The Scope of Accreditation for a calibration laboratory is the official document that contains the calibration activities and measurement details for which the laboratory is accredited to perform.
The Scope contains the calibration parameters, the types of equipment that can be calibrated, the laboratory measurement capability and the specific standard or calibration procedures used.
The Scope of Accreditation is an important requirement of ISO/IEC 17025. ISO/IEC 17025:2017 Clause 5.3 states that ‘The laboratory shall define and document the range of laboratory activities for which it conforms with this document.” It is used by the accreditation body during the auditing process to determine that the laboratory has the resources and technical competence to provide the services defined in the Scope.
Each accreditation body its their own requirements for the format of the Scope of Accreditation so any laboratory seeking accreditation must read the specific requirements and guidelines for the proper completion of the scope.
The Scope is not only used by the laboratory, but it is an important source of information for the laboratory’s customers. The Scope is typically formatted in a manner that allows potential customers to easily compare various laboratory measurement capabilities to select the proper laboratories to meet their measurement requirements.
Contents of the Scope of Accreditation
The main sections of the Scope of Accreditation are broken down into calibration sub-disciplines such as Dimensional, Electrical, Mechanical, Time & Frequency, and Thermodynamics.
The columns for the Scope of Accreditation contain four main headings that are listed below.
This column contains the sub-discipline function or the type of equipment that fits into that category. For example, for the Dimensional sub-discipline, the parameter could be listed as Length, or it could be broken down further into the specific equipment types, such as Calipers, Micrometers, Dial Indicators, etc. with the specific measurement values for each type. It may be more beneficial to the laboratory’s customers to list the equipment that the customer would likely be searching for.
This column lists the appropriate range of the laboratory calibration capabilities. It will typically list the minimum and maximum measurement values that can be calibrated for that particular item. The range is important to determine if the laboratory has a specific capability for a measurement type.
CMC stands for the ‘Calibration and Measurement Capability’ of the laboratory. This column contains the measurement uncertainty values for each of the measurement ranges listed in the Scope. These values are typically calculated by using the ‘Best Existing Device’ that the laboratory has available to calculate the measurement uncertainty and the laboratory cannot report a measurement uncertainty that is lower than the recorded value on the Scope. For most customers, their equipment will usually have resolutions or repeatability values greater than the laboratory’s equipment, so the reported measurement uncertainty for a customer’s device will be greater than the CMC value.
This column contains any additional information required for the understanding of the measurement parameters in the Scope. This column usually lists the specific equipment standards that the laboratory uses for the measurement or any additional comments such as measurement methods or accuracy classifications.
Some of the parameters or columns listed will have superscripts at the end of the description in the specific column. The superscripts refer to the section at the end of the Scope where information is provided to further clarify the information in the Scope or to designate which measurements the laboratory can perform for field calibrations.