EN ISO 10339:1999
(Main)Ophthalmic optics - Contact lenses - Determination of water content of hydrogel lenses (ISO 10339:1997)
Ophthalmic optics - Contact lenses - Determination of water content of hydrogel lenses (ISO 10339:1997)
Specification of a uniform test procedure in order to achieve comparable test results.
Augenoptik - Kontaktlinsen - Bestimmung des Wassergehalts von Hydrogelkontaktlinsen (ISO 10339:1997)
Diese Internationale Norm beschreibt Verfahren zur Bestimmung des Wassergehalts von Hydrogelkontaktlinsen. Sie legt die Vorgehensweise bei der Durchführung der Messungen und die Bedingungen, unter denen diese Messungen vorzunehmen sind, fest.
Optique ophtalmique - Lentilles de contact - Détermination de la teneur en eau des lentilles en hydrogel (ISO 10339:1997)
La CEI 62271-105:2012 est applicable aux appareils tripolaires utilisés dans les réseaux de distribution publics ou les installations industrielles qui forment des ensembles fonctionnels composés d'interrupteurs ou d'interrupteurs-sectionneurs et de fusibles limiteurs de courant, conçus pour être capable de
- couper, à la tension de rétablissement assignée, tous les courants jusqu'au pouvoir de coupure assigné inclus;
- établir, à la tension assignée, des circuits pour lesquels le pouvoir de coupure assigné s'applique.
Elle ne s'applique ni aux combinés disjoncteurs-fusibles, ni aux contacteurs-fusibles, ni aux combinés destinés à la manoeuvre et à la protection des moteurs ou des batteries de condensateurs. Cette deuxième édition annule et remplace la première édition de la CEI 62271-105, publiée en 2002, et constitue une révision technique.
Cette édition inclut les modifications techniques majeures suivantes par rapport à l'édition précédente:
- la mise en place des figures aux endroits où elles sont citées en premier;
- la renumérotation des tableaux;
- l'ajout, en partie, de propositions issues du document 17A/852/INF de la CEI;
- l'ajout de paragraphes manquants de la CEI 62271-1;
- l'introduction du 6.105 "Extension de la validité des essais de type" et en conséquence, suppression des parties correspondantes dans les différents articles existants;
- la modification du septième alinéa du 6.101.4, du fait qu'il y a maintenant une définition des NSDD (décharges disruptives non soutenues) donnée au 3.7.4 de la CEI 62271 1:2007. Harmonisation avec la CEI 62271-107;
- certains articles référencés dans d'autres normes, comme dans la CEI 60282-1, ont été modifiés, si bien que les éditions indiquées au 1.2 ont été modifiées en consequence;
- l'ajout d'une nouvelle Annexe C définissant les tolérances.
Cette publication doit être lue conjointement avec la CEI 62271-1:2007.
Očesna optika - Kontaktne leče - Določevanje vode v lečah iz hidrogela (ISO 10339:1997)
General Information
Relations
Standards Content (Sample)
SLOVENSKI STANDARD
SIST EN ISO 10339:2000
01-januar-2000
2þHVQDRSWLND.RQWDNWQHOHþH'RORþHYDQMHYRGHYOHþDKL]KLGURJHOD ,62
Ophthalmic optics - Contact lenses - Determination of water content of hydrogel lenses
(ISO 10339:1997)
Augenoptik - Kontaktlinsen - Bestimmung des Wassergehalts von Hydrogelkontaktlinsen
(ISO 10339:1997)
Optique ophtalmique - Lentilles de contact - Détermination de la teneur en eau des
lentilles en hydrogel (ISO 10339:1997)
Ta slovenski standard je istoveten z: EN ISO 10339:1999
ICS:
11.040.70 Oftalmološka oprema Ophthalmic equipment
SIST EN ISO 10339:2000 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
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SIST EN ISO 10339:2000
INTERNATIONAL IS0
STANDARD 10339
First edition
1997-09-I 5
Ophthalmic optics - Contact lenses -
Determination of water content of hydrogel
lenses
Optique ophtalmique - Lentil/es de contact - Dbtermination de la teneur
en eau des lentil/es en hydrogel
Reference number
IS0 10339: 1997(E)
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SIST EN ISO 10339:2000
IS0 10339: 1997(E)
Foreword
IS0 (the International Organization for Standardization) is a worldwide
federation of national standards bodies (IS0 member bodies). The work of
preparing International Standards is normally carried out through IS0
technical committees. Each member body interested in a subject for which
a technical committee has been established has the right to be represented
on that committee. International organizations, governmental and non-
governmental, in liaison with ISO, also take part in the work. IS0
collaborates closely with the International Electrotechnical Commission
(IEC) on all matters of electrotechnical standardization.
Draft International Standards adopted by the technical committees are
circulated to the member bodies for voting. Publication as an International
Standard requires approval by at least 75 % of the member bodies casting
a vote.
International Standard IS0 10339 was prepared by Technical Committee
ISOITC 172, Optics and optical instruments, Subcommittee SC 7,
Ophthalmic optics and instruments.
Annex A forms an integral part of this International Standard. Annexes B
and C are for information only.
0 IS0 1997
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced
or utilized in any form or by any means, electronic or mechanical, including photocopying and
microfilm, without permission in writing from the publisher.
International Organization for Standardization
Case postale 56 l CH-1211 Geneve 20 l Switzerland
Internet central @ iso.ch
x.400 c=ch; a=400net; p=iso; o=isocs; s=central
Printed in Switzerland
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SIST EN ISO 10339:2000
INTERNATIONAL STANDARD o Is0 IS0 10339: 1997(E)
Ophthalmic optics - Contact lenses - Determination of water
content of hydrogel lenses
1 Scope
This International Standard describes methods for the determination of water content of hydrogel contact lenses. It
specifies the procedures for making the measurements and establishes the conditions under which the
measurements are to be made.
2 Normatives references
The following standards contain provisions which, through reference in this text, constitute provisions of this
International Standard. All standards are subject to revision, and parties to agreements based on this International
Standard are encouraged to investigate the possibility of applying the most recent editions of the standards
indicated below. Members of IEC and IS0 maintain registers of currently valid International Standards.
IS0 8320:1986, Optics and optical instruments - Contact lenses - Vocabulary and symbols.
IS0 10344:1996, Optics and optical instruments - Contact lenses - Saline solution for contact lens testing.
3 Definitions
For the purposes of this International Standard, the definitions given in IS0 8320:1986 and the following definition
apply*
3.1 water content, WHzo
Amount of water (expressed as percent by mass fraction) present in a hydrated hydrogel contact lens which is fully
equilibrated with saline solution under specified conditions of temperature.
mH,O
=-x100
WH20 (%)
miens
where
mH20 is the mass of water;
miens is the mass of the hydrated lens.
In this context, dissolved solutes such as sodium chloride and buffers contribute to the mass of the hydrated lens.
NOTE -
1
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SIST EN ISO 10339:2000
@ IS0
IS0 10339: 1997(E)
4 Procedure
The water content shall be determined by the method given in annex A.
NOTE - The methods given in annexes B and C are informative and may be used for quality control purposes only.
5 Test report
The test report shall include the following information:
a) a reference to this International Standard, i.e. IS0 10339;
b) the test method used, i.e. method given in annex A as well as, if used, the method given in annex B or C;
c) identification of the material under test;
d) the mean water content (result) of the sample, in percent (mass fraction);
e) the number of samples tested and the number of determinations per sample;
f) the date of the test.
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SIST EN ISO 10339:2000
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Annex A
(normative)
Gravimetric determination of water content of hydrogel lens by loss
,
on drying using conventional oven
A.1 Principle
Test hydrogel lenses in their fully hydrated state are weighed on an analytical balance. The lenses are then dried in
an oven and weighed again. The difference in masses is the mass of water lost by evaporation and represents the
mass of water present in the fully hydrated lens.
A.2 Precision
The.accuracy of this method is limited by the difficulty of reliably “wet-blotting” the lens before determining the
hydrated mass. To minimize the error in blotting technique, the mass of the hydrated sample should be between
100 mg and 300 mg.
The result of a ring test demonstrated that multiple (3) determinations on thick polymer discs gave a tolerance of
+ 0,4 % water content. For a lens of the mass stated in this International Standard, a reproducibility on the order of
I I,0 % water content was likely. If the sample mass is less than 100 mg, more samples may be required for
measurement in order to obtain the stated reproducibility.
A.3 Apparatus
A.3.1 Analytical balance, capable of weighing to 0,l mg.
A.3.2 Laboratory oven, capable of being maintained at (105 + 5) OC.
A.3.3 Glass microscope slides.
A.3.4 Desiccator containing active desiccant (e.g. anhydrous calcium sulfate, CaS04).
A.3.5 Water bath, capable of being maintained at (20 + 0,5) OC.
A.3.6 Saline solution complying with IS0 10344.
’
A.3.7 Whatman No. 1 filter paper I); or clean dry cloth of lint-free cotton, linen or microfibre.
1) Whatman No. 1 filter paper is the tradename of a product supplied by Whatman, Inc., 9 Bridewell Place, Clifton N.J.,
USA 07014. This information is given for the convenience of users of this International Standard and does not constitute an
endorsement by IS0 of the product named. Equivalent products may be used if they can be shown to lead to the same results.
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ISO. 10339: 1997(E)
A.4 Procedure
A.4.1 Equilibrate the test lenses, suspended in saline solution, at the temperature of the water bath (20 + 0,5) OC
for at least 1 h.
A.4.2 For each test lens, dry one glass slide to constant mass in the oven. Store the dried slide in the desiccator.
Weigh the slide immediately before use (mo).
of the
A.4.3 Carry out the test at a room temperature of (20 + 0,5) OC. Carefully blot each test sample by one
following methods (see note below);
e and
a) Place the sample on a clean dry lint-free cotton, linen or microfibre cloth. Fold the cloth over the samp
absorb unimbibed water by lightly pressing three times with a finger tip.
b) Place the sample between two sheets of barely dampened Whatman No. 1 filter paper.
The purpose of blotting is to remove unimbibect water from the surface of the test sample. It is necessary to avoid
NOTE -
partial dehydration of the surface by over-blotting. Evaporation can also occur if the procedure is not carried out rapidly.
The likelihood of over-blotting is more prevalent with the dry cloth technique [A.4.3 a)] which could lead to an underestimate of
the true water content. Conversely, blotting with the dampened paper [A.4.3 b)] may not remove all surface droplets and could
lead to an overestimate of the true water content.
Thus the accuracy of the method is limited by difficulty in reliably carrying out the blotting procedure. Hence, the operator
should become proficient at the blotting technique before proceeding.
A.4.4 Immediately place the blotted lens on the previously dried and weighed glass slide. Weigh the slide and the
sample (172,).
Perform the blotting and weighing steps as quickly as possible to minimize loss of water by evaporation.
A.4.5 With the lens on
...
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