % of the incident flux, over the range used.
The spectral and photometric characteristics of the light source and photometer shall be kept constant
during measurements.
5.3 The light source and its associated optical system shall produce a parallel light beam, no ray of
which makes an angle of more than 0,05 rad (3°) with the beam axis. This beam shall not be vignetted
at either port of the integrating sphere.
5.4 The design of the instrument shall be such that the reading is zero in the absence of the light
beam.
5.5 The integrating sphere used to collect the transmitted light may be of any diameter (but
preferably no less than 150 mm in order to be able to accommodate large specimens), as long as the
total port area does not exceed 3,0 % of the internal reflecting area of the sphere.
5.6 The integrating sphere shall have an entrance port, an exit port, a compensation port and a
photodetector port (see Figure 1). The entrance and exi
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