scope:

This standard specifies the requirements and resistance versus temperature relationship for indus trial platinum resistance thermometers later referred to as "thermometers" and industrial platinum resistance temperature sensors later referred to as "platinum resistors" whose electrical resistance is derived by defined function of temperature. The standard applies to platinum resistors whose temperature coefficient α, defined as R C R R ⋅ ° − = 100 0 α 100 0 , is conventionally written as α = 3,851⋅10-3 °C-1, where R100 is the resistance at t = 100 °C and R0 is the resistance at t = 0 °C. Values of temperature in this standard are in terms of the International Temperature Scale of 1990, ITS-90. Temperatures in degrees Celsius are denoted by the symbol t, except in Table A.1 where the full nomenclature t90/°C is used. The standard covers platinum resistors or thermometers for all or part of the temperature range -200 °C to +850 °C with different tolerance classes, which may cover restricted temperature ranges. For temperature/resistance relationships with uncertainties less than 0,1 °C, which are possible only for platinum resistors or thermometers with exceptionally high stability and individual calibration, a more complex interpolation equation than is presented in this standard may be necessary. The specification of such equations is outside the scope of this standard. In order for a thermometer to be compliant with this standard it shall be made from a platinum resis tor which is compliant with this standard.