This part of IEC 62059 provides one of several possible methods for estimating product life characteristics by accelerated reliability testing. Acceleration can be achieved in a number of different ways. In this particular standard, elevated, constant temperature and humidity is applied to achieve acceleration. The method also takes into account the effect of voltage and current variation. Of course, failures not (or not sufficiently) accelerated by temperature and humidity will not be detected by the application of this standard. Other factors, like temperature variation, vibration, dust, voltage dips and short interruptions, static discharges, fast transient burst, surges, etc. - although they may affect the life characteristics of the meter - are not taken into account in this standard; they may be addressed in future parts of the IEC 62059 series. This standard is applicable to all types of metering equipment for energy measurement, tariff- and load control in the scope of IEC TC 13. The method given in this standard may be used for estimating (with given confidence limits) product life characteristics of such equipment prior to and during serial production. This method may also be used to compare different designs.