Dentistry - Gypsum products (ISO 6873:2013)

This International Standard gives a classification of, and specifies requirements for, gypsum products used for dental purposes such as making oral impressions, moulds, casts, dies or model bases, and mounting models. It specifies the test methods to be employed to determine compliance with these requirements. It also includes requirements for the labelling of packaging and for adequate instructions to accompany each package. This International Standard does not apply to dental bone graft substitutes composed of calcium sulphate hemihydrate (or gypsum).

Zahnheilkunde - Gipse (ISO 6873:2013)

In dieser Internationalen Norm werden Anforderungen festgelegt und eine Typeneinteilung der Gipse vorgenommen, die in der Zahnheilkunde Anwendung finden, wie zum Beispiel bei der Abdrucknahme und der Herstellung von Modellen, Abgüssen, Formen oder Modellsockeln und Montagemodellen. Diese Norm beschreibt die anzuwendenden Prüfverfahren, um die Konformität mit diesen Anforderungen festzustellen. Außerdem enthält sie Anforderungen an die Etikettierung der Verpackungen und an die entsprechende Gebrauchsanweisung, die jeder Packung beizufügen ist.
Diese Internationale Norm gilt nicht für Knochentransplantatersatz für zahnärztliche Zwecke, der aus Calciumsulfat Halbhydrat (oder Dentalgips) besteht.

Médecine bucco-dentaire - Produits à base de gypse (ISO 6873:2013)

L'ISO 6873:2013 donne une classification et spécifie des exigences applicables aux produits à base de gypse utilisés à des fins dentaires, tels que la prise d'empreintes buccales, la fabrication de moules, de moulages, de matrices ou de bases de modèles et le montage de modèles. Elle spécifie les méthodes d'essai à appliquer pour déterminer la conformité à ces exigences. Elle inclut également des exigences concernant l'étiquetage des emballages et les instructions appropriées à joindre à chaque emballage.

Zobozdravstvo - Mavčni izdelki (ISO 6873:2013)

Ta mednarodni standard podaja razvrstitev in določa zahteve za mavčne izdelke, ki se uporabljajo v zobozdravstvene namene, npr. za izdelovanje dentalnih odlitkov, zlitin, ulitkov, matric ali osnov za modele ter modelov za pritrjevanje. Določa preskusne metode za uporabo pri ugotavljanju skladnosti s temi zahtevami. Vključuje tudi zahteve za označevanje embalaže in za ustreznost spremnih navodil, ki morajo biti priložena vsakemu izdelku. Ta mednarodni standard ne velja za dentalne nadomestke čeljustne kosti, sestavljene iz kalcijevega sulfata hemihidrata (ali mavca).

General Information

Status
Published
Public Enquiry End Date
19-Feb-2012
Publication Date
20-Aug-2013
Technical Committee
Current Stage
6060 - National Implementation/Publication (Adopted Project)
Start Date
13-Jun-2013
Due Date
18-Aug-2013
Completion Date
21-Aug-2013

Relations

Buy Standard

Standard
EN ISO 6873:2013
English language
27 pages
sale 10% off
Preview
sale 10% off
Preview
e-Library read for
1 day
Draft
prEN ISO 6873:2012 - BARVE
English language
28 pages
sale 10% off
Preview
sale 10% off
Preview
e-Library read for
1 day

Standards Content (Sample)

SLOVENSKI STANDARD
SIST EN ISO 6873:2013
01-september-2013
1DGRPHãþD
SIST EN ISO 6873:2000
=RER]GUDYVWYR0DYþQLL]GHONL ,62
Dentistry - Gypsum products (ISO 6873:2013)
Zahnheilkunde - Gipse (ISO 6873:2013)
Médecine bucco-dentaire - Produits à base de gypse (ISO 6873:2013)
Ta slovenski standard je istoveten z: EN ISO 6873:2013
ICS:
11.060.10 =RERWHKQLþQLPDWHULDOL Dental materials
SIST EN ISO 6873:2013 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

---------------------- Page: 1 ----------------------

SIST EN ISO 6873:2013

---------------------- Page: 2 ----------------------

SIST EN ISO 6873:2013


EUROPEAN STANDARD
EN ISO 6873

NORME EUROPÉENNE

EUROPÄISCHE NORM
April 2013
ICS 11.060.10 Supersedes EN ISO 6873:2000
English Version
Dentistry - Gypsum products (ISO 6873:2013)
Médecine bucco-dentaire - Produits à base de gypse (ISO Zahnheilkunde - Gipse (ISO 6873:2013)
6873:2013)
This European Standard was approved by CEN on 21 March 2013.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European
Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national
standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN member.

This European Standard exists in three official versions (English, French, German). A version in any other language made by translation
under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management Centre has the same
status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United
Kingdom.





EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2013 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 6873:2013: E
worldwide for CEN national Members.

---------------------- Page: 3 ----------------------

SIST EN ISO 6873:2013
EN ISO 6873:2013 (E)
Contents Page
Foreword .3

2

---------------------- Page: 4 ----------------------

SIST EN ISO 6873:2013
EN ISO 6873:2013 (E)
Foreword
This document (EN ISO 6873:2013) has been prepared by Technical Committee ISO/TC 106 "Dentistry" in
collaboration with Technical Committee CEN/TC 55 “Dentistry” the secretariat of which is held by DIN.
This European Standard shall be given the status of a national standard, either by publication of an identical
text or by endorsement, at the latest by October 2013, and conflicting national standards shall be withdrawn at
the latest by October 2013.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent rights.
This document supersedes EN ISO 6873:2000.
According to the CEN-CENELEC Internal Regulations, the national standards organizations of the following
countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech
Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece,
Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal,
Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom.
Endorsement notice
The text of ISO 6873:2013 has been approved by CEN as EN ISO 6873:2013 without any modification.

3

---------------------- Page: 5 ----------------------

SIST EN ISO 6873:2013

---------------------- Page: 6 ----------------------

SIST EN ISO 6873:2013
INTERNATIONAL ISO
STANDARD 6873
Third edition
2013-04-01
Dentistry — Gypsum products
Médecine bucco-dentaire — Produits à base de gypse
Reference number
ISO 6873:2013(E)
©
ISO 2013

---------------------- Page: 7 ----------------------

SIST EN ISO 6873:2013
ISO 6873:2013(E)

COPYRIGHT PROTECTED DOCUMENT
© ISO 2013
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form
or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior
written permission. Permission can be requested from either ISO at the address below or ISO’s member body in the country of
the requester.
ISO copyright office
Case postale 56 • CH-1211 Geneva 20
Tel. + 41 22 749 01 11
Fax + 41 22 749 09 47
E-mail copyright@iso.org
Web www.iso.org
Published in Switzerland
ii © ISO 2013 – All rights reserved

---------------------- Page: 8 ----------------------

SIST EN ISO 6873:2013
ISO 6873:2013(E)

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Classification . 1
5 Requirements . 2
5.1 Quality . 2
5.2 Fluidity at pouring time (Type 1 materials only) . 2
5.3 Setting time . 2
5.4 Linear setting expansion . 2
5.5 Fracture (Type 1 materials only) . 2
5.6 Compressive strength . 2
5.7 Reproduction of detail . 2
6 Testing — Generalities . 3
6.1 Sampling . 3
6.2 Test conditions . 3
6.3 Mixing method . 3
7 Test methods . 3
7.1 Visual inspection . 3
7.2 Fluidity at pouring time for Type 1 materials . 3
7.3 Setting time . 4
7.4 Linear setting expansion . 7
7.5 Fracture .12
7.6 Compressive strength .12
7.7 Reproduction of detail .13
8 Packaging, marking and information to be supplied by the manufacturer .18
8.1 Packaging .18
8.2 Labelling .18
8.3 Instructions for use .19
© ISO 2013 – All rights reserved iii

---------------------- Page: 9 ----------------------

SIST EN ISO 6873:2013
ISO 6873:2013(E)

Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO 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.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. 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.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights.
Specific qualitative and quantitative requirements for freedom from biological hazard are not included
in this International Standard but it is recommended that, in assessing possible biological hazards,
reference should be made to ISO 10993-1 and ISO 7405.
ISO 6873 was prepared by Technical Committee ISO/TC 106, Dentistry, Subcommittee SC 2,
Prosthodontic materials.
This third edition cancels and replaces the second edition (ISO 6873:1998) of which Clause 4 and
subclauses 5.4 and 8.2 have been technically revised. An alternative design for the extensometer used
to measure setting expansion is included.
iv © ISO 2013 – All rights reserved

---------------------- Page: 10 ----------------------

SIST EN ISO 6873:2013
ISO 6873:2013(E)

Introduction
This revision was necessary because gypsum products have been marketed since the last edition of
ISO 6873 was published, which have properties (required for newly introduced dental technology) for
which the requirements set in that edition were not appropriate. In this edition the classification has
been altered to take this into account and in so doing, requirements have been set appropriately. In
addition there was concern that Type 4 dental stone used for CAD/CAM models should not produce
significant setting expansion at times beyond the 2 h period at which setting expansion was measured
and a requirement had been set. In this edition the setting expansion for Type 4 dental stone is measured
at 24 h as well.
© ISO 2013 – All rights reserved v

---------------------- Page: 11 ----------------------

SIST EN ISO 6873:2013

---------------------- Page: 12 ----------------------

SIST EN ISO 6873:2013
INTERNATIONAL STANDARD ISO 6873:2013(E)
Dentistry — Gypsum products
1 Scope
This International Standard gives a classification of, and specifies requirements for, gypsum products
used for dental purposes such as making oral impressions, moulds, casts, dies or model bases, and
mounting models. It specifies the test methods to be employed to determine compliance with these
requirements. It also includes requirements for the labelling of packaging and for adequate instructions
to accompany each package.
This International Standard does not apply to dental bone graft substitutes composed of calcium sulfate
hemihydrate (or gypsum).
2 Normative references
The following referenced documents are indispensable for the application 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 1302, Geometrical Product Specifications (GPS) — Indication of surface texture in technical product
documentation
ISO 1942, Dentistry — Vocabulary
ISO 3696:1987, Water for analytical laboratory use — Specification and test methods
ISO 8601, Data elements and interchange formats — Information interchange — Representation of
dates and times
ISO 15223-1, Medical devices — Symbols to be used with medical device labels, labelling and information to
be supplied — Part 1: General requirements
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 1942 and the following apply.
3.1
gypsum product
dental product composed essentially of a hemihydrate of calcium sulfate and any necessary modifiers
Note 1 to entry: Colouring matter and flavouring, if present, are regarded as necessary modifiers.
4 Classification
The five types of gypsum product used in dentistry are classified in accordance with this International
Standard as follows:
a) Type 1: Dental plaster for impressions;
b) Type 2: Dental plaster for mounting (Class 1) and for models (Class 2);
c) Type 3: Dental stone for models;
d) Type 4: Dental stone (high strength, low expansion) for dies, model bases and CAD/CAM dies;
© ISO 2013 – All rights reserved 1

---------------------- Page: 13 ----------------------

SIST EN ISO 6873:2013
ISO 6873:2013(E)

e) Type 5: Dental stone (high strength, high expansion) for dies when this degree of expansion is
necessary for shrinkage compensation of some materials used in dental restoration.
5 Requirements
5.1 Quality
When tested according to 7.1, the powder shall be uniform and free from foreign matter and lumps. When
mixed according to the manufacturer’s instructions the product shall produce a homogeneous mix.
5.2 Fluidity at pouring time (Type 1 materials only)
When tested according to 7.2 at a pouring time of 1,25 min, the fluidity of type 1 materials shall be equal
to or greater than 70 mm.
5.3 Setting time
When tested according to 7.3, the setting time of type 1 materials shall be in the range of 2,5 min to
5,0 min and the setting time of all material types shall be within 20 % of the value claimed by the
manufacturer in 8.2.1 h) or 8.2.2 h), whichever is appropriate for the packaging in which the product is
supplied. If the manufacturer claims a range of setting time, then the midpoint of this range is taken as
the value claimed by the manufacturer.
5.4 Linear setting expansion
When tested according to 7.4, the linear setting expansion shall be within the range listed in Table 1.
Table 1 — Linear setting expansion and compressive strength
Type Linear setting expansion Compressive strength
% MPa
2 h 24 h 1 h
min. max. min. max. min. max.
1 0,00 0,15 - - 4,0 8,0
2 (Class 1) 0,00 0,05 - - 9,0 -
2 (Class 2) 0,06 0,30 - - 9,0 -
3 0,00 0,20 - - 20,0 -
4 0,00 0,15 0,00 0,18 35,0 -
5 0,16 0,30 - - 35,0 -
5.5 Fracture (Type 1 materials only)
When tested according to 7.5, Type 1 impression plaster shall break with a clean fracture and be readily
reassembled to form the shape and size of the original unbroken specimen.
5.6 Compressive strength
When tested according to 7.6, the compressive strength shall meet the requirement(s) of Table 1.
5.7 Reproduction of detail
Types 1 and 2: When tested according to 7.7, groove c in Figure 6 shall be reproduced.
Types 3, 4 and 5: When tested according to 7.7, groove a in Figure 6 shall be reproduced.
2 © ISO 2013 – All rights reserved

---------------------- Page: 14 ----------------------

SIST EN ISO 6873:2013
ISO 6873:2013(E)

6 Testing — Generalities
6.1 Sampling
Select the material for testing from one lot that has been produced for retail and that is not beyond
its expiry date [8.2.1 b) or 8.2.2 b), whichever is appropriate for the packaging in which the product is
supplied]. Do not use powder from previously opened, broken or damaged containers.
6.2 Test conditions
Carry out all mixing and testing of the dental gypsum product at (23 ± 2) °C and (50 ± 10) % relative
humidity. Ensure that all apparatus and instruments used in mixing and testing are clean, dry and free
from particles of gypsum. Before testing begins, hold material and test apparatus at the test temperature
for a period of time that is sufficient to equilibrate with this temperature.
NOTE A minimum storage period of 15 h is recommended.
6.3 Mixing method
Mix by one of the methods (hand or mechanical) specified by the manufacturer in the instructions (see
8.3), using water, which meets the requirements of ISO 3696, Grade 3.
7 Test methods
7.1 Visual inspection
Carry out visual inspection without magnification to determine compliance with the requirements
given in 5.1, 5.5 and 5.7 (unless as stated otherwise, as in 7.7).
Determine compliance with the requirements given in Clause 8 for packaging, marking and information
supplied by the manufacturer.
7.2 Fluidity at pouring time for Type 1 materials
7.2.1 Apparatus
7.2.1.1 Cylindrical mould, constructed from a corrosion-resistant, non-absorbent material, having a
length of (50,0 ± 0,1) mm and an inside diameter of (35,0 ± 0,1) mm. Clean and dry.
7.2.1.2 Glass plate, flat and smooth, with sides of length at least 100 mm. Clean and dry.
7.2.1.3 Means of measuring lengths from 35 mm to 100 mm, for measuring the major and minor
diameters of the slumped mix to the nearest millimetre.
7.2.2 Procedure
Rest the glass plate on a surface that is free of vibration. Place the mould upright on the centre of the plate.
Add (100,0 ± 0,1) g of the sample to the manufacturer’s recommended quantity of water (ISO 3696,
Grade 3) dispensed to an accuracy of 0,1 ml to a mixing bowl and mix as described in 6.3.
Completely fill the mould and level off the mixed material so that it is flush with the top of the mould.
At 1,25 min after the start of mixing, lift the mould vertically from the plate at a rate of approximately
10 mm/s and allow the mix to slump or spread over the plate. One minute after the mould is lifted,
measure the major and minor axes of the slumped material to the nearest millimetre. Record the average
of these two diameters as the fluidity at the pouring time.
© ISO 2013 – All rights reserved 3

---------------------- Page: 15 ----------------------

SIST EN ISO 6873:2013
ISO 6873:2013(E)

7.2.3 Evaluation
Carry out the test twice. If both average values meet the requirement given in 5.2, then the product
meets the requirement for fluidity. If neither meets this requirement, then the product fails. If one
average value meets the requirement given in 5.2, and the other fails, carry out three more tests. If all
three of these average values meet the requirement given in 5.2, the product meets the requirement for
fluidity. Otherwise it fails.
7.3 Setting time
7.3.1 Apparatus
7.3.1.1 Needle penetrometer, an example of which is shown in Figure 1, meeting the following
requirements:
a) Penetrometer needle (1), 50 mm long, of circular cross-section, with a diameter of (1,00 ± 0,05) mm
and a squared end.
b) Rod (2), of approximate dimensions 270 mm long and 10 mm in diameter.
c) Additional (compensating) weight (3).
d) The total mass of all the parts that move with the rod shall be (300 ± 1) g.
e) Scale (4), graduated in millimetres.
f) Base-plate (5) of plate glass, measuring about 100 mm × 100 mm.
4 © ISO 2013 – All rights reserved

---------------------- Page: 16 ----------------------

SIST EN ISO 6873:2013
ISO 6873:2013(E)

3
2
4
7
6
X
2
X
1 1
8
5
Key
1 Needle 5 Base plate
2 Rod 6 Stand
3 Additional (compensating) weight 7 Scale adjustment locking screw
4 Scale 8 Mould
Figure 1 — Example of needle penetrometer
7.3.1.2 Ring mould, constructed from a corrosion-resistant, non-absorbent material. There are two
alternatives.
7.3.1.2.1 Large conical mould, with an inside diameter of 70 mm at the top and 60 mm at the base, and
a height of 40 mm.
© ISO 2013 – All rights reserved 5

---------------------- Page: 17 ----------------------

SIST EN ISO 6873:2013
ISO 6873:2013(E)

7.3.1.2.2 Small cylindrical mould, with an inside diameter of 20 mm and height of 30 mm.
NOTE For effective utilization of resources, the smaller mould can be used in the place of the traditional larger
mould. The user will be aware that the decreased area allows fewer indentation sites [according to 7.3.2] and that
greater attention must be given to the time (relative to the anticipated setting time) of the first indentation.
7.3.1.3 Mould release agent, such as silicone spray or silicone grease.
7.3.2 Procedure
Coat the inside of the ring mould with a thin layer of mould release agent. Place the ring mould on the
base-plate, positioned to one side of the needle.
Mix the gypsum according to 6.3, using a mass of powder with the appropriate volume of water (ISO 3696,
Grade 3) that will produce a workable mix sufficient to fill the mould. Both powder and liquid should be
dispensed to an accuracy of 0,5 %.
NOTE 1 If the larger mould is used, add 400 g of the investment powder to the manufacturer’s recommended
quantity of water in a mixing bowl. If the smaller mould is used, add 100 g of the investment powder to the
manufacturer’s recommended quantity water in a mixing bowl.
The timer used during mixing is to continue running after mixing is completed and is the reference for
subsequent times.
Overfill the mould with the mix and then level the specimen surface to be flush with the top of the mould.
Raise the needle and move the mould to a position under the needle that is not less than 4 mm from the
mould wall. Lower the needle until it makes contact with the surface of the mix. Adjust the scale of the
penetrometer to read zero on its indicator and lock the scale in this position with the scale adjustment
locking screw. Hold the needle in contact with the surface of the specimen.
NOTE 2 For this design, the adjustable scale is attached to the rod and, once locked, moves (relative to the fixed
indicator) when the rod is raised or lowered. The zero locking position should allow an upward movement to
allow the needle to be withdrawn from the specimen and cleaned between readings, and a downward movement
for penetration into the specimen when readings are taken.
NOTE 3 An alternative design is possible and permitted if it produces the same relative movement between
scale and indicator to record the movement of the needle.
Beginning at a time between 1 min to 2 min prior to the anticipated setting time, which is the setting
time or mid-point of the setting time range given by the manufacturer in accordance with 8.2.1 h) [or
8.2.2 h), as appropriate for the packaging in which the product is supplied], release the rod gently and
record the release time as the first reading. Allow the needle to penetrate the specimen.
NOTE 4 For the smaller mould a maximum of 8 indentations is possible, for which the time between the first
and last readings is 1,75 min. The investigator should consider if this time span is adequate for the product under
test even when the minimum recommended starting time is used (i.e. 1 min before the anticipated setting time).
If this is in doubt, the larger mould is recommended.
NOTE 5 It is not necessary to wait for the needle to penetrate any further than 3 mm. Once this depth is reached,
the needle can be withdrawn in preparation to take the second reading.
Take the second and subsequent readings at (15 ± 1) s intervals as follows:
a) Raise the rod to withdraw the needle from the specimen. Move the mould to allow the next
penetration to be in a new area, which is at least 4 mm from the mould wall and from any other
penetration mark.
b) Wipe the needle clean and then bring its tip into contact with the specimen surface.
c) At the appropriate time, release the rod and record the release time (as the second reading, or after
that any subsequent reading). Allow the needle to penetrate the material for a time that will let steps
7.3.2 a) and b) for the next measurement to be completed in the 15 s period between measurements.
6 © ISO 2013 – All rights reserved

---------------------- Page: 18 ----------------------

SIST EN ISO 6873:2013
ISO 6873:2013(E)

NOTE 6 As for the first reading, when taking the second and subsequent readings it is not necessary to wait
for the needle to penetrate any further than 3 mm. Once this depth is reached, the needle can be withdrawn
in preparation for a subsequent reading.
d) Record the setting time as the total time from the start of mixing to the time when the needle first
fails to penetrate the specimen to a depth of 2 mm.
7.3.3 Evaluation
7.3.3.1 Type 1 products
Carry out the test twice. If both measurements meet both requirements given in 5.3, then the product
meets the requirement for setting time. If neither meets these requirements, then the product fails. If
one measurement meets the requirements given in 5.3, and the other fails, carry out three more tests. If
all three of these measurements meet the requirements given in 5.3, the product meets the requirement
for setting time. Otherwise, it fails.
7.3.3.2 Type 2, 3, 4 and 5 products
Carry out the test twice. If both measurements meet the requirement given in 5.3, then the product
meets the requirement for setting time. If neither meets the requirement, then the product fails. If one
measurement meets the requirement given in 5.3, and the other fails, carry out three more tests. If all
three of these measurements meet the requirement given in 5.3, the product meets the requirement for
setting time. Otherwise, it fails.
7.4 Linear setting expansion
7.4.1 Apparatus
7.4.1.1 Extensometer. There are two types. Either may be used.
7.4.1.1.1 Triangular cross-section trough, as shown in Figure 2, 3 and 4, made from a non-corroding
metallic material (such as aluminium, stainless steel or a brass alloy) and producing a specimen with
a length of (100,0 ± 0,1) mm. The apparatus is fitted with a device which measures change in length to
within 0,01 mm and exerts a measuring force which is no greater than 0,8 N. The internal cross-section
of the trough is an isosceles triangle having an angle of 90° with internal side lengths of (30 ± 1) mm. One
end of the trough is blocked with an immovable end-piece and the other with a movable end-piece having
a mass of (200 ± 10) g.
On the inside of this trough a horizontal line is scribed so as to define a t
...

SLOVENSKI STANDARD
oSIST prEN ISO 6873:2012
01-januar-2012
=RER]GUDYVWYR0DYþQLL]GHONL ,62',6
Dentistry - Gypsum products (ISO/DIS 6873:2011)
Zahnheilkunde - Gipse (ISO/DIS 6873:2011)
Médecine bucco-dentaire - Produits à base de gypse (ISO/DIS 6873:2011)
Ta slovenski standard je istoveten z: prEN ISO 6873
ICS:
11.060.10 =RERWHKQLþQLPDWHULDOL Dental materials
oSIST prEN ISO 6873:2012 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

---------------------- Page: 1 ----------------------
oSIST prEN ISO 6873:2012

---------------------- Page: 2 ----------------------
oSIST prEN ISO 6873:2012


EUROPEAN STANDARD
DRAFT
prEN ISO 6873
NORME EUROPÉENNE

EUROPÄISCHE NORM

November 2011
ICS 11.060.10 Will supersede EN ISO 6873:2000
English Version
Dentistry - Gypsum products (ISO/DIS 6873:2011)
Médecine bucco-dentaire - Produits à base de gypse Zahnheilkunde - Gipse (ISO/DIS 6873:2011)
(ISO/DIS 6873:2011)
This draft European Standard is submitted to CEN members for parallel enquiry. It has been drawn up by the Technical Committee
CEN/TC 55.

If this draft becomes a European Standard, CEN members are bound to comply with the CEN/CENELEC Internal Regulations which
stipulate the conditions for giving this European Standard the status of a national standard without any alteration.

This draft European Standard was established by CEN in three official versions (English, French, German). A version in any other language
made by translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management
Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland,
Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.

Recipients of this draft are invited to submit, with their comments, notification of any relevant patent rights of which they are aware and to
provide supporting documentation.

Warning : This document is not a European Standard. It is distributed for review and comments. It is subject to change without notice and
shall not be referred to as a European Standard.


EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2011 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN ISO 6873:2011: E
worldwide for CEN national Members.

---------------------- Page: 3 ----------------------
oSIST prEN ISO 6873:2012
prEN ISO 6873:2011 (E)
Contents Page
Foreword .3

2

---------------------- Page: 4 ----------------------
oSIST prEN ISO 6873:2012
prEN ISO 6873:2011 (E)
Foreword
This document (prEN ISO 6873:2011) has been prepared by Technical Committee ISO/TC 106 "Dentistry" in
collaboration with Technical Committee CEN/TC 55 “Dentistry” the secretariat of which is held by DIN.
This document is currently submitted to the parallel Enquiry.
This document will supersede EN ISO 6873:2000.
Endorsement notice
The text of ISO/DIS 6873:2011 has been approved by CEN as a prEN ISO 6873:2011 without any
modification.

3

---------------------- Page: 5 ----------------------
oSIST prEN ISO 6873:2012

---------------------- Page: 6 ----------------------
oSIST prEN ISO 6873:2012

DRAFT INTERNATIONAL STANDARD ISO/DIS 6873
ISO/TC 106/SC 2 Secretariat: ANSI
Voting begins on Voting terminates on

2011-11-17 2012-04-17
INTERNATIONAL ORGANIZATION FOR STANDARDIZATION  •  МЕЖДУНАРОДНАЯ ОРГАНИЗАЦИЯ ПО СТАНДАРТИЗАЦИИ  •  ORGANISATION INTERNATIONALE DE NORMALISATION


Dentistry — Gypsum products
Médecine bucco-dentaire — Produits à base de gypse
[Revision of first edition (ISO 6873:1998)]
ICS 11.060.10










ISO/CEN PARALLEL PROCESSING
This draft has been developed within the International Organization for Standardization (ISO), and
processed under the ISO-lead mode of collaboration as defined in the Vienna Agreement.
This draft is hereby submitted to the ISO member bodies and to the CEN member bodies for a parallel
five-month enquiry.
Should this draft be accepted, a final draft, established on the basis of comments received, will be
submitted to a parallel two-month approval vote in ISO and formal vote in CEN.

To expedite distribution, this document is circulated as received from the committee
secretariat. ISO Central Secretariat work of editing and text composition will be undertaken at
publication stage.
Pour accélérer la distribution, le présent document est distribué tel qu'il est parvenu du
secrétariat du comité. Le travail de rédaction et de composition de texte sera effectué au
Secrétariat central de l'ISO au stade de publication.



THIS DOCUMENT IS A DRAFT CIRCULATED FOR COMMENT AND APPROVAL. IT IS THEREFORE SUBJECT TO CHANGE AND MAY NOT BE
REFERRED TO AS AN INTERNATIONAL STANDARD UNTIL PUBLISHED AS SUCH.
IN ADDITION TO THEIR EVALUATION AS BEING ACCEPTABLE FOR INDUSTRIAL, TECHNOLOGICAL, COMMERCIAL AND USER PURPOSES, DRAFT
INTERNATIONAL STANDARDS MAY ON OCCASION HAVE TO BE CONSIDERED IN THE LIGHT OF THEIR POTENTIAL TO BECOME STANDARDS TO
WHICH REFERENCE MAY BE MADE IN NATIONAL REGULATIONS.
RECIPIENTS OF THIS DRAFT ARE INVITED TO SUBMIT, WITH THEIR COMMENTS, NOTIFICATION OF ANY RELEVANT PATENT RIGHTS OF WHICH
THEY ARE AWARE AND TO PROVIDE SUPPORTING DOCUMENTATION.
©  International Organization for Standardization, 2011

---------------------- Page: 7 ----------------------
oSIST prEN ISO 6873:2012
ISO/DIS 6873

Copyright notice
This ISO document is a Draft International Standard and is copyright-protected by ISO. Except as permitted
under the applicable laws of the user’s country, neither this ISO draft nor any extract from it may be
reproduced, stored in a retrieval system or transmitted in any form or by any means, electronic,
photocopying, recording or otherwise, without prior written permission being secured.
Requests for permission to reproduce should be addressed to either ISO at the address below or ISO’s
member body in the country of the requester.
ISO copyright office
Case postale 56 • CH-1211 Geneva 20
Tel. + 41 22 749 01 11
Fax + 41 22 749 09 47
E-mail copyright@iso.org
Web www.iso.org
Reproduction may be subject to royalty payments or a licensing agreement.
Violators may be prosecuted.

ii © ISO 2011 – All rights reserved

---------------------- Page: 8 ----------------------
oSIST prEN ISO 6873:2012
ISO/DIS 6873
Contents Page
Foreword . iv
Introduction . v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Classification . 1
5 Requirements . 2
5.1 Quality. 2
5.2 Fluidity at pouring time (Type 1 materials only) . 2
5.3 Setting time . 2
5.4 Linear setting expansion . 2
5.5 Fracture (Type 1 materials only) . 3
5.6 Compressive strength. 3
5.7 Reproduction of detail . 3
6 Testing - general . 3
6.1 Sampling . 3
6.2 Test conditions . 3
6.3 Mixing methods . 3
7 Test methods . 3
7.1 Visual inspection . 3
7.2 Fluidity at pouring time for Type 1 materials . 4
7.3 Setting time . 4
7.4 Linear setting expansion . 5
7.5 Fracture . 7
7.6 Compressive strength. 8
7.7 Reproduction of detail . 8
8 Packaging, marking and information to be supplied by the manufacturer . 10
8.1 Packaging . 10
8.2 Labelling . 10
8.3 Information to be supplied by the manufacturer . 11





© ISO 2002 – All rights reserved iii

DRAFT 2011

---------------------- Page: 9 ----------------------
oSIST prEN ISO 6873:2012
ISO/DIS 6873
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies
(ISO member bodies). The work of preparing International Standards is normally carried out through ISO
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. ISO collaborates closely with the
International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. 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.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. ISO shall not be held responsible for identifying any or all such patent rights.
Specific qualitative and quantitative requirements for freedom from biological hazard are not included in this
International Standard but it is recommended that, in assessing possible biological hazards, reference should
be made to ISO 10993-1 and ISO 7405.
ISO 6873 was prepared by Technical Committee ISO/TC 106, Dentistry, Subcommittee SC 2, Prosthodontic
materials.
This third edition cancels and replaces the second edition (ISO 6873:1998) of which Clause 4 Classification,
Comment [C1]: “and designation” deleted
Clause 5.4 Setting expansion requirements and Clause 8.2, Labelling have been technically revised. An
Comment [C2]: addition
alternative design for the extensometer used to measure setting expansion is included
iv © ISO 2002 – All rights reserved

DRAFT 2011

---------------------- Page: 10 ----------------------
oSIST prEN ISO 6873:2012
ISO/DIS 6873
Comment [C3]: addition of an Introduction
Introduction
This revision was necessary since gypsum products have been marketed since the last edition of ISO 6873
was published, which have properties (required for newly introduced dental technology) for which the
requirements set in that edition were not appropriate. In this edition the classification has been altered to take
this into account and in so doing, requirements have been set appropriately. In addition there was concern
that Type 4 dental stone used for CAD CAM models should not produce significant setting expansion at times
beyond the 2 hour period at which setting expansion was measured and a requirement had been set. In this
edition the setting expansion for Type 4 dental stone is measured at 24 hours as well.

© ISO 2002 – All rights reserved v

DRAFT 2011

---------------------- Page: 11 ----------------------
oSIST prEN ISO 6873:2012

---------------------- Page: 12 ----------------------
oSIST prEN ISO 6873:2012
DRAFT INTERNATIONAL STANDARD ISO/DIS 6873

Error! Reference source not found.
1 Scope
This International Standard gives a classification of, and specifies requirements for, gypsum products used for
dental purposes such as making oral impressions, moulds, casts, dies or model bases, and mounting models.
It specifies the test methods to be employed to determine compliance with these requirements. It also includes
requirements for the labelling of packaging and for adequate instructions to accompany each package.
This International Standard does not apply to dental bone graft substitutes composed of calcium sulphate
hemihydrate (or gypsum).
2 Normative references
The following referenced documents are indispensable for the application 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 1302, Geometrical product specifications (GPS) – indication of surface texture in technical product
Comment [C4]: corrected to normal upright
text
documentation
ISO 1942, Dentistry — Vocabulary
ISO 3696, 1987: Water for analytical laboratory use — Specification and test methods
ISO 8601, Data elements of interchange formats – Information interchange – Representation of dates and
times
ISO 15223-1 Medical devices – Symbols to be used with medical device labels, labelling and information
supplied – Part 1: General requirements

3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 1942 and the following apply.
3.1
gypsum product
dental product composed essentially of a hemihydrate of calcium sulfate and any necessary modifiers.
NOTE Colouring matter and flavouring, if present, are regarded as necessary modifiers.
Comment [C5]: “and designation” deleted
4 Classification
The five types of gypsum product used in dentistry are classified in accordance with this International
Standard as follows:
© ISO 2002 – All rights reserved 1

DRAFT 2011

---------------------- Page: 13 ----------------------
oSIST prEN ISO 6873:2012
ISO/DIS 6873
Type 1:  Dental plaster for impressions
Type 2:  Dental plaster for mounting (Class 1) and for models (Class 2)
Type 3:  Dental stone for models
Type 4:  Dental stone (high strength, low expansion) for dies, model bases and CAD/CAM dies
Type 5: Dental stone (high strength, high expansion) for dies when this degree of expansion is necessary for
shrinkage compensation of some materials used in dental restoration.
5 Requirements
5.1 Quality
When tested according to 7.1, the powder shall be uniform and free from foreign matter and lumps. When
mixed according to the manufacturer's instructions the product shall produce a homogeneous mix. Comment [C6]: “smooth” deleted
5.2 Fluidity at pouring time (Type 1 materials only)
When tested according to 7.2 at a pouring time of 1,25 min, the fluidity of type 1 materials shall be equal to or
greater than 70 mm.
5.3 Setting time
When tested according to 7.3, the setting time of type 1 materials shall be in the range of 2,5 min to 5,0 min
and the setting time of all material types shall be within 20 % of the value claimed by the manufacturer in 8.3
c). If the manufacturer claims a range of setting time, then the midpoint of this range is taken as the value
claimed by the manufacturer.
5.4 Linear setting expansion
When tested according to 7.4, the setting expansion shall be within the range listed in Table 1.
Comment [C7]: 1) Title added to table 2) table
Table 1 – Strength and thermal expansion requirements
formatted correctly 3) Spaces added between the number
and h eg 2 h
Setting expansion Compressive strength
Type MPa
%
1 h
2 h 24 h
min. max. min. max. min. max.
1 0,00 0,15 - - 4,0 8,0
2 (Class1) 0,00 0,05 - - 9,0 -
2 (Class 2) 0,00 0,30 - - 9,0 -
3 0,00 0,20 - - 20,0 -
4 0,00 0,15 0,00 0,18 35,0 -
5 0,16 0,30 - - 35,0 -

2 © ISO 2002 – All rights reserved

DRAFT 2011

---------------------- Page: 14 ----------------------
oSIST prEN ISO 6873:2012
ISO/DIS 6873
5.5 Fracture (Type 1 materials only)
When tested according to 7.5, Type 1 impression plaster shall break with a clean fracture and be readily
reassembled to form the shape and size of the original unbroken specimen.
5.6 Compressive strength
When tested according to 7.6, the compressive strength shall meet the requirement(s) of Table 1.
Comment [C8]: Brackets added around “s”
5.7 Reproduction of detail
Types 1 and 2 when tested according to 7.7, line (c) in Figure 6 shall be reproduced.
Types 3, 4 and 5 when tested according to 7.7, line (a) in Figure 6 shall be reproduced.
6 Testing - general
6.1 Sampling
Select the material for testing from one lot that is not beyond its expiry date [8.2.1 g)]. Do not use powder from
previously opened, broken or damaged containers.
6.2 Test conditions
Carry out all mixing and testing of the dental gypsum product at (23 ± 2) °C and (50 ± 10) % relative humidity.
Ensure that all apparatus and instruments used in mixing and testing are clean, dry and free from particles of
gypsum. Before testing begins, hold material and test apparatus at the test temperature for a period of time
that is sufficient to equilibrate with this temperature.
Note: A minimum storage period of 15 h is recommended.
6.3 Mixing method
Mix by one of the methods (hand or mechanical) specified by the manufacturer in the instructions [8.3 b)],
using water, which meets the requirements of ISO 3696, Grade 3.
7 Test methods
7.1 Visual inspection
Carry out visual inspection without magnification to determine compliance with the requirements given in 5.1,
5.5 and 5.7 (unless as stated otherwise, as in 7.7).
Comment [C9]: NB
I have deleted “by visual inspection” after 5.7
now since this repeats text at the start of the
Determine compliance with the requirements given in 8 for packaging, marking and information supplied by
sentence. This is a correction to the DIS texts
the manufacturer.
in both the earlier & the later documents
© ISO 2002 – All rights reserved 3

DRAFT 2011

---------------------- Page: 15 ----------------------
oSIST prEN ISO 6873:2012
ISO/DIS 6873
7.2 Fluidity at pouring time for Type 1 materials
7.2.1 Apparatus
Comment [C10]: Formatted correctly (according to
7.2.1.1 Cylindrical mould,
template instructions) here and at all other level 3 sub-
clauses. Ie text stated on new line.
constructed from a corrosion-resistant, non-absorbent material, having a length of (50,0 ± 0,1) mm and an
inside diameter of (35,0 ± 0,1) mm. Clean and dry.
Comment [C11]: Text content the same but reordered
to be more logical
7.2.1.2 Glass plate,
flat and smooth, with sides of length at least 100 mm. Clean and dry.
Comment [C12]: As for 7.2.1.1, text content the same
but reordered
Comment [C13]: Added text
7.2.1.3 Means of measuring lengths from 35 mm to in excess of 70 mm,
to measure the major and minor diameters of the slumped mix to the nearest millimetre.
Comment [C14]: Text in 7.2.2 separated into 3
7.2.2 Procedure
paragraphs. (Was a single paragraph)
Rest the glass plate (7.2.1.2) on a surface that is free of vibration. Place the mould (7.2.1.1) upright on the
centre of the plate.
Add (100 ± 0,1) g of the sample to the manufacturer’s recommended quantity of water (ISO 3696, Grade 3) in
Comment [C15]: Addition: the water quality
a mixing bowl and mix as described in 6.3.
Comment [C16]: NB I have changed “to” to “in”. It is a
correction to both the earlier & later drafts
Completely fill the mould and level off the mixed material so that it is flush with the top of the mould. At 1,25
Comment [C17]: Addition
min after the start of mixing, lift the mould vertically from the plate at a rate of approximately 10 mm/s and
allow the mix to slump or spread over the plate. One minute after the mould is lifted, measure the major and
minor axes of the slumped material to the nearest millimetre. Record the average of these two diameters as
the fluidity at the pouring time.
7.2.3 Evaluation
Carry out the test twice. If both average values meet the requirements for fluidity in 5.2, then the product Comment [C18]: “two times” changed to “twice”
meets the requirement for fluidity. If neither meets the requirement, then the product fails to meet the
requirement. If one average value meets the requirement for fluidity and the other fails, carry out three more
Comment [C19]: “(5.2)” deleted after fluidity
tests. If all three of these average values meet the requirement for fluidity, then the product meets the
Comment [C20]: As C19
requirement for fluidity. Otherwise it fails.
7.3 Setting time
7.3.1 Apparatus
7.3.1.1 Needle penetrometer apparatus,
an example of which is shown in Figure 1, meeting the following requirements:
a) Penetrometer needle (1), 50 mm long, of circular cross-section and with a diameter of (1 ± 0,05) mm. Comment [C21]: (A) changed to (1)
b) Rod (2), of approximate dimensions 270 mm long and 10 mm in diameter. Comment [C22]: (B) changed to (2)
c) Additional (compensating) weight (3). Comment [C23]: ( C) changed to (3)
d) Total mass of the needle, rod, and additional weight (1, 2, and 3) shall be (300 ± 1) g. Comment [C24]: (A, B and C) changed to (1, 2 and 3)
e) Scale (4), graduated in millimetres.
Comment [C25]: (D) changed to (4)
4 © ISO 2002 – All rights reserved

DRAFT 2011

---------------------- Page: 16 ----------------------
oSIST prEN ISO 6873:2012
ISO/DIS 6873
f) Base-plate (5) of plate glass, measuring about 100 mm × 100 mm.
Comment [C26]: (E) changed to (5)
Comment [C27]: Revised heading
7.3.1.2 Ring mould,
constructed from a corrosion-resistant, non-absorbent material. Either of the two mould types listed here may
be used.
Comment [C28]: New text. “with an inside
diameter of 70 mm at the top and 60 mm at the
base, and a height of 40 mm. with an inside
7.3.1.2.1 Large conical
diameter of 70 mm at the top and 60 mm at the
base, and a height of 40 mm (G) deleted.
with an inside diameter of 70 mm at the top and 60 mm at the base, and a height of 40 mm.
Comment [C29]: New sub-clauses. Two
mould are now allowed
7.3.1.2.2 Small cylindrical
with an inside diameter of 20 mm and height of 30 mm.
Note: For effective utilisation of resources, the smaller mould may be used in the place of the traditional mould larger
mould. The user will be aware that the decreased area allows fewer indentation sites [according to 7.3.2 a)] and that
greater attention must be given to the time (relative to the anticipated setting time) of the first indentation.
7.3.2 Procedure
If the larger mould is used, add 400 g of the sample to the manufacturer's recommended quantity of water Comment [C30]: New text
(ISO 3696, Grade 3) in a mixing bowl. If the smaller mould is used, add 100g of the sample to the
Comment [C31]: Text replaces “distilled
manufacturer's recommended quantity of water (ISO 3696, Grade 3). Mix as described in 6.3. Place the
water”
mould (7.3.1.2) on the base-plate [7.3.1.1 f)] and fill completely then level the specimen flush with the top of
Comment [C32]: Added text
the mould. Using the needle penetrometer apparatus (7.3.1.1) and beginning 1 min or 2 min prior to the
Comment [C33]: New text
anticipated setting time (usually at the loss of gloss or excess water), allow the needle to penetrate the mix at
(15 1) s intervals as follows.
Comment [C34]: Now a separate sentence
Comment [C35]: New text
a) Move the mould to allow the next penetration to be in a new area, which is at least 5 mm from the mould
Comment [C36]: Change “Vicat needle” to
wall and from any other penetration mark.
“needle penetrometer”
b) Wipe the needle clean and then bring its tip into contact with the surface of the mix and lock the rod in
position with the lock screw.
c) Read the scale and, at the appropriate time, release the rod. [Allow the needle to penetrate the material
for a time that will let steps 7.3.2 a) and b) for the next measurement to be completed in the 15s period
between measurements]. Note the new position of the scale and calculate the depth of penetration.
Comment [C37]: New text
d) Record the setting time as the total time from the start of mixing to the time when the needle first fails to
penetrate the specimen to a depth of at least 2 mm.
7.3.3 Evaluation
Carry out the test twice. If both measurements meet the requirement for setting time (5.3), then the product Comment [C38]: “twice” replaces “two times”
meets the requirement for setting time. If neither meets the requirement for setting time, then the product fails
to meet the requirements for setting time. If one measurement meets the requirement for setting time and the
other fails, carry out three more tests. If all three of these measurements meet the requirement for setting
time, then the product meets the requirement for setting time. Otherwise the product fails.
7.4 Linear setting expansion
7.4.1 Apparatus
7.4.1.1 Extensometer:
There are two types. Either may be used. Comment [C39]: New text
© ISO 2002 – All rights reserved 5

DRAFT 2011

---------------------- Page: 17 ----------------------
oSIST prEN ISO 6873:2012
ISO/DIS 6873
7.4.1.1.1 Triangular cross-section trough
as shown in Figure 2, 3 and 4, made from a non-corroding metallic material (such as aluminium or brass alloy)
and producing a specimen with a length of (100 0,1) mm. The apparatus is fitted with a device which
measures change in length to within 0,01 mm and exerts a measuring force which is no greater than 0,8 N.
The internal cross-section of the trough is an isosceles triangle having an angle of 90° with internal side
lengths of (30 1) mm. One end of the trough is blocked with an immovable end-piece and the other with a
movable end-piece having a mass of (200 10) g.
On the inside of this trough a horizontal line is scribed so as to define a triangle with included sides of length
(25 1) mm.
7.4.1.1.2 Square cross-section trough
as shown in Figure 5, made from a non-corroding metallic material (such as aluminium or brass alloy) and
producing a specimen with a length, a = (100 ± 0,1) mm. The apparatus is fitted with a device which measures
a change in length to within 0,01 mm and exerts a measuring force which is no greater than 0,8 N. The
internal cross-section of the trough is square having a depth and width, b = c = (20 ± 0,1) mm. One end of the
trough is blocked with an immovable end-piece and the other with a movable end-piece having a mass of (35
± 0,5) g.
Comment [C40]: 7.4.1.1.1 & 7.4.1.1.2 are new sub-
clauses
7.4.1.2 Polytetrafluoroethylene (PTFE) sheet
0,1 mm to 0,2 mm thick
7.4.1.3 Mould-release agent.
7.4.1.4 Length measuring instrument,
that is capable of a measurement up to 105 mm to an accuracy of 0,01 mm (such as a travelling microscope,
Vernier calliper or micrometer
...

Questions, Comments and Discussion

Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.