I.S. EN 62059-31-1:2008

FOREWORD
INTRODUCTION
1 Scope
2 Normative references
3 Terms and definitions
4 Symbols, acronyms and abbreviations
5 Description of quantitative accelerated life tests
   5.1 Introduction
   5.2 The life distribution
   5.3 The life-stress model
6 The Weibull distribution
   6.1 Introduction
   6.2 Graphical representation
   6.3 Calculation of the distribution parameters
        6.3.1 Input data to be used
        6.3.2 Ranking of the time to failure
        6.3.3 Reliability/unreliability estimates
        6.3.4 Calculation of the parameters
7 The life-stress model
   7.1 General
   7.2 Linear equation of the acceleration factor
   7.3 Calculation of parameters n and E[a]
8 The quantitative accelerated life testing method
   8.1 Selection of samples
   8.2 The steps to check product life characteristics
   8.3 Procedure for terminating the maximum stress level
        test
   8.4 Procedure to collect time to failure data and to repair
        meters
9 Definition of normal use conditions
   9.1 Introduction
   9.2 Temperature and humidity conditions
        9.2.1 Equipment for outdoor installation
        9.2.2 Equipment for indoor installation
   9.3 Temperature correction due to variation of
        voltage and current
        9.3.1 Definition of the normal use profile of voltage
               and current
        9.3.2 Measurement of the meter internal temperature
               at each current and voltage
        9.3.3 Calculation of the meter average internal
               temperature
   9.4 Other conditions
10 Classification and root cause of failures
11 Presentation of the results
   11.1 Information to be given
   11.2 Example
12 Special cases
   12.1 Cases of simplification
        12.1.1 Minor evolution of product design
        12.1.2 Verification of production batches
   12.2 Cases when additional information is needed
        12.2.1 The beta parameter changes significantly from
               maximum stress level to medium or low stress
               level
        12.2.2 Fault mode different between stress levels
Annex A (informative) Basic statistical background
Annex B (informative) The characteristics of the Weibull
        distribution
Annex C (informative, see also draft IEC 62308) Life-stress
        models
Annex D (normative) Rank tables
Annex E (normative) Values of the Gamma function tau(n)
Annex F (normative) Calculation of the minimum duration
        of the maximum stress level test
Annex G (informative) Example
Annex ZA (normative) Normative references to international
         publications with their corresponding European
         publications
Bibliography
INDEX

Provides one of several possible methods for estimating product life characteristics by accelerated reliability testing.