The purpose of the IEC 62755 standard N42 data format is to facilitate manufacturer-independent transfer of information from radiation measurement instruments used for detection of illicit trafficking of radioactive materials.
The IEC 62755 standard specifies the XML data format that shall be used for both required and optional data to be made available by radiation measurement instruments. The performance requirements for these types of instruments are described in other IEC standards. The output from these instruments consists of measurement data and results of any analysis performed by the radiation measurement instrument. The IEC 62755 standard does not address instrument control, data transmission protocols, or the physical media used for communications.
The structure of the data is described by an XML schema. The schema file allows XML parsers to validate the format of instrument data document: it defines the standard names for data elements and attributes, whether or not they are optional or required for each class of instrument, and the hierarchical relationships between them. The IEC 62755 standard provides several examples to assist the implementer in the use and application of this standard.
This standard was published in 2012 and amended in 2020.
The structure of the data is described by the XML Schema (.xsd) file. This schema file allows XML parsers to validate the format of instrument data documents for this IEC standard: it defines the standard names for data elements and attributes, whether or not they are optional or required for each class of instrument, and the hierarchical relationships between them. Examples of N42 documents from different types of radiation measurement instruments for this standard can be downloaded for here.
Additional tools are provided for the N42 format for this IEC standard. These tools include business rules. These rules have been implemented as an ISO Schematron schema.
If there are issues viewing these links, it is possible to download the N42AllFiles.zip file that contains all the examples, the schemas (N42.xml and N42SchemaAddin.xsd) and the schematron schema (N42.sch).
An N42 radiation detector data format validator is available at: https://secwww.jhuapl.edu/n42/Account/LogOn