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Certified reference standardsBog'liq 27608-разблокирован DALINA, Abdulla Qahhor. Paqir qo\'mondonlari5.2
Certified reference standards. Certified glass or liquid reference standards with defined or traceable
Lovibond
®
colour values and optical path length details are suitable and can be obtained from the
manufacturers of the instruments [see footnotes 2) and 3)]. It is recommended that reference standards be
used for calibration and routine verification of automatic colorimeters, and these may assist laboratories to
conform to their good laboratory practice requirements and ISO/IEC 17025
[6]
and ISO 9000
[4]
procedures.
5.3
Optical glass sample cells, made of good quality optical glass and with a good standard finish. The
following optical path lengths may be used, or results expressed as equivalent to these lengths:
1,6 mm (1/16 inch);
3,2 mm (1/8 inch);
6,4 mm (1/4 inch);
12,7 mm (1/2 inch);
25,4 mm (1 inch);
76,2 mm (3 inch);
133,4 mm (5
1/4
inch).
Borosilicate optical glass cells should be used if cells are subjected to thermal shock, in particular during the
heating or measurement of hot samples.
6 Sampling
Sampling is not part of the method specified in this International Standard. A recommended sampling method
is given in ISO 5555
[1]
.
It is important the laboratory receive a truly representative sample which has not been damaged or changed
during transport or storage.
7 Preparation of test sample
7.1 General
Prepare the sample in accordance with ISO 661. The fat or oil shall be completely liquid, clear, bright, and free
from turbidity when the determination is performed.
2) LICO
200, LICO
300, LICO
400, and LICO
500 are trade names of products supplied by Hach Lange
(
http://www.hach-lange.com
). This information is given for the convenience of users of this International Standard and
does not constitute an endorsement by ISO of these products.
3) PFX
880/L, PFX
950, and PFX
995 are trade names of products supplied by The Tintometer Ltd
(
http://www.tintometer.com
). This information is given for the convenience of users of this International Standard and does
not constitute an endorsement by ISO of these products.
O‘z DSt ISO 27608:2017 (ISO 27608:2010, IDT)
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