EN ISO 15912:2016

SLOVENSKI STANDARD
01-maj-2016
1DGRPHãþD
SIST EN ISO 15912:2006
SIST EN ISO 15912:2006/A1:2011
Zobozdravstvo - Polnila in refrakcijski materiali (ISO 15912:2016)
Dentistry - Refractory investment and die material (ISO 15912:2016)
Zahnheilkunde - Hochtemperaturbeständige Einbettmassen und Stumpfmaterialien (ISO
15912:2016)
Art dentaire - Revêtements et matériaux pour modèles réfractaires (ISO 15912:2016)
Ta slovenski standard je istoveten z: EN ISO 15912:2016
ICS:
11.060.10 =RERWHKQLþQLPDWHULDOL Dental materials
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN ISO 15912
EUROPEAN STANDARD
NORME EUROPÉENNE
February 2016
EUROPÄISCHE NORM
ICS 11.060.10 Supersedes EN ISO 15912:2006
English Version
Dentistry - Refractory investment and die material (ISO
15912:2016)
Médecine bucco-dentaire - Revêtements et matériaux Zahnheilkunde - Hochtemperaturbeständige
pour modèles réfractaires (ISO 15912:2016) Einbettmassen und Stumpfmaterialien (ISO
15912:2016)
This European Standard was approved by CEN on 24 October 2015.

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

CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2016 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 15912:2016 E
worldwide for CEN national Members.

Contents Page
European foreword . 3
European foreword
This document (EN ISO 15912:2016) 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 August 2016, and conflicting national standards shall
be withdrawn at the latest by August 2016.
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 15912:2006.
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 15912:2016 has been approved by CEN as EN ISO 15912:2016 without any modification.

INTERNATIONAL ISO
STANDARD 15912
Second edition
2016-01-15
Dentistry — Refractory investment
and die material
Médecine bucco-dentaire — Revêtements et matériaux pour
modèles réfractaires
Reference number
ISO 15912:2016(E)
©
ISO 2016
ISO 15912:2016(E)
© ISO 2016, Published in Switzerland
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
Ch. de Blandonnet 8 • CP 401
CH-1214 Vernier, Geneva, Switzerland
Tel. +41 22 749 01 11
Fax +41 22 749 09 47
copyright@iso.org
www.iso.org
ii © ISO 2016 – All rights reserved

ISO 15912:2016(E)
Contents Page
Foreword .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Classification . 3
5 Requirements . 3
5.1 General . 3
5.2 Material consistency and freedom from contamination . 3
5.3 Fluidity . 3
5.4 Initial setting time . 4
5.5 Compressive strength . 4
5.6 Linear thermal dimensional change . 4
5.7 Adequacy of expansion of Type 1 and Type 2 materials . 4
6 Sampling, test conditions and mixing . 4
6.1 Sampling . 4
6.2 Test conditions . 4
6.3 Mixing . 5
6.3.1 Apparatus . 5
6.3.2 Procedure . 5
7 Test methods . 5
7.1 Material consistency and freedom from contamination . 5
7.1.1 Test procedure . 5
7.1.2 Test report . 5
7.2 Fluidity . 5
7.2.1 Apparatus . 5
7.2.2 Number of test-pieces . 6
7.2.3 Test procedure . 6
7.2.4 Evaluation of results . 6
7.2.5 Test report . 6
7.3 Initial setting time . 7
7.3.1 Apparatus . 7
7.3.2 Procedure . 9
7.3.3 Number of determinations. 9
7.3.4 Evaluation of results .10
7.3.5 Test report .10
7.4 Compressive strength .10
7.4.1 Apparatus .10
7.4.2 Number of test-pieces .10
7.4.3 Preparation of test-pieces .11
7.4.4 Test procedure .11
7.4.5 Evaluation of results .12
7.4.6 Test report .12
7.5 Linear thermal dimensional change .12
7.5.1 Apparatus .12
7.5.2 Number of test-pieces .13
7.5.3 Preparation of the test-piece .13
7.5.4 Test procedure for the measurement of linear thermal expansion of Types
1, 2 and 3 products . .14
7.5.5 Test procedure for the measurement of linear thermal dimensional
changes of a Type 4 product .15
7.5.6 Evaluation of results .15
7.5.7 Test report .16
ISO 15912:2016(E)
7.6 Adequacy of expansion of Type 1 and Type 2 products .16
7.6.1 General.16
7.6.2 Type 1 and Type 2 products intended for casting of dental metallic materials .17
7.6.3 Type 1 products intended for dental pressable-ceramic products .18
7.6.4 Evaluation of results .20
7.6.5 Test report .20
8 Manufacturer’s instructions .20
8.1 General .20
8.2 Information for use .20
8.3 Physical properties .21
8.4 Safety labelling and instructions for a product containing silica .22
9 Marking .22
9.1 General .22
9.2 Powder container .22
9.2.1 Outer container .22
9.2.2 Individual packets .23
9.3 Liquid container .23
10 Packaging .23
10.1 Powder .23
10.2 Liquid .24
Bibliography .25
iv © ISO 2016 – All rights reserved

ISO 15912:2016(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.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).
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. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www.iso.org/patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation on the meaning of ISO specific terms and expressions related to conformity
assessment, as well as information about ISO’s adherence to the WTO principles in the Technical
Barriers to Trade (TBT) see the following URL: Foreword - Supplementary information
The committee responsible for this document is ISO/TC 106 Dentistry, Subcommittee SC2,
Prosthodontic Materials.
This second edition cancels and replaces the first edition (ISO 15912:2006), which has been technically
revised. It also incorporates the Amendment ISO 15912-1:2006/Amd 1:2011.
In this edition, dental pressable-ceramic investment materials are included in the Scope for the first
time. These products are intended for the production of ceramic crowns and inlays and, as such, the
same requirements as those for an investment product intended for the production of metallic crowns
and inlays by casting are relevant (Type 1, according to the classification in this standard).
The previous edition contained requirements and test methods that had been developed for
discontinued composition specific standards. In recent years products have been introduced that
have other chemistries (for the binder and the refractory phase), specifically to minimize chemical
reaction between the mould and the molten casting metallic material. A number of technical changes
have been made to enable all dental casting investment products, regardless of their composition,
to seek compliance with this International Standard and maintains the agreed philosophy that this
International Standard should be inclusive, application-driven and not be limited by composition
considerations.
Where appropriate, aspects of the test procedures have been changed to follow the manufacturer’s
instructions for use. The requirement for thermal dimensional change now takes into account the
cooling of some products (after burn-out) to a lower casting temperature. The specification for the
dilatometer has been changed for it to be compatible with the heating — and where relevant, the
cooling after burn-out — of the product to the casting temperature.
The procedure for determining the initial setting time has been revised to harmonize with that
[1]
present in the latest edition of the standard for dental gypsum products, ISO 6873:2013. Although
substantially editorial, there are technical changes.
Information for use now requires a statement of the type of refractory phase(s) that is (are) present.
ISO 15912:2016(E)
Labelling requirements for products that contain silica have been revised to comply with the current
[2]
United Nations Globally Harmonized System for Classification and Labelling of Chemicals (UN GHS)
and recommendations for silica as a hazardous material.
Containers of liquid must be marked to indicate the use to which the liquid is put.
vi © ISO 2016 – All rights reserved

INTERNATIONAL STANDARD ISO 15912:2016(E)
Dentistry — Refractory investment and die material
1 Scope
This International Standard gives requirements and test methods for determining the compliance of
dental casting investment, dental brazing investment, dental pressable-ceramic investment and dental
refractory die materials used in the dental laboratory, regardless of the composition of the refractory
powder, the composition of the binder, or the particular application.
This International Standard classifies such products into types and classes, according to their intended
use and the burn-out procedure recommended by the manufacturer.
It also gives requirements for marking, labelling and manufacturer’s instructions.
It specifies requirements for the essential physical and mechanical properties of the products and the
test methods to be used for determining them.
NOTE 1 Compliance with all of the requirements presented in Clause 5 may not be necessary for some products,
and a requirement might not be applicable to a product with a particular binder chemistry or be intended for an
application in which that requirement is irrelevant. When this is the case, a clear statement to this effect is given
according to Clause 5.
NOTE 2 A specific quantitative requirement for setting expansion is not included in this International Standard.
[1]
If the setting expansion of gypsum-bonded investment is measured, then the procedure given in ISO 6873 can
be considered — a procedure not recommended, however, for investment materials with other binders.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated
references, the latest edition of the referenced document (including any amendments) applies.
ISO 286-2, Geometrical product specifications (GPS) — ISO code system for tolerances on linear sizes —
Part 2: Tables of standard tolerance classes and limit deviations for holes and shafts
ISO 1942, Dentistry — Vocabulary
ISO 3696, Water for analytical laboratory use — Specification and test methods
ISO 6344-1, Coated abrasives — Grain size analysis — Part 1: Grain size distribution test
ISO 6872, Dentistry — Ceramic materials
ISO 8601, Data elements and interchange formats — Information interchange — Representation of
dates and times
ISO 15854, Dentistry — Casting and baseplate waxes
ISO 22674, Dentistry — Metallic materials for fixed and removable restorations and appliances
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 1942 and the following apply.
ISO 15912:2016(E)
3.1
dental casting investment material
powdered particulate refractory and binder system that is mixed with a specified liquid to produce a
pourable fluid that sets around a pattern to form the mould for casting a dental metallic prosthesis
Note 1 to entry: In some products, the binder may be dispersed in the refractory powder and the product is supplied
as a mixed powder. Alternatively, the chemistry of the binder may lead to it being present in a solution (to be used
with the powder that is supplied) with part or none of it being dispersed in the refractory powder, as received.
Note 2 to entry: The specified liquid may be pure water, an aqueous binder solution, or an aqueous solution to
enhance expansion.
3.2
dental refractory die material
powdered particulate refractory and binder system that is mixed with a specified liquid to produce a
fluid that sets (and is designed specifically) to form of a hard die, suitable for the production of a dental
ceramic prosthesis using the sintering technique
3.3
dental brazing investment material
powdered particulate refractory and binder system that is mixed with a specified liquid to produce a
fluid that sets (and is designed specifically) to form a cast upon which metallic components are held, or
are partly embedded, accurately in place while they are joined by brazing
Note 1 to entry: The cast may be referred to as the model, though that is a deprecated term.
3.4
dental pressable ceramic investment
powdered particulate refractory and binder system that is mixed with a specified liquid to produce
a pourable fluid that sets around a pattern to form a mould into which a dental pressable-ceramic,
softened by heating, can be forced under pressure
3.5
special liquid
liquid, other than water, supplied by the manufacturer for mixing with the dental casting investment
powder for the purpose of increasing the expansion of the mould
3.6
slow- or step-heating method
heating method in which (at a time after setting that is recommended by the manufacturer) the
dental casting investment mould, or dental pressable-ceramic mould, or dental brazing investment
cast or dental refractory die is placed in a burn-out furnace set at room temperature, after which
the temperature of the furnace is increased to the end temperature in a series of stages and at a
programmed rate recommended by the manufacturer
3.7
quick-heating method
heating method in which (at a time after setting that is recommended by the manufacturer) the dental
casting investment mould, or dental pressable-ceramic mould, or dental brazing investment cast, or
dental refractory die is placed directly into the hot burn-out furnace that is set and held at the burn-out
temperature recommended by the manufacturer
3.8
burn-out temperature
temperature to which the mould is heated to burn off the pattern material
and expand the mould
3.9
burn-out temperature
temperature to which the cast is heated to burn off any material used for shielding
and accurately locating the components to be brazed, and to expand the cast
2 © ISO 2016 – All rights reserved

ISO 15912:2016(E)
3.10
burn-out temperature
temperature to which the die is heated initially to burn off the pattern material
3.11
casting temperature
temperature of the mould at
which the molten metallic material is forced into the mould
3.12
ceramic pressing temperature
temperature at which
the mould and ceramic ingot are taken and at which the ceramic is pressed into the mould
Note 1 to entry: The mould is placed in a burn-out furnace at a lower temperature and held at this temperature
before the pressable-ceramic ingot is placed in the crucible of the mould, after which both are transferred to the
pressing furnace, that is at, or is raised to, a higher temperature to soften the ceramic ingot
3.13
green state
condition of the material immediately after setting before structural changes are brought about by
aging or burn-out, changes that produce increased strength or further dimensional changes
4 Classification
For the purposes of this International Standard, dental casting investment, dental brazing investment,
dental pressable-ceramic investment and dental refractory die materials are classified into the
following types, according to the intended application:
— Type 1, for the construction of inlays, crowns and other fixed prostheses;
— Type 2, for the construction of complete or partial dentures or other removable appliances;
— Type 3, for the construction of casts used in brazing procedures;
— Type 4, for the construction of refractory dies.
In addition, the materials are divided into two classes: Class 1 is recommended for burn-out by a slow-
or step-heating method; Class 2 is recommended for burn-out by a quick-heating method.
5 Requirements
5.1 General
If a manufacturer claims suitability for both classes, then the material shall satisfy the requirements
when it is subjected to both heating techniques. This applies to requirements 5.5 and 5.6 and, if
appropriate, requirement 5.7.
5.2 Material consistency and freedom from contamination
When examined in accordance with 7.1, the powder shall be uniform and free of lumps and foreign
matter. If a special liquid is supplied, it shall be free of sediment.
5.3 Fluidity
When measured in accordance with 7.2, the fluidity shall not vary by more than 30 % from the value
stated by the manufacturer [according to 8.3 a)].
ISO 15912:2016(E)
This requirement does not apply to silica bonded investments (i.e. products in which an alcoholic
solution of ethyl silicate is used in the binding system).
5.4 Initial setting time
When measured in accordance with 7.3, the initial setting time shall not vary by more than 30 % from
the value stated by the manufacturer [according to 8.3 b)]. If the manufacturer gives a range for the
initial setting time, then the measured initial setting time shall not vary by more than 30 % from the
mid-point of this range.
5.5 Compressive strength
When measured in accordance with 7.4, the compressive strength of a test-piece shall not be less than
70 % of the value stated by the manufacturer [according to 8.3 c)] and in no case shall be lower than 2 MPa.
5.6 Linear thermal dimensional change
When measured in accordance with 7.5, the linear thermal expansion, for all four Types, shall not vary
by more than 20 % from the value stated by the manufacturer [according to 8.3 d)]. If the manufacturer
gives a range for the linear thermal expansion, then the measured linear thermal expansion shall not
vary by more than 20 % from the mid-point of this range.
When measured in accordance with 7.5, the linear firing shrinkage for a Type 4 material shall not vary
by more than 15 % from the value stated by the manufacturer [according to 8.3 e)]. If the manufacturer
gives a range for the linear firing shrinkage, then the measured linear firing shrinkage shall not vary by
more than 15 % from the mid-point of this range.
5.7 Adequacy of expansion of Type 1 and Type 2 materials
When cast in accordance with 7.6, the diameter of the cast metallic disc, or when pressed in accordance
with 7.6, the diameter of the pressed ceramic disc (as is appropriate) with respect to the diameter of the
pattern from which it was made, shall be
a) no smaller than 99,5 % in case of a Type 1 material;
b) no smaller than 99,0 % in case of a Type 2 material.
This does not apply to either dental brazing investment material, Type 3, or dental refractory die
material, Type 4.
6 Sampling, test conditions and mixing
6.1 Sampling
Use material from a single lot in packages that have been produced for retail. Use only sealed,
undamaged packages (i.e. packets and containers) that have not exceeded the “use before” date.
6.2 Test conditions
Carry out all testing in a controlled atmosphere: (23 ± 2) °C, (50 ± 10) % relative humidity and free
from obvious draughts.
Holding the material and all test equipment under these controlled conditions for a minimum period of
15 h prior to testing is recommended.
4 © ISO 2016 – All rights reserved

ISO 15912:2016(E)
6.3 Mixing
Mix according to the manufacturer’s instructions. When a special liquid is supplied, use it at the
manufacturer’s recommended dilution according to 8.2 d). If water is required, use water that complies
with Grade 3 according to ISO 3696.
If a range is given in 8.2 e) for the powder to liquid ratio, or in 8.2 d) for the dilution of the special
liquid, use the midpoint of this range to produce a mix for determining compliance with requirements
5.3, 5.4, 5.5 and 5.6.
6.3.1 Apparatus
The following items may be needed, depending on the manufacturer’s instructions:
a) mixing bowl, clean, dry, flexible, for hand mixing;
b) spatula, rigid for hand mixing;
c) vacuum mixer with an appropriate clean and dry mixing bowl;
d) timer, capable of measuring time to an accuracy of 1 s.
6.3.2 Procedure
Measure the required mass of powder and the recommended volume of liquid, each to an accuracy of 1 %.
Pour the liquid into the mixing bowl and add the powder. Commence timing when liquid and powder
make first contact.
Hand spatulate and/or mix mechanically (with a vacuum, if specified) for the appropriate period,
according to manufacturer’s instructions. If the manufacturer recommends a range of mixing times,
use the mid-point of the range.
7 Test methods
7.1 Material consistency and freedom from contamination
7.1.1 Test procedure
Examine the material, as received, visually without the aid of magnification. Use eyesight that has
nominally normal visual acuity. Corrective (non-magnifying) lenses may be worn.
7.1.2 Test report
Report whether the product meets, or does not meet, the requirement for material consistency and
freedom from contamination (5.2). If it does not meet this requirement, state the reason.
7.2 Fluidity
7.2.1 Apparatus
7.2.1.1 Clean and dry cylindrical ring mould, having a length (50 ± 1) mm, an inside diameter of
(35 ± 1) mm that is made from a corrosion-resistant, non-absorbent material.
7.2.1.2 Flat square glass plate, with a glazed surface and measuring at least 150 mm × 150 mm.
ISO 15912:2016(E)
7.2.1.3 Dental vibrator.
7.2.1.4 Scale or ruler, graduated in millimetres and at least 150 mm in length.
7.2.1.5 Mould-release agent, such as silicone spray or silicone grease.
7.2.2 Number of test-pieces
Make two test-pieces from two mixes of the material.
Three more test-pieces (from three mixes of the material) are required if the result from one test-piece
meets the requirement specified in 5.3 and the other does not.
7.2.3 Test procedure
Coat the inside of the ring mould with a thin layer of mould release agent.
Mix according to 6.3, using a mass of powder with the appropriate volume of liquid to produce a mix
that is sufficient to fill the mould. Centre the mould on the glass plate and place the plate on the dental
vibrator platform. Vibrate the mix into the mould until it is slightly overfilled. Vibrate for a further
(20 ± 2) s. After this time, do not vibrate. Level the mix flush with the top of the mould and remove
the excess from the plate. 30 s after the end of mixing, lift the mould vertically from the plate using a
smooth action over a period of 5 s to allow the column of mix to slump onto the plate. As soon as the
material has set, measure the largest and smallest diameters on the base of the set test-piece to an
accuracy of 1 mm, and record the average value as the first result.
Repeat the test and record the second result, being the average of the two measurements made on the
second test-piece.
7.2.4 Evaluation of results
If both results meet the requirement (5.3), the product complies.
If neither result meets this requirement, then the product fails to comply.
If the result of one test meets this requirement and one fails to do so, repeat the test three more times.
If the results of all three of these additional tests meet the requirement (5.3) then the product complies.
Otherwise, it fails to comply.
7.2.5 Test report
Report
a) the result for every test conducted in accordance with 7.2.3, including those for additional test-
pieces (if these were required) and the average value (to 1 mm) for the results of those test-pieces
that comply with the requirement (5.3);
b) the value for the fluidity given by the manufacturer according to 8.3 a);
c) a statement that the product meets or does not meet the requirement for fluidity (5.3).
6 © ISO 2016 – All rights reserved

ISO 15912:2016(E)
7.3 Initial setting time
7.3.1 Apparatus
7.3.1.1 Needle penetrometer, an example of which is shown in Figure 1, meeting the specifications
of 7.3.1.1.1 to 7.3.1.1.5. The total mass of all parts that move (i.e. penetrometer needle, rod, scale and
compensating weight) shall be (300 ± 1) g.
7.3.1.1.1 Penetrometer needle (1), circular cross section with a squared-off end: length (50 ± 1) mm,
diameter 1,00 mm with a dimensional tolerance of h6 according to ISO 286-2.
7.3.1.1.2 Rod (2), of approximate dimensions 270 mm long and 10 mm in diameter.
7.3.1.1.3 Additional (compensating) weight (3).
7.3.1.1.4 Scale (4), graduated in millimetres.
7.3.1.1.5 Base-plate (6) of plate glass, measuring about 100 mm × 100 mm.
7.3.1.2 Ring mould, made from a corrosion-resistant, non-absorbent material, of which are two types.
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.
7.3.1.2.2 Small cylindrical mould, with an inside diameter of 30 mm and height of 25 mm.
For effective utilization of resources, the smaller mould may be used in the place of the larger mould. The
user will need to be aware that the lesser area of the small cylindrical mould allows fewer indentation
sites (according to 7.3.2) and as a consequence greater attention should 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.
ISO 15912:2016(E)
Key
1 penetrometer needle
2 rod
3 additional (compensating) weight
4 scale
5 scale adjustment locking screw
6 base-plate
7 stand
8 indicator
NOTE A ring mould is shown in place on the base-plate.
Figure 1 — Example of needle penetrometer
8 © ISO 2016 – All rights reserved

ISO 15912:2016(E)
7.3.2 Procedure
Adjust the vertical position of scale on the penetrometer for the indicator to read zero when the needle
is in contact with the base-plate and then lock the scale in this position by using the scale adjustment
locking screw. For this design, the scale is adjustable to allow zeroing (the zero point on the scale is at
the upper end). The scale is attached to the rod and moves (relative to the fixed indicator) when the rod
is raised. An alternative design is possible and permitted if it produces the same relative movement
between the scale and indicator, to record the movement of the needle.
Coat the inside of the ring mould with a thin layer of mould release agent and place the mould on
the base-plate.
Mix the material according to 6.3, using a mass of powder with the appropriate volume of liquid to
produce a mix that is sufficient to fill the mould.
If the larger mould is used, add 400 g of powder to the manufacturer’s recommended quantity of liquid
in a mixing bowl. If the smaller mould is used, add 100 g of powder to the manufacturer’s recommended
quantity of liquid in a mixing bowl.
Continue to run the timer that is used during mixing after mixing is completed. Use the time displayed
as the reference time for subsequent timed actions.
With the ring mould positioned beside the needle, overfill the ring mould with the mix and then level
the surface to be flush with the top of the mould. Beginning at a time that is before half the initial
setting time given by the manufacturer [according to 8.3 b)], make the first reading as follows.
a) Raise the rod for the needle to be above the surface of the mix. Reposition the mould to allow
penetration of the material at a site which is at least 10 mm from the wall of the larger mould, or
5 mm from the wall of the smaller mould.
b) Bring the needle tip into contact with the surface of the mix and hold.
c) Release the rod gently and record the time of this release. Allow it to sink through the material
under the force from the 300 g mass. Raise the rod as soon as the needle has penetrated a depth
that is within 5 mm from the base-plate.
NOTE It is not necessary to wait until the needle has touched the base-plate. Readings are taken at
(15 ± 1) s intervals and for this to be achieved there must be sufficient time after raising the rod for steps
7.3.2 d) and e) to be completed before the rod is released for the next penetration, 7.3.2 f).
Take subsequent readings, at (15 ± 1) s intervals after the release time recorded for first reading, as
follows.
d)
...