EN 60393-1:2009

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Potenciometri za elektronsko opremo - 1. del: Rodovna specifikacija (IEC 60393-1:2008)Potentiometer zur Verwendung in Geräten der Elektronik - Teil 1: Fachgrundspezifikation (IEC 60393-1:2008)Potentiomètres utilisés dans les équipements électroniques - Partie 1: Spécification générique (CEI 60393-1:2008)Potentiometers for use in electronic equipment - Part 1: Generic specification (IEC 60393-1:2008)31.040.20Potenciometri, spremenljivi uporiPotentiometers, variable resistorsICS:Ta slovenski standard je istoveten z:EN 60393-1:2009SIST EN 60393-1:2009en01-oktober-2009SIST EN 60393-1:2009SLOVENSKI
STANDARD
EUROPEAN STANDARD EN 60393-1 NORME EUROPÉENNE
EUROPÄISCHE NORM July 2009
CENELEC European Committee for Electrotechnical Standardization Comité Européen de Normalisation Electrotechnique Europäisches Komitee für Elektrotechnische Normung
Central Secretariat: Avenue Marnix 17, B - 1000 Brussels
© 2009 CENELEC -
All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.
Ref. No. EN 60393-1:2009 E
ICS 31.040.20 Supersedes CECC 41 000:1976
English version
Potentiometers for use in electronic equipment -
Part 1: Generic specification (IEC 60393-1:2008)
Potentiomètres utilisés
dans les équipements électroniques -
Partie 1: Spécification générique (CEI 60393-1:2008)
Potentiometer zur Verwendung
in Geräten der Elektronik -
Teil 1: Fachgrundspezifikation (IEC 60393-1:2008)
This European Standard was approved by CENELEC on 2009-07-01. CENELEC 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 Central Secretariat or to any CENELEC 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 CENELEC member into its own language and notified to the Central Secretariat has the same status as the official versions.
CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Cyprus, the Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom.
Foreword The text of document 40/1897/FDIS, future edition 3 of IEC 60393-1, prepared by IEC TC 40, Capacitors and resistors for electronic equipment, was submitted to the IEC-CENELEC parallel vote and was approved by CENELEC as EN 60393-1 on 2009-07-01. This European Standard supersedes CECC 41 000:1976. The following dates were fixed: – latest date by which the EN has to be implemented
at national level by publication of an identical
national standard or by endorsement
(dop)
2010-04-01 – latest date by which the national standards conflicting
with the EN have to be withdrawn
(dow)
2012-07-01 Annex ZA has been added by CENELEC. __________ Endorsement notice The text of the International Standard IEC 60393-1:2008 was approved by CENELEC as a European Standard without any modification. __________
- 3 - EN 60393-1:2009 Annex ZA (normative)
Normative references to international publications with their corresponding European publications
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.
NOTE
When an international publication has been modified by common modifications, indicated by (mod), the relevant EN/HD applies.
Publication Year Title EN/HD Year
IEC 60027-1 -1) Letter symbols to be used in electrical technology -
Part 1: General EN 60027-1 20062)
IEC 60050 Series International Electrotechnical Vocabulary (IEV) - -
IEC 60062 -1) Marking codes for resistors and capacitors EN 60062 + corr. January
20052) 2007
IEC 60063 A1 A2 1963 1967 1977 Preferred number series for resistors and capacitors - -
IEC 60068-1 + corr. October
+ A1 1988 1988 1992 Environmental testing -
Part 1: General and guidance
EN 60068-1
IEC 60068-2-1 A1 A2 1990 1993 1994 Environmental testing -
Part 2: Tests - Tests A: Cold EN 60068-2-13) A1 A2
1993 1993 1994
IEC 60068-2-2 A1 A2 1974 1993 1994 Environmental testing -
Part 2: Tests - Tests B: Dry heat EN 60068-2-24)
A1 A2
1993 1993 1994
IEC 60068-2-6 -1) Environmental testing -
Part 2: Tests - Test Fc: Vibration (sinusoidal) EN 60068-2-6 20082)
IEC 60068-2-13 -1) Environmental testing -
Part 2: Tests - Test M: Low air pressure EN 60068-2-13 19992)
IEC 60068-2-14 + A1 1984 1986 Environmental testing -
Part 2: Tests - Test N: Change of
temperature
EN 60068-2-14
IEC 60068-2-17 -1) Environmental testing -
Part 2: Tests - Test Q: Sealing EN 60068-2-17 19942)
IEC 60068-2-20 + A2 1979 1987 Environmental testing -
Part 2: Tests - Test T: Soldering
HD 323.2.20 S35)
IEC 60068-2-21 -1) Environmental testing -
Part 2-21: Tests - Test U: Robustness of terminations and integral mounting devices EN 60068-2-21 20062)
1)
Undated reference. 2)
Valid edition at date of issue. 3)
EN 60068-2-1 is superseded by EN 60068-2-1:2007, which is based on IEC 60068-2-1:2007. 4)
EN 60068-2-2 includes supplement A:1976 to IEC 60068-2-2; it is superseded by EN 60068-2-2:2007, which is based on IEC 60068-2-2:2007 5)
HD 323.2.20 S3 is superseded by EN 60068-2-20:2008, which is based on IEC 60068-2-20:2008. SIST EN 60393-1:2009

Publication Year Title EN/HD Year
IEC 60068-2-27 -1) Environmental testing -
Part 2: Tests - Test Ea and guidance: Shock EN 60068-2-27 20092)
IEC 60068-2-29 -1) Environmental testing -
Part 2: Tests - Test Eb and guidance: Bump EN 60068-2-296)
19932)
IEC 60068-2-30 -1) Environmental testing -
Part 2-30: Tests - Test Db: Damp heat, cyclic (12 h + 12 h cycle) EN 60068-2-30 20052)
IEC 60068-2-45 A1 1980 1993 Environmental testing -
Part 2: Tests - Test XA and guidance: Immersion in cleaning solvents EN 60068-2-45 A1 1992 1993
IEC 60068-2-58 -1) Environmental testing -
Part 2-58: Tests - Test Td: Test methods for solderability, resistance to dissolution of metallization and to soldering heat of surface mounting devices (SMD) EN 60068-2-58 + corr. December
20042) 2004
IEC 60068-2-78 -1) Environmental testing -
Part 2-78: Tests - Test Cab: Damp heat, steady state EN 60068-2-78 20012)
IEC 60410 -1) Sampling plans and procedures
for inspection by attributes - -
IEC 60617 Data-base Graphical symbols for diagrams - -
IEC 60915 -1) Capacitors and resistors for use in electronic equipment - Preferred dimensions of shaft ends, bushes and for the mounting of single-hole, bush-mounted, shaft-operated electronic components EN 60915 + corr. April
20072) 2009
IEC 61249-2-7 -1) Materials for printed boards and other interconnecting structures -
Part 2-7: Reinforced base materials, clad and unclad - Epoxide woven E-glass laminated sheet of defined flammability (vertical burning test), copper-clad EN 61249-2-7 + corr. September 20022) 2005
IEC QC 001002-3 -1) IEC Quality Assessment System
for Electronic Components (IECQ) - Rules of Procedure -
Part 3: Approval procedures - -
IEC QC 001005 -1) IEC Quality Assessment System
for Electronic Components (IECQ) - Register of films, products and services approved under the IECQ system, including ISO 9000 - -
ISO 1000 -1) SI units and recommendations for the use of their multiples and of certain other units - -
ISO 9000 -1) Quality management systems -
Fundamentals and vocabulary EN ISO 9000 20052)
6)
EN 60068-2-29 is superseded by EN 60068-2-27:2009, which is based on IEC 60068-2-27:2008. SIST EN 60393-1:2009

IEC 60393-1Edition 3.0 2008-05INTERNATIONAL STANDARD
Potentiometers for use in electronic equipment –
Part 1: Generic specification INTERNATIONAL ELECTROTECHNICAL COMMISSION XDICS 31.040.20 PRICE CODEISBN 2-8318-9748-3
– 2 – 60393-1 © IEC:2008(E) CONTENTS FOREWORD.6
1 General.8 1.1 Scope.8 1.2 Normative references.8 2 Technical data.10 2.1 Units and symbols.10 2.2 Terms and definitions.10 2.3 Preferred values.28 2.4 Marking.28 3 Assessment procedures.28 4 Test and measurement procedures.28 4.1 General.28 4.2 Standard atmospheric conditions.29 4.3 Drying.30 4.4 Visual examination and check of dimensions.30 4.5 Continuity (except for continuously rotating potentiometers).32 4.6 Element resistance.32 4.7 Terminal resistance.33 4.8 Maximum attenuation.33 4.9 Resistance law (conformity).33 4.10 Matching of the resistance law (for ganged potentiometers only).34 4.11 Switch contact resistance (when appropriate).34 4.12 Voltage proof (insulated styles only).38 4.13 Insulation resistance (insulated styles only).39 4.14 Variation of resistance with temperature.40 4.15 Rotational noise.42 4.16 Contact resistance at low-voltage levels.44 4.17 Setting ability (adjustability) and setting stability.45 4.18 Starting torque.49 4.19 Switch torque.49 4.20 End stop torque.50 4.21 Locking torque.50 4.22 Thrust and pull on shaft.51 4.23 Shaft run-out.52 4.24 Lateral run-out.53 4.25 Pilot (or spigot) diameter run-out.53 4.26 Shaft end play.54 4.27 Backlash.55 4.28 Dither.57 4.29 Output smoothness.58 4.30 Robustness of terminals.59 4.31 Sealing.60 4.32 Solderability.61 4.33 Resistance to soldering heat.61 4.34 Change of temperature.62 SIST EN 60393-1:2009

60393-1 © IEC:2008(E) – 3 – 4.35 Vibration.63 4.36 Bump.64 4.37 Shock.64 4.38 Climatic sequence.65 4.39 Damp heat, steady state.67 4.40 Mechanical endurance (potentiometers).68 4.41 AC endurance testing of mains switches on capacitive loads.71 4.42 DC endurance testing of switches.73 4.43 Electrical endurance.74 4.44 Component solvent resistance.78 4.45 Solvent resistance of the marking.78 4.46 Microlinearity.79 4.47 Mounting (for surface mount potentiometers).81 4.48 Shear (adhesion) test.83 4.49 Substrate bending test (formerly bond strength of the end face plating).83 4.50 Solderability (for surface mount potentiometers).83 4.51 Resistance to soldering heat (for surface mount potentiometers).83
Annex A (normative)
Rules for the preparation of detail specifications for capacitors
and resistors for electronic equipment.84 Annex B (normative)
Interpretation of sampling plans and procedures as described
in IEC 60410 for use within the IEC Quality Assessment System
for Electronic Components.85 Annex C (normative)
Measuring methods for rotational noise.86 Annex D (normative)
Apparatus for measuring mechanical accuracy.89 Annex E (normative)
Measuring method for microlinearity.90 Annex F (normative)
Preferred dimensions of shaft ends, bushes and for the mounting hole, bush-mounted, shaft-operated electronic components.92 Annex G (informative)
Example of common potentiometer’s law.93 Annex H (normative)
Quality assessment procedures.95
Figure 1 – Shaft-sealed potentiometer.14 Figure 2 – Shaft- and panel-sealed potentiometer.14 Figure 3 – Fully sealed potentiometer.14 Figure 4 – Linear law.16 Figure 5 – Logarithmic law.16 Figure 6 – Inverse logarithmic law.16 Figure 7 – Output ratio.17 Figure 8 – Loading error.18 Figure 9 – Total mechanical travel (or angle of rotation).18 Figure 10 – Conformity.20 Figure 11 – Absolute conformity.20 Figure 12 – Linearity.21 Figure 13 – Independent linearity.22 Figure 14 – Zero-based linearity.23 Figure 15 – Absolute linearity.24 SIST EN 60393-1:2009

– 4 – 60393-1 © IEC:2008(E) Figure 16 – Terminal based linearity.25 Figure 17 – Effective tap width.25 Figure 18 – Backlash.27 Figure 19 – Example of insulation resistance and voltage proof
test jig for surface mount potentiometers.39 Figure 20 – Test circuit contact resistance.45 Figure 21 – Measuring circuit for setting ability (as divider).46 Figure 22 – Measuring circuit for setting ability (as current controller).47 Figure 23 – Shaft run-out.52 Figure 24 – Lateral run-out.53 Figure 25 – Pilot (spigot) diameter run-out.54 Figure 26 – Shaft end play.55 Figure 27 – Test circuit for measurement of backlash.56 Figure 28 – Measurement of backlash.57 Figure 29 – Test circuit for measurement of output smoothness.58 Figure 30 – The circuit for continuous monitoring of the contact resistance.71 Figure 31 – Test circuit a.c. endurance testing.72 Figure 32 – Test circuit d.c. endurance testing.73 Figure 33 – Example of microlinearity measurement.79 Figure 34 – Block diagram of a circuit for evaluation of microlinearity.80 Figure 35 – Example of simultaneous evaluation of linearity and microlinearity.80 Figure 36 – Suitable substrate for mechanical and electrical tests
(may not be suitable for impedance measurements).82 Figure 37 – Suitable substrate for electrical tests.82 Figure C.1 – Measuring circuit for method A, rotational noise.87 Figure C.2 – Measuring circuit for CRV.87 Figure C.3 – Measuring circuit for ENR.88 Figure E.1 – Block diagram of a digital reference unit
(synthetic high-precision master).90 Figure G.1 – Definition of rotation (shaft-end view).93 Figure G.2 – Linear law, without centre tap.94 Figure G.3 – Linear law, with centre tap.94 Figure G.4 – Logarithmic law, without tap.94 Figure G.5 – Logarithmic law, with tap.94 Figure G.6 – Inverse logarithmic law without tap.94 Figure G.7 – Inverse logarithmic law with tap.94 Figure H.1 – General scheme for capability approval.98
Table 1 – Standard atmospheric conditions.30 Table 2 – Measuring voltages.32 Table 3 – Calculation of resistance value(R) and change in resistance (ûR).41 Table 4 – Calculation of temperature differences (∆T).41 Table 5 – Current values (IBb).43 Table 6 – Moving contact current.48 Table 7 – End stop torque.50 SIST EN 60393-1:2009

60393-1 © IEC:2008(E) – 5 – Table 8 – Locking torque.50 Table 9 – Shaft torque.51 Table 10 – Thrust and pull.51 Table 11 – Thrust and pull.52 Table 12 – Backlash.57 Table 13 – Dither for non-wire wound types.57 Table 14 – Dither for wire wound types (under consideration).58 Table 15 – Tensile force.59 Table 16 – Number of cycles.66 Table 17 – Number of cycles.69 Table 18 – Number of operations.73 Table 19 – Panel size.75 Table G.1 – Resistance law and code letter.93
– 6 – 60393-1 © IEC:2008(E) INTERNATIONAL ELECTROTECHNICAL COMMISSION ____________
POTENTIOMETERS FOR USE IN ELECTRONIC EQUIPMENT –
Part 1: Generic specification
FOREWORD 1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising all national electrotechnical committees (IEC National Committees). The object of IEC is to promote international co-operation on all questions concerning standardization in the electrical and electronic fields. To this end and in addition to other activities, IEC publishes International Standards, Technical Specifications, Technical Reports, Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC Publication(s)”). Their preparation is entrusted to technical committees; any IEC National Committee interested in the subject dealt with may participate in this preparatory work. International, governmental and non-governmental organizations liaising with the IEC also participate in this preparation. IEC collaborates closely with the International Organization for Standardization (ISO) in accordance with conditions determined by agreement between the two organizations. 2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international consensus of opinion on the relevant subjects since each technical committee has representation from all interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any misinterpretation by any end user. 4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications transparently to the maximum extent possible in their national and regional publications. Any divergence between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in the latter. 5) IEC provides no marking procedure to indicate its approval and cannot be rendered responsible for any equipment declared to be in conformity with an IEC Publication. 6) All users should ensure that they have the latest edition of this publication. 7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and members of its technical committees and IEC National Committees for any personal injury, property damage or other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC Publications.
8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is indispensable for the correct application of this publication. 9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of patent rights. IEC shall not be held responsible for identifying any or all such patent rights. International Standard IEC 60393-1 has been prepared by IEC technical committee 40: Capacitors and resistors for electronic equipment. This third edition cancels and replaces the second edition published in 1989 and constitutes a technical revision, including minor revisions related to tables, figures and references. This edition contains the following significant technical changes with respect to the previous edition: • implementation of Annex H which replaces Section 3 of the previous edition. The text of this standard is based on the following documents: FDIS Report on voting 40/1897/FDIS 40/1914/RVD
Full information on the voting for the approval of this standard can be found in the report on voting indicated in the above table. SIST EN 60393-1:2009

60393-1 © IEC:2008(E) – 7 – This publication has been drafted in accordance with the ISO/IEC Directives, Part 2. A list of all the parts of the IEC 60393 series, under the general title Potentiometers for use in electronic equipment, can be found on the IEC web site. The committee has decided that the contents of this publication will remain unchanged until the maintenance result date indicated on the IEC web site under "http://webstore.iec.ch" in the data related to the specific publication. At this date, the publication will be
• reconfirmed, • withdrawn, • replaced by a revised edition, or • amended. A bilingual version of this publication may be issued at a later date.
– 8 – 60393-1 © IEC:2008(E) POTENTIOMETERS FOR USE IN ELECTRONIC EQUIPMENT –
Part 1: Generic specification
1 General 1.1 Scope This part of IEC 60393 is applicable to all types of resistive potentiometers, including lead- screw actuated types, presets, multi-turn units, etc. to be used in electronic equipment. It establishes standard terms, inspection procedures and methods of test for use in sectional and detail specifications of electronic components for quality assessment or any other purpose. It has been mainly written, and the test methods described, to conform to the widely used single-turn rotary potentiometer with an operating shaft. For other types of potentiometers: • the angle of rotation may be several turns; • the reference to an operating shaft shall apply to any other actuating device; • the angular rotation shall be taken to mean mechanical travel of the actuating device; • a value for force shall be prescribed instead of a value for torque if the actuating device moves in a linear instead of a rotary manner. These alternative prescriptions will be found in the sectional or detail specification. When a component is constructed as a variable resistor, i.e. as a two-terminal device, the detail specification shall prescribe the modifications required in the standard tests. 1.2 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. IEC 60027-1, Letter symbols to be used in electrical technology – Part 1: General IEC 60050 (all parts), International Electrotechnical Vocabulary (IEV) IEC 60062, Marking codes for resistors and capacitors IEC 60063:1963, Preferred number series for resistors and capacitors
Amendment 1 (1967)
Amendment 2 (1977) IEC 60068-1:1988, Environmental testing – Part 1: General and guidance
Amendment 1 (1992) IEC 60068-2-1:1990, Environmental testing – Part 2: Tests – Tests A: Cold
Amendment 1 (1993)
Amendment 2 (1994) SIST EN 60393-1:2009

60393-1 © IEC:2008(E) – 9 – IEC 60068-2-2:1974, Environmental testing – Part 2: Tests – Tests B: Dry heat
Amendment 1 (1993)
Amendment 2 (1994)
IEC 60068-2-6, Environmental testing – Part 2: Tests – Test Fc : Vibration (sinusoidal) IEC 60068-2-13, Environmental testing – Part 2: Tests – Test M: Low air pressure IEC 60068-2-14:1994, Environmental testing – Part 2: Tests – Test N: Change of temperature Amendment 1 (1986) IEC 60068-2-17, Environmental testing – Part 2: Tests – Test Q: Sealing IEC 60068-2-20:1979, Environmental testing – Part 2: Tests – Test T: Soldering
Amendment 2 (1987) IEC 60068-2-21, Environmental testing – Part 2-21: Tests – Test U: Robustness of terminations and integral mounting devices
IEC 60068-2-27, Environmental testing – Part 2: Tests – Test Ea and guidance: Shock IEC 60068-2-29, Environmental testing – Part 2: Tests – Test Eb and guidance: Bump IEC 60068-2-30, Environmental testing – Part 2-30: Tests – Test dB : Damp heat, cyclic (12 h + 12 hour cycle) IEC 60068-2-45:1980, Environmental testing – Part 2: Tests – Test XA and guidance: Immersion in cleaning solvents
Amendment 1 (1993) IEC 60068-2-58, Environmental testing
Part 2-58: Tests – Test Td: Test methods for solderability, resistance to dissolution of metallization and to soldering heat of surface mounting devices (SMD) IEC 60068-2-78, Environmental testing
Part 2-78
Test Cab: Damp heat, steady state IEC 60410, Sampling plans and procedures for inspection by attributes IEC 60617, Graphical symbols for diagrams IEC 60915, Capacitors and resistors for use in electronic equipment – Preferred dimensions of shaft ends, bushes and for the mounting of single-hole, bush-mounted, shaft-operated electronic components IEC 61249-2-7, Materials for printed boards and other interconnecting structures – Part 2-7: Reinforced base materials clad and unclad – Epoxide woven E-glass laminated sheet of defined flammability (vertical burning test), copper-clad IECQ 001002-3, IEC Quality Assessment System for Electronic Components (IECQ) – Rules of procedure – Part 3: Approval procedures
IECQ 001005, see www.iecq.org\certificates for relevant information ISO 1000, SI units and recommendations for the use of their multiples and of certain other units SIST EN 60393-1:2009

– 10 – 60393-1 © IEC:2008(E) ISO 9000, Quality management systems – Fundamentals and vocabulary 2 Technical data 2.1 Units and symbols Units, graphical symbols and letter symbols should, whenever possible, be taken from the following publications: –
IEC 60027-1; –
IEC 60050; –
IEC 60617; –
ISO 1000. When further items are required they should be derived in accordance with the principles of the publications listed above. 2.2 Terms and definitions For the purposes of this document, the following terms and definitions apply. 2.2.1
type group of components having similar design features and the similarity of whose manufacturing techniques enables them to be grouped together for quality conformance inspection. They are generally covered by a single detail specification NOTE 1 Components described in several detail specifications may, in some cases, be considered as belonging to the same type and may therefore be grouped for quality assessment purpose.
NOTE 2 Mounting accessories are ignored provided they have no significant effect upon the test results. NOTE 3 Ratings are to be given in the detail specification. 2.2.2
style subdivision of a type, generally based on dimensional factors, which may include several variants, generally of a mechanical order 2.2.3
grade term indicating additional general characteristics concerning the intended application, for example, long-life applications which may only be used in combination with one or more words (for example, long-life grade) and not by a single letter or number. Figures to be added after the term “grade” should be Arabic numerals 2.2.4
variant subdivision within a style having specific dimensions for some part of its construction, for example, terminals, shaft flats or length (see Annex F) 2.2.5
family (of electronic components) group of electronic components which predominantly displays a particular physical attribute and/or fulfils a defined function 2.2.6
subfamily (of electronic components) group of components within a family manufactured by similar technological methods SIST EN 60393-1:2009

60393-1 © IEC:2008(E) – 11 – 2.2.7
category temperature range range of ambient temperatures for which the potentiometer has been designed to operate continuously; this is defined by the temperature limits of its appropriate category 2.2.8
upper category temperature maximum ambient temperature for which a potentiometer has been designed to operate continuously at that portion of the rated dissipation which is indicated in the category dissipation (see 2.2.13) 2.2.9
lower category temperature minimum ambient temperature for which a potentiometer has been designed to operate continuously 2.2.10
critical resistance resistance value at which the rated voltage is equal to the limiting element voltage. Below the critical resistance the maximum voltage which may be applied across the terminals of a potentiometer is the rated voltage. Above that value the maximum voltage is the limiting element voltage (see 2.2.12, 2.2.14 and 2.2.15) 2.2.11
nominal total resistance resistance value for which the potentiometer has been designed and which is generally marked upon the potentiometer 2.2.12
rated dissipation maximum allowable dissipation between terminals a and c (see 2.2.29) of a potentiometer at an ambient temperature of 70 °C under the conditions of the electrical endurance test at 70 °C which will result in a change in resistance not greater than that specified for that test NOTE 1 In practice, the dissipation is modified by the following conditions. NOTE 2 For high values of resistance, the limiting element voltage (see 2.2.15) may prevent the rated dissipation being attained NOTE 3 For the dissipation at temperatures other than 70 °C, reference should be made to the rating graphs in the relevant detail specification NOTE 4 For situations where only terminals a and b or b and c
are being used and the control shaft is set at an angle less than 100 % of the effective electrical travel, the limiting moving contact current (see 2.2.17) should also be taken into account. 2.2.13
category dissipation maximum allowable dissipation under continuous load at an ambient temperature equal to the upper category temperature, normally expressed as a percentage of the rated dissipation NOTE The category dissipation may be zero. 2.2.14
rated voltage d.c. or a.c. r.m.s. voltage calculated from the square root of the product of the nominal total resistance and the rated dissipation NOTE At high values of resistance, the rated voltage may not be applicable because of the size and construction of the potentiometer (see 2.2.10, 2.2.12 and 2.2.15). SIST EN 60393-1:2009

– 12 – 60393-1 © IEC:2008(E) 2.2.15
limiting element voltage maximum d.c. or a.c. r.m.s. voltage which may be applied across the element of a potentiometer
NOTE 1 When the term “a.c. r.m.s. voltage” is used in this specification, the peak voltage should not exceed 1,42 times the r.m.s. value. NOTE 2 This voltage should only be applied to potentiometers when the resistance value is equal to, or higher than, the critical value. 2.2.16
insulation voltage maximum peak voltage under continuous operating conditions which may be applied between the potentiometer terminals and other external conducting parts connected together NOTE The value of the insulation voltage should be not less than 1,42 times the limiting element voltage at normal air pressure. Under conditions of low air pressure, the value of the insulation voltage will be less and should be given in the detail specifications. 2.2.17
limiting moving contact current maximum current that may be passed between the resistance element and the moving contact
2.2.18
variation of resistance and voltage output ratio with temperature can be expressed either as a temperature characteristic or as a temperature coefficient as defined below 2.2.18.1 temperature characteristic of resistance maximum reversible variation of resistance produced over a given temperature range within the category temperature range,
expressed normally as a percentage of the resistance related to a reference temperature of 20 °C 2.2.18.2 temperature coefficient of resistance (ér) relative variation of resistance between two given temperatures (mean coefficient), divided by the difference in temperature producing it,
preferably
expressed in parts per million per °C (10-6P/K) NOTE It should be noted that use of the term does not imply that any degree of linearity for this function, nor should any be assumed. 2.2.18.3 temperature coefficient of output ratio (éoB)
relative variation of voltage output ratio between two given temperatures (mean coefficient) at fixed values of setting and load of the moving contact, divided by the difference in temperature producing it,
preferably
expressed in parts per million per °C NOTE 1 The value of .B0
may be different for different settings of the output ratio. NOTE 2 It should be noted that the use of the term does not imply that the function exhibits any degree of linearity, nor should any be assumed. 2.2.19
visible damage damage which reduces the usability of the potentiometer for its intended purpose SIST EN 60393-1:2009

60393-1 © IEC:2008(E) – 13 – 2.2.20
potentiometer component for use as a voltage divider with three terminals of which two are connected to the ends of a resistive element and the third is connected to a moving contact which can be moved
mechanically along the resistive element 2.2.21
pre-set or trimmer (or trimming) potentiometer potentiometer designed for relatively infrequent adjustment 2.2.22
lead-screw actuated potentiometer potentiometer having a lead-screw as multi-turn actuating device 2.2.23
ganged potentiometers potentiometers consisting of two or more sections operated by a common operating shaft. The number of sections shall be included in the description, for example, 2-ganged potentiometer or 4-ganged potentiometer 2.2.24
dual concentric potentiometers potentiometers consisting of two sections operated independently by concentric operating shafts 2.2.25
shaft-sealed potentiometer potentiometer in which a shaft seal is provided to prevent particles and fluid from passing from the exterior of the potentiometer to the interior by way of the shaft bearing
(see Figure 1) 2.2.26
shaft-sealed and panel-sealed potentiometer potentiometer in which a shaft seal and a panel seal are provided to prevent particles and fluid from entering any equipment in which this potentiometer is mounted (see Figure 2) 2.2.27
fully sealed potentiometer potentiometer in which a shaft seal is provided and the housing of the potentiometer is designed to prevent particles and fluid from passing from the exterior of the potentiometer to the interior (see Figure 3) In some cases a panel seal may additionally be provided. Such a potentiometer is called a “fully sealed potentiometer” (see Figure 3). SIST EN 60393-1:2009

– 14 – 60393-1 © IEC:2008(E) Housing not sealedShaft Bush Shaft sealing IEC
604/08 Housing not sealed Shaft
Bush Shaft sealing Panel sealing IEC
605/08
Figure 1 – Shaft-sealed potentiometer Figure 2 – Shaft- and panel-sealed potentiometer Sealed Housing Shaft Bush Shaft sealing Panel sealing IEC
606/08
Figure 3 – Fully sealed potentiometer 2.2.28
direction of rotation defined as clockwise or counter-clockwise when viewing the face of the potentiometer which includes the means of actuation (see Annex G). When doubt exists, the reference face shall be marked in accordance with the detail specification 2.2.29
designation of terminals preferred designation of the three terminals of the potentiometer is: a is the end terminal electrically nearest to the moving contact with the shaft set
fully counter-clockwise as defined in 2.2.28; b is the terminal of the moving contact; c is the other end terminal. NOTE The numerals 1, 2 and 3, or colours yellow, red and green, may be used as alternatives to a, b and c, respectively. When terminals are marked, the marking should be in accordance with this clause. Additional lettersT, T numbers or colours for other terminals should be allocated in the relevant specification. 2.2.30
variable resistor
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