EN ISO 7494-2:2015

SLOVENSKI STANDARD
01-julij-2015
1DGRPHãþD
SIST EN ISO 11144:2000
SIST EN ISO 7494-2:2003
Zobozdravstvo - Zobozdravstvene enote - 2. del: Zrak, voda, sukcija (aspiracija) in
sistemi odpadnih voda (ISO 7494-2:2015)
Dentistry - Dental units - Part 2: Air, water, suction and wastewater systems (ISO 7494-
2:2015)
Zahnheilkunde - Zahnärztliche Behandlungseinheiten - Teil 2: Luft, Wasser, Absaugung
und Abwassersystem (ISO 7494-2:2015)
Médecine bucco-dentaire - Units dentaires - Partie 2: Systèmes d'alimentation en air et
en eau, d'aspiration et d'évacuation des eaux usées (ISO 7494-2:2015)
Ta slovenski standard je istoveten z: EN ISO 7494-2:2015
ICS:
11.060.20 =RERWHKQLþQDRSUHPD Dental equipment
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD
EN ISO 7494-2
NORME EUROPÉENNE
EUROPÄISCHE NORM
April 2015
ICS 11.060.20 Supersedes EN ISO 11144:1996, EN ISO 7494-2:2003
English Version
Dentistry - Dental units - Part 2: Air, water, suction and
wastewater systems (ISO 7494-2:2015)
Médecine bucco-dentaire - Units dentaires - Partie 2: Zahnheilkunde - Zahnärztliche Behandlungseinheiten - Teil
Systèmes d'alimentation en air et en eau, d'aspiration et 2: Luft, Wasser, Absaugung und Abwassersystem (ISO
d'évacuation des eaux usées (ISO 7494-2:2015) 7494-2:2015)
This European Standard was approved by CEN on 10 January 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
© 2015 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 7494-2:2015 E
worldwide for CEN national Members.

Contents Page
Foreword .3

Foreword
This document (EN ISO 7494-2:2015) 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 2015, and conflicting national standards shall be withdrawn at
the latest by October 2015.
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 7494-2:2003 and EN ISO 11144:1996.
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 7494-2:2015 has been approved by CEN as EN ISO 7494-2:2015 without any modification.
INTERNATIONAL ISO
STANDARD 7494-2
Second edition
2015-04-01
Dentistry — Dental units —
Part 2:
Air, water, suction and wastewater
systems
Médecine bucco-dentaire — Units dentaires —
Partie 2: Systèmes d’alimentation en air et en eau, d’aspiration et
d’évacuation des eaux usées
Reference number
ISO 7494-2:2015(E)
©
ISO 2015
ISO 7494-2:2015(E)
© ISO 2015
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 2015 – All rights reserved

ISO 7494-2:2015(E)
Contents Page
Foreword .v
Introduction .vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Classification . 4
4.1 Classification of suction systems . 4
4.2 Classification of suction air volume flow rate . 4
5 Requirements . 4
5.1 Requirements for supply connections . 4
5.2 Requirements for water and wastewater systems . 4
5.2.1 Incoming water . 5
5.2.2 Materials used for construction of procedural water systems within the
dental unit. 6
5.2.3 Backflow prevention device for dental units connected to the external
drinking water supply . 7
5.2.4 Cuspidors . . 7
5.2.5 Water venturi . 7
5.2.6 Particle filter . 7
5.2.7 Bacterial filter . 7
5.2.8 Bottled water system supplying procedural water or solution . 7
5.2.9 Retraction . 7
5.2.10 Water disinfection systems . 7
5.2.11 Water sampling connection point . 8
5.2.12 Wastewater drain connection. 8
5.3 Requirements for the air system . 8
5.3.1 Incoming air (dental air) . 8
5.3.2 Particle filters . 8
5.3.3 Bacterial filters . 9
5.4 Requirements for dental unit suction systems . 9
5.4.1 Static vacuum pressure . 9
5.4.2 Head loss . 9
5.4.3 Air separators . 9
5.4.4 Cannula connectors and cannula . 9
5.4.5 Operating hoses with cannula connectors .10
5.4.6 Solids filter .11
5.4.7 Noise level .11
5.4.8 Dental unit suction source connection point .11
6 Sampling .11
7 Tests .11
7.1 Cuspidors .11
7.2 Water venturi .11
7.3 Systems directly connected to external drinking water supply .11
7.4 Bottled water system supplying procedural water or solution .11
7.5 Retraction .12
7.6 Particle filters .12
7.7 Bacterial filters .12
7.8 Water disinfection systems .12
7.9 Tests for dental unit suction systems .13
7.9.1 Static vacuum pressure test .13
7.9.2 Head loss test .13
7.9.3 Measurement of noise level .14
ISO 7494-2:2015(E)
7.10 Water sampling connection point .15
7.11 Incoming water and air quality .15
7.12 Supply connections .15
8 Manufacturer’s instructions for use .15
9 Technical description .16
Annex A (informative) Schematic diagram of possible components and connections in a
dental unit .18
Annex B (informative) Test sequences .20
Bibliography .25
iv © ISO 2015 – All rights reserved

ISO 7494-2:2015(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 SC 6, Dental equipment.
This edition of ISO 7494-2 cancels and replaces ISO 7494-2:2003 and ISO 11144, of which it constitutes a
technical revision, while only replacing certain requirements specific to dental units given in ISO 10637.
In addition, it consolidates and updates requirements formerly specified in
— ISO 10637:1999, Dental equipment — High- and medium-volume suction systems, and
— ISO 11144:1995, Dental equipment — Connections for supply and waste lines.
ISO 7494 consists of the following parts, under the general title Dentistry — Dental units:
— Part 1: General requirements and test methods
— Part 2: Air, water, suction and wastewater systems
ISO 7494-2:2015(E)
Introduction
This part of ISO 7494 specifies requirements and test methods pertaining to components of the dental
unit which convey air, water, suction, and wastewater. The requirements in this part of ISO 7494
focus on certain technical aspects regarded by the working group to be appropriate for international
standardization. The working group acknowledges that requirements for microbiological aspects of
the fluids transported by dental units are also worthy of standardization and is working to develop
requirements pertaining to the prevention, inhibition, and removal of dental unit waterline biofilm.
Additional projects to develop microbiological requirements for air, water, and/or suction may follow.
vi © ISO 2015 – All rights reserved

INTERNATIONAL STANDARD ISO 7494-2:2015(E)
Dentistry — Dental units —
Part 2:
Air, water, suction and wastewater systems
1 Scope
This part of ISO 7494 specifies requirements and test methods concerning
a) the configuration of dental unit connections to the compressed air supply, water supply, suction
supply, and wastewater drain plumbing,
b) the materials, design, and construction of the compressed air and water system within the dental unit,
c) the quality for incoming water and air, and
d) the performance of dental unit suction system.
This part of ISO 7494 also specifies requirements for instructions for use and technical description.
This part of ISO 7494 is limited to dental units that are not used for life support treatment of ambulatory
patients or for oral surgery treatment requiring sterile air and water supplies. Amalgam separators are
not included in this International Standard.
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 1942, Dentistry — Vocabulary
ISO 7494-1:2011, Dentistry — Dental units — Part 1: General requirements and test methods
ISO 8573-1, Compressed air — Part 1: Contaminants and purity classes
ISO 9168, Dentistry — Hose connectors for air driven dental handpieces
ISO 10637:1999, Dental equipment — High- and medium-volume suction systems
ISO 14971, Medical devices — Application of risk management to medical devices
IEC 61672-1, Electroacoustics — Sound level meters — Part 1: Specifications
IEC 62366, Medical devices — Application of usability engineering to medical devices
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 1942 and ISO 7494-1 and the
following apply.
3.1
air separator
apparatus which separates liquids and solids from the suction air
ISO 7494-2:2015(E)
3.2
bacterial filter
filter designed to restrict the passage of bacteria and reduce bacteria in the procedural water or in the
compressed air
3.3
backflow
flow of water and/or another medium back into the external drinking water supply
3.4
backflow prevention device
safety device to prevent backflow
3.5
bottled water system
dental unit water system in which procedural water is supplied by an included reservoir which is not
connected to an external drinking water supply system and is manually filled with incoming water or
incoming solution
3.6
cannula connector
component at the end of the dental suction operating hose, which joins the cannula to the operating hose
3.7
dental air
compressed air supplied through the dental unit for powering, controlling, and/or assisting various
dental instruments and equipment, as well as for assisting practitioners with procedures in the oral
cavity, but not for procedures requiring medical air or sterile air, such as endoscopy, oral surgery,
analgesia, and life support
3.8
dental treatment centre
combination of functional items for dental use which consist, for example, of dental unit, dental patient
chair, and interconnected sub-units of dental equipment and instruments providing a functional
environment for dental care
3.9
dental unit suction system
passive entity, including all the components from the dental unit suction source connection point through the
cannula connector, which can induce air flow when connected to a suction source to evacuate solids, liquids,
aerosols and gases from the oral cavity and immediate surrounding area during oral treatment procedures
3.10
dental unit suction source connection point
any port on the dental unit for connection to a supply of dental suction
3.11
filter
apparatus which restricts targeted constituents from passing through it
3.12
incoming air
compressed air supplied to the dental unit
3.13
incoming air connection point
any port on the dental unit for connection to an external compressed air supply
2 © ISO 2015 – All rights reserved

ISO 7494-2:2015(E)
3.14
incoming solution
solution of substances specified by the manufacturer, and introduced in combination with, or in place
of, the incoming water in order to improve or maintain the quality of the procedural water or for other
reasons, such as coolant for cutting burs or medicament for oral cavity
3.15
incoming water
water supplied to the dental unit for procedural use or non-procedural use
3.16
incoming water connection point
any port on the dental unit for connection to an external drinking water supply
3.17
non-procedural water
water supplied by the dental unit for purposes other than use in the oral cavity
EXAMPLE Cuspidor bowl rinse water, water venturi supply water.
3.18
procedural water
water supplied by the dental unit for use in the oral cavity
EXAMPLE Handpiece coolant water, multifunction handpieces (syringes) water, scaler coolant water, cup fill
water.
3.19
retraction
re-entry of water, air, and/or other medium into the dental unit or the dental instruments due to flow
reversal, e.g. caused by momentary dynamic pressure variations during turning off the instruments
3.20
rinse water
water for cleaning
3.21
spill-over level
highest possible level of water or solution in a device above which the fluid will flow over the edge
3.22
suction system
active entity of dental equipment, including a suction source equipment, which enables an air flow to
be induced which is designed to remove spray, liquids, and solids from the mouth of the dental patient
during dental treatment
3.23
wastewater
solution that is discharged into the drainage system by way of the cuspidor drain, saliva ejector, air
separator, amalgam separator, or other dental unit component or system
3.24
water disinfection system
system designed to reduce the microbiological contamination in a dental unit procedural water
3.25
water venturi
device using waterflow to produce a suction
3.26
wastewater connection point
port for the connection through which wastewater flows and is discharged into the drains
ISO 7494-2:2015(E)
4 Classification
4.1 Classification of suction systems
According to ISO 10637:1999, suction systems are classified to the type of suction as follows:
a) dry system;
b) semi-dry system;
c) wet system.
4.2 Classification of suction air volume flow rate
According to ISO 10637:1999, suction systems are classified to the type of air volume flow rate as follows:
1)
a) type 1: high-volume suction system, suction system with an air intake of more than 250 Nl/min at
the suction cannula connector;
b) type 2: medium-volume suction system, suction system with an air intake between 90 Nl/min and
1)
250 Nl/min at the suction cannula connector.
5 Requirements
5.1 Requirements for supply connections
The manufacturer’s technical description shall include the configuration of the supply connections for
the dental unit. The specified configuration of the supply connections shall lie within a maximum area
of 180 mm × 220 mm.
The manufacturer’s technical description shall include detailed information of the position and
the dimensions of supply connections (see keys 1 to 5 in Figure 1) for the dental unit in the dental
treatment centre.
In the dental treatment centre, often a core hole in the floor with a diameter of 160 mm is used. Therefore,
it is recommended to place the supply connections within this diameter.
An example of the configuration and the connection points is given in Figure 1.
Dimensions for the connections for electricity and compressed air areas (see keys 4 and 5 in Figure 1)
are given as maximum values.
Dimensions for plumbing holes (see keys 1, 2, and 3 in Figure 1) are given as minimum values. The
diameters specify the free space required for tubes and hoses.
The holes without dimensions can be positioned anywhere inside the connection area.
Gas tubing, if required, shall not be located inside the areas specified in Figure 1.
The location of other utility connections which are not indicated shall be specified by the manufacturer.
This test is in accordance with 7.12.
5.2 Requirements for water and wastewater systems
NOTE A schematic diagram of possible water and wastewater systems is given as example in Figure A.1.
1) Nl/min indicates normal litres per minute, the amount of air that flows through a pipe calculated back to
2 5 2
“normal” conditions [0 °C and 1 atm or 1,01325 bar (1 bar = 0,1 MPa = 0,1 N/mm = 10 N/m )].
4 © ISO 2015 – All rights reserved

ISO 7494-2:2015(E)
5.2.1 Incoming water
The manufacturer’s instructions for use and technical description shall specify the requirements for the
incoming water to be supplied to the dental unit, including the following parameters.
The following values are recommendations:
a) water pressure limits (2 bar to 6 bar);
b) water flow rate limit (greater than 5 l/min);
c) water hardness limit [less than 2,14 mmol/l (<12 °dH)];
d) pH limits (6,5 to 8,5);
e) maximum particle size (<100 µm);
f) conformance to local drinking water regulations.
This test is in accordance with 7.11.
ISO 7494-2:2015(E)
Key
1 wastewater connection point
2 incoming water connection point
3 dental unit suction source connection point
4 connection area for electricity and telecommunication
5 connection area for incoming air
Figure 1 — Configuration example of connection points and adjacent supply areas
5.2.2 Materials used for construction of procedural water systems within the dental unit
The dental unit shall be designed and constructed in such a way that the materials which come into
contact with the procedural water or solutions or that are likely to come into contact with them do not
cause an unacceptable risk to the quality of the procedural water or solution.
The materials used within the water path shall be documented by the manufacturer. The materials used
shall be evaluated by risk analysis to ensure that they do not cause an unacceptable risk to the quality
of procedural water or solution.
Manufacturers shall document this risk analysis in accordance with ISO 14971.
6 © ISO 2015 – All rights reserved
Ø52
Ø36
Ø52
80 60 80
ISO 7494-2:2015(E)
5.2.3 Backflow prevention device for dental units connected to the external drinking water supply
Dental units directly connected to the external drinking water supply system and using this water as
procedural water shall have a backflow prevention device at the connection point with the water supply
or an air gap of not less than 20 mm.
This test is in accordance with 7.3.
5.2.4 Cuspidors
The point where the cuspidor rinse water is dispensed shall be at least 20 mm above the spill-over level
of the cuspidor.
This test is in accordance with 7.1.
5.2.5 Water venturi
Water venturi for suction of saliva and wastewater shall only be used if an additional backflow prevention
device is installed at the connection point of the water venturi device.
This test is in accordance with 7.2.
5.2.6 Particle filter
A dental unit directly connected to an external drinking water supply or a bottled water system shall
have at least one particle filter with an effective mesh size not greater than 100 μm installed at the
incoming water connection point.
This test is in accordance with 7.6.
5.2.7 Bacterial filter
If the dental unit water supply is equipped with a filter intended to restrict the passage of bacteria, the
bacterial filter shall be rated to restrict the passage of contaminants larger than 0,22 μm. The dental
unit manufacturer shall provide maintenance instructions and schedule for the bacterial filter.
This test is in accordance with 7.7.
5.2.8 Bottled water system supplying procedural water or solution
These systems shall either be completely separated from the external drinking water supply system or shall
have a backflow prevention device at the connection point with the external drinking water supply system.
This test is in accordance with 7.4.
5.2.9 Retraction
The volume of the retraction of procedural water or solution shall not exceed 40 mm (= 0,04 ml).
This test is in accordance with 7.5.
5.2.10 Water disinfection systems
These systems shall either be completely separated from the external drinking water supply system or shall
have a backflow prevention device at the connection point with the external drinking water supply system.
The manufacturer shall supply information about the water disinfection solution and instructions for
use and maintenance.
ISO 7494-2:2015(E)
The manufacturer shall ensure that the use of these chemicals does not adversely affect the water
quality and shall specify the recommended maintenance frequency.
If a water disinfection system is installed in a dental unit, it shall be tested in accordance with 7.8.
5.2.11 Water sampling connection point
For dental units directly connected to the external drinking water supply, the manufacturer’s technical
description should include a recommendation to install a sampling point for incoming water at or near
the incoming water connection point.
NOTE See Figure A.1, key 25.
If the manufacturer recommends installing a sampling point, the instructions for use shall give
information about collecting samples of water and the technical description shall provide information
about the installation and collection of water samples.
This test is in accordance with 7.10.
5.2.12 Wastewater drain connection
The manufacturer’s technical description shall specify the maximum wastewater flow rate from the
dental unit that the drain shall be capable of accommodating.
The manufacturer’s technical description shall specify the minimum gradient of the wastewater lines.
Check the technical description to ensure that all information specified is provided.
5.3 Requirements for the air system
NOTE A schematic diagram of possible air connections in dental units is given as example in Figure A.1.
5.3.1 Incoming air (dental air)
The manufacturer’s instructions for use and the technical description shall specify requirements for the
incoming air to be supplied to the dental unit, including the following parameters.
The following values are recommendations:
a) air pressure limits (7 ± 1) bar;
b) air flow rate limit (greater than 80 Nl/min);
c) humidity limit (dew point not greater than −20 °C at atmospheric pressure);
d) oil contamination limit (max. 0,5 mg/m );
e) particulate contamination limit (not greater than 100 particles per cubic meter for 1 µm to 5 µm
particle size).
This test is in accordance with 7.11 and shall conform to ISO 8573-1.
5.3.2 Particle filters
A filter with an effective mesh size not exceeding 50 µm shall be installed at the incoming air connection
point of the dental unit.
This test is in accordance with 7.6.
8 © ISO 2015 – All rights reserved

ISO 7494-2:2015(E)
5.3.3 Bacterial filters
If the dental unit air supply is equipped with a filter intended to restrict the passage of bacteria, the
bacterial filter shall be rated to restrict the passage of contaminants larger than 0,22 μm. The dental
unit manufacturer shall provide maintenance instructions and schedule for the bacterial filter.
This test is in accordance with 7.7.
5.4 Requirements for dental unit suction systems
NOTE A schematic diagram of possible suction connections in dental units is given as example in Figure A.1.
5.4.1 Static vacuum pressure
The manufacturer of the dental unit shall specify the minimum and the maximum vacuum pressure that
is to be supplied to the dental unit at the suction connection point under static (i.e. no flow) conditions
in the technical description.
If the dental unit is equipped with a vacuum-limiting device, the manufacturer shall specify the maximum
vacuum pressure available at the cannula connector under static conditions.
The dental unit suction systems shall withstand the maximum vacuum pressure supplied to the dental
unit per manufacturer specifications without damage to its materials or components.
This test is in accordance with 7.9.1.
5.4.2 Head loss
The manufacturer shall measure and report in the technical description the pressure head loss between
the dental unit suction source connection point and the atmospheric end of the cannula (with cannula
recommended by the dental unit manufacturer installed) at each of the following flow rates:
2)
90 Nl/min, 150 Nl/min, 200 Nl/min, 250 Nl/min, 300 Nl/min, 350 Nl/min, and 400 Nl/min .
Measurements are not required at flow rates which require the vacuum pressure to exceed the
maximum pressure specified by the manufacturer. Results at additional flow rates may be reported at
the manufacturer’s discretion in the technical description.
Measurements shall be made in accordance with 7.9.2.
NOTE This information helps parties responsible for specifying complete suction systems (i.e. suction
source equipment, piping systems, and dental unit suction systems) to meet the flow performance requirements
specified by a dental clinic.
5.4.3 Air separators
Maintenance of air separators shall conform to IEC 62366.
5.4.4 Cannula connectors and cannula
5.4.4.1 Cannula connector manufacturers shall state a nominal size of the connector and specify the
requirements for cannula that can be used with the connector.
5.4.4.2 Cannula connectors shall allow access of the cannula to every part of the patient’s mouth
without causing distortion of the hoses.
2) Nl/min indicates normal litres per minute, the amount of air that flows through a pipe calculated back to
2 5 2
“normal” conditions [0 °C and 1 atm or 1,01325 bar (1 bar = 0,1 MPa = 0,1 N/mm = 10 N/m )].
ISO 7494-2:2015(E)
5.4.4.3 The forces to insert and remove the cannula from the cannula connector shall conform to
IEC 62366 when the connector is used with cannula that meet the connector manufacturer’s cannula
requirements.
5.4.4.4 The design of the connection between the cannula and cannula connector shall be at the
discretion of the manufacturer. An example of a connection design is provided in Figure 2 and Table 1.
Dimensions in millimetres
L L
2 1
a) Cannula b) Cannula connector
Key
d nominal inside diameter cannula
D inside diameter cannula connector
D outside diameter cannula
L inside taper length cannula connector
L outside taper length cannula
Figure 2 — Example of design of interface between cannula and cannula connector
Table 1 — Example of dimensions of interface between cannula and cannula connector
Dimensions in millimetres
d D D L L
1 1 2 1 2
15 ± 1 14,9 + 0,2 16,1 − 0,2 18 − 1 15 − 1
11 ± 1 10,9 + 0,2 12,1 − 0,2 18 − 1 15 − 1
≥ 6
for medium-volume suction
system Dimensions and tolerances given by the manufacturer
Compliance shall be verified using readily available measuring instruments.
5.4.5 Operating hoses with cannula connectors
Operating hoses shall have an internally smooth surface and shall be flexible.
Operating hoses should be easily cleaned by methods and with agents recommended by the dental unit
manufacturer.
Compliance shall be verified by visual inspection and shall conform to IEC 62336.
10 © ISO 2015 – All rights reserved
+30'
1,5° 0
+30'
1,5° 0
d
D
D
ISO 7494-2:2015(E)
5.4.6 Solids filter
Solids filter for suction systems shall be located at the dental unit in such a way to allow easy removal
for maintenance.
If an air separator is included in the dental unit, the solids filter shall be placed to ensure proper function
of the air separator.
The solids filter shall have a mesh size determined by the manufacturer and specified in the instructions
for use and in the technical description.
Compliance of the solids filter location shall be verified by visual inspection.
5.4.7 Noise level
The A-weighted noise level generated by high-volume and medium-volume suction systems through the
connected cannula shall not exceed 65 dB (A) at a distance of 0,50 m from the cannula connector and
with the cannula recommended by the manufacturer of the dental unit.
Testing shall be carried out in accordance with 7.9.3.
5.4.8 Dental unit suction source connection point
The manufacturer’s technical description shall include the connection dimensions.
Check the technical description to ensure that all information specified is provided.
6 Sampling
One representative sample of the dental unit water and air supply and suction systems being tested
shall be selected.
7 Tests
7.1 Cuspidors
Check by visual inspection whether the rinse water is dispersed above the spill-over level of the
wastewater. Then, measure the distance of the air gap between the lowest point of the rinse water outlet
and the spill-over level with a readily available measuring device.
7.2 Water venturi
Check by visual inspection that a backflow prevention device is installed at the connection point of the
water venturi device.
7.3 Systems directly connected to external drinking water supply
Check by visual inspection whether a backflow prevention device or an air gap is installed at the incoming
water connection point. Measure the distance of the air gap with a measuring device.
7.4 Bottled water system supplying procedural water or solution
Check by visual inspection if the bottled water system is separated from the external drinking water
supply. If not, check by visual inspection if a backflow prevention device is installed at the incoming
water connection point.
ISO 7494-2:2015(E)
7.5 Retraction
Connect the handpiece hose to the dental unit. Then connect a transparent hose of (L = 150 ± 2) mm length
and (d = 1,5 ± 0,1) mm internal diameter to the water fitting to which the handpiece is normally attached.
Measure the volume of retraction in the transparent hose.
The unconnected end of the transparent hose shall be squared off.
Operate the dental unit’s valve as it would normally be done when activating the water flow for the
handpiece to ensure that the vertically held hose is completely filled. Operate the dental unit’s water
valve as it would normally be done when shutting off the handpiece. The meniscus of the column of
water in the hose shall not be more than a distance of l = 20 mm from the end of the hose when held
vertically, with the open hose end extending upward. See Figure 3.
l
L
Key
1 water
2 exhaust
3 drive air
4 example of the type 4 connector from ISO 9168
5 transparent hose
Figure 3 — Configuration of retraction test apparatus in connection with a hose connector type
7.6 Particle filters
Check by visual inspection whether a particle filter is installed at the incoming water and/or air
connection points. Check the instructi
...